INVESTIGATING THE ACTIVITY OF QUININE ANALOGS VERSUS CHLOROQUINE RESISTANT PLASMODIUM FALCIPARUM

Theresa Dinio Abad

A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment of the Requirements for the Degree of Master of Science

Department of Chemistry and Biochemistry

University of North Carolina Wilmington

2012

Approved by

Advisory Committee

John A. Tyrell Jeffrey L. C. Wright

Jeremy B. Morgan

Accepted by

Dean, Graduate School

TABLE OF CONTENTS

ABSTRACT ...... iii

ACKNOWLEDGEMENTS ...... iv

DEDICATION ...... v

LIST OF TABLES ...... vi

LIST OF FIGURES ...... vii

LIST OF SCHEMES...... viii

INTRODUCTION ...... 1

RESULTS AND DISCUSSION ...... 11

Synthesis of Cinchona Alkaloid Vinyl Derivatives ...... 11

Synthesis of QN and eQN Amino Derivatives ...... 15

Antiplasmodial Activity ...... 19

β-Hematin Crystal Growth Inhibition Data ...... 23

CONCLUSIONS & FUTURE WORK ...... 26

EXPERIMENTAL ...... 28

REFERENCES ...... 52

APPENDIX ...... 59

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ABSTRACT

Plasmodium falciparum, the deadliest form of the malarial parasite, has developed resistance against nearly all man-made antimalarials within the past century. However, quinine, the first malaria treatment, remains efficacious worldwide. We have developed a structure-activity relationship study around vinyl and hydroxyl modifications on quinine that may help to understand the resistance mechanism employed by the parasite. Several vinyl derivatives have shown high antiplasmodial activity in chloroquine resistant and sensitive strains with lower IC50 values than quinine, whereas the hydroxyl variations, specifically, the amino compounds, have exhibited low activity in the 1-10 μM range.

Moreover, β-hematin studies for the Cinchona vinyl derivatives indicate there is no correlation between the antiplasmodial activity and the ability to inhibit hemozoin growth. This may further suggest that alternative targets may be responsible or possibly a differential interaction with the same target.

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ACKNOWLEDGEMENTS

At UNCW, I have had the privilege to work with many talented individuals. My advisor, Jeremy B. Morgan, took a chance on his first 3 female graduate students, myself,

Jen Cockrell and Katie Scholl. I think it was truly meant to be this way as I believe we all created a healthy and fun work environment. Not only did they all help to train me, but they pushed me to work efficiently and to succeed in everything that I do. They have all been great inspirations and motivators.

Jeremy has been a great mentor and advisor. He was always there whenever I had issues with my experiments or with life, in general. Thank you for the great project and for having me a part of the lab. Thank you, Jen and Katie, for the memories (too many to list here) and for making UNCW a home away from home. Special thanks go to Andrew

McGinniss for giving me a great start to this project, to Paige Street for her help in this work and to the rest of the Morgan lab for our fun times inside and outside of lab. I’d also like to acknowledge our collaborators, Alexander P. Gorka and Dr. Paul D. Roepe, for their assistance in the biological studies.

Lastly, I would like to acknowledge the numerous individuals who have directly or indirectly affected my educational experience. This includes, but is not limited to, my fellow graduate students, the faculty members (especially those who serve on my thesis committee, John Tyrell and Jeffrey L.C. Wright), the chemistry & biochemistry department staff, and the undergraduates in my teaching labs. Thank you everyone for helping me grow during my time at UNCW. I truly look forward to utilizing my knowledge of organic chemistry in engineering applications to create advances in biotechnology.

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DEDICATION

I would like to dedicate this thesis to my husband, Daniel P. Abad, Jr. Thank you for your love, support and understanding during the long days of work/ school, short nights at home and the weekend visits to the lab.

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LIST OF TABLES

Table Page

1. Cost of antimalarial options ...... 3

2. IC50 data against HB3 and Dd2 parasite strains for QN-1, QN-2, and QN ...... 8

3. Vinyl group modifications to Cinchona alkaloids ...... 11-13

4. Protected QN and eQN amino derivatives ...... 17

5. IC50 screen results for Cinchona alkaloid derivatives...... 20

6. β-Hematin inhibitory IC50 data for select Cinchona alkaloids at pH 5.2 and 5.6 ...... 24

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LIST OF FIGURES

Figure Page

1. The spread of malaria through humans and mosquitoes ...... 1

2. Quinoline-based antimalarial drugs ...... 2

3. Artemisinin-based antimalarial drugs ...... 3

4. The compound used to design a pharmacophore model on the antimalarial activity of various compounds ...... 5

5. Illustration of important binding functional groups within quinine determined by tryptanthrin pharmacophore ...... 5

6. Proposed mechanism for the Heck reaction...... 7

7. Positive modifications on QN from previous work ...... 7

8. Aryl group modifications applied to Cinchona alkaloids at the vinyl group ...... 8

9. Cinchona alkaloids...... 8

10. Proposed five-membered ring formation when QN binds to heme...... 9

11. Trans configuration of QN-4 indicated by the coupling constant ...... 14

12. Initial screening of the amino QN series in Dd2 and HB3 ...... 21

13. Initial screening of the amino eQN series in Dd2 and HB3 ...... 22

14. Inactive compound, QN-5, from a previous series ...... 23

15. Plot of β-hematin inhibitory IC50 vs. antiplasmodial IC50 ...... 25

16. Future protecting groups on amino eQN (21) ...... 27

17. Derivatives with other hydrogen donating groups on carbon 9 of QN ...... 27

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LIST OF SCHEMES

Scheme Page

1. Reaction scheme for modifying Cinchona alkaloids at the vinyl group ...... 6

2. Synthesis of 9-amino-(9-deoxy)quinine derivatives ...... 9

3. General reaction for Cinchona alkaloid vinyl derivatives ...... 11

4. Synthesis of epi-quinine (eQN)...... 15

5. Synthesis of 9-amino QN compounds ...... 16

6. Phthalimide derivatives ...... 18

7. Benzyl derivatives...... 18

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INTRODUCTION

Malaria is one of the top 5 infectious diseases in the world, behind respiratory infections, HIV/AIDS, diarrheal diseases, and tuberculosis1. The cause of this disease is a single-celled parasite called Plasmodium. With its potential to rapidly progress into a severe illness and death, Plasmodium falciparum is the most deadly parasite. Currently, about half of the world’s population, mostly those living in the poorest countries, is at risk of contracting this disease. More than 200 million malaria cases lead to an estimated

781,000 annual attributed deaths. Moreover, nearly 85% of the reported deaths occur in

Africa alone.1,2

Malaria is mainly transmitted by female Anopheles mosquitoes. Uninfected mosquitoes obtain a strain of Plasmodium when they feed on humans who harbor the parasites in their liver and bloodstream. Thus, humans and mosquitoes play complementary roles in a cycle where the disease continues to spread.2-4

Figure 1. The spread of malaria through humans and mosquitoes.

Symptoms of malaria include fever, headache, nausea, chills, and other flu-like symptoms. When a treatment is not available or the parasites are resistant to them, the infection can progress rapidly to become life-threatening. Malaria can kill by infecting and destroying red blood cells and by clogging capillaries that carry blood to the brain or

other vital organs, leading to serious organ failures. Some manifestations of severe malaria include coma, seizures, acute renal failure, and acute respiratory distress syndrome.4

The first known treatment of malaria was found in the bark of Cinchona and

Remijia species, which are evergreen trees, originally part of the Andes Mountains from

Venezuela to Bolivia. Natives called the Cinchona tree “quina-quina” (meaning “bark of barks”) and they chewed the bark for its antipyretic properties.5 In 1640, Spanish Jesuits,

Father Antonio de la Calancha in Perú and Cardinal Juan de Lugo in Europe, introduced the bark into medical use to treat malaria. Almost 200 years later, French scientists

Pierre Joseph Pelletier and Joseph Bienaimé Caventou isolated quinine (1, Figure 2), one of the major alkaloids in the bark with antimalarial activity.5 Thus, quinine (QN) became the first line of therapy against various strains of the parasite.

Figure 2. Quinoline-based antimalarial drugs.

When the Japanese took over the supply of QN during World War II, the need for a synthetic antimalarial became a priority.6 Since that time, challenges have always been present in finding an antimalarial compound that is affordable and efficacious. Reports outlining the synthesis of quinine have been laborious, requiring multiple steps with low overall yield.7, 8 Furthermore, stereocontrol is a great difficulty as QN has 4 chiral centers, which can lead to a possibility of 16 isomeric structures. Another approach was

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to synthesize compounds analogous to QN, such as chloroquine (2), mefloquine (3), and primaquine (4), each of which contains quinoline as an aryl functional group (Figure 2).

However, Plasmodium parasites began to develop unacceptable levels of worldwide resistance to these analogs within a few decades after introduction.4,9

Figure 3. Artemisinin-based antimalarial drugs.

Table 1. Cost of antimalarial options.10 Average Cost per Antimalarial Treatment Adult Rx (US$) chloroquine 0.07 sulfadoxine-pyrimethamine 0.08 quinine 1.35 artemether combination 2.50 artesunate + mefloquine 5.38

Artemether (5) and artesunate (6), have gained favor as the prominent replacement therapy (Figure 3); however, the costs of these artemisinin-based combination therapies (ACTs) are comparatively high (Table 1).10 These treatments are derived from artemisinin (7), a compound found in the leaves of a Chinese plant,

Artemisia annua.11 Moreover, therapeutic levels of these replacements are not sustained for significant periods. This leads to frequent dosing and at least a 7-day medication regiment to completely eradicate the disease. A 3-day course may only be able to reduce the parasite burden and have clinical improvement, but the disease often recurs.11,12 On a final note, artemisinin resistance has begun to emerge in Southeast Asia.13,14 If this

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replacement therapy follows the historical trend of decreased efficacy, a new antimalarial compound will definitely be in demand within the next few years.

While the search for a novel drug target and new lead structure for the treatment of malaria is an active venture,15,16 an alternate consideration is to utilize a lead structure from nature, such as QN. The World Health Organization (WHO) currently recommends the use of QN in the absence of ACTs to treat chloroquine resistant (CQR) P. falciparum malaria. Okombo et al. has also stated that “there is no evidence of widespread [in vivo] resistance worldwide despite the fact that this drug [QN] has been in use for more than

400 years.”17 The molecular mechanism of action of QN has not been fully explained. It is believed that QN targets heme detoxification within the digestive vacuole of the malaria parasite.18-20 Thus, in terms of structure activity relationship (SAR), there is still much to learn about QN and other Cinchona alkaloids.

Roepe et al. has reported that the removal of the QN hydroxyl or the rigid quinuclidyl ring lowers heme affinity, hemozoin inhibition efficiency, and antiplasmodial activity. On the other hand, elimination of the vinyl or methoxy group does not demonstrate the same effects.21 de Dios et al. has shown that resistant parasites can be understood to confer resistance to chloroquine and QN in different ways due to the way each bind to heme.22 Previous work in our group has also reported that certain modifications on the vinyl group of QN have exhibited high antimalarial activity against both chloroquine-sensitive (CQS) and chloroquine-resistant (CQR) P. falciparum.23 To expand on this current data, we seek to continue varying the vinyl group of QN and the remaining Cinchona alkaloids and change the hydroxyl into an amino group. These

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compounds will also be tested for antiplasmodial activity as these may provide insight into a possible differential mode of action of QN in sensitive vs. resistant strains.

The first objective was to modify Cinchona alkaloids at the vinyl group. In considering different moieties to vary on QN, the alkene provided an area for rapid modification and the process could be cost-effective. A previous study made a pharmacophore model using a program called Catalyst®24 to examine anti-malarial activity of various compounds. The model was based on an alkaloid from a Taiwanese medicinal plant, tryptanthrin25 (Figure 4) and its substituted derivatives.

Figure 4. The compound used to design a pharmacophore model on the antimalarial activity of various compounds.25

Figure 5. Illustration of important binding functional groups within quinine determined by tryptanthrin pharmacophore.25

Several anti-malarial drugs were placed into the same pharmacophore model and

QN received the highest “Best-Fit Score.” It exhibited the two necessary hydrogen bonding requirements with the molecule’s alcohol and tertiary amine groups. The vinyl and quinoline moieties take part in the two required aromatic hydrophobic interactions

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(Figure 5).25 Therefore, modifications at the alkene that maintain the hydrophobic interaction would still fit this model.

A library of unique QN derivatives from the Morgan group has been synthesized by an inexpensive, one-step reaction (Scheme 1)23 that relied on the versatile palladium- catalyzed Heck cross-coupling method (Figure 6).14-16 The addition of the aryl group across the double bond kept the necessary aromatic hydrophobic region intact. The stereochemistry of the core alkaloid, the hydroxyl, and the quinuclidyl ring also remain intact. Moreover, this reaction is amenable to scale-up for commercial production.

Scheme 1. Reaction scheme for modifying Cinchona alkaloids at the vinyl group.

Initiation of the Heck reaction begins with an in situ reduction of palladium(II) to palladium(0) (8, Figure 6). Oxidative addition of the aryl bromide (9) to Pd(0) generates an aryl Pd(II) complex (10). The olefin (11) is coordinated by the Pd(II) intermediate

(12) and is followed by insertion of 11 between the carbon–Pd(II) bond, which favors syn addition to produce 13. A β-hydride elimination of this product occurs to generate the desired trans olefin (15). If the substrate contains an alternate β-hydrogen, it can be improperly eliminated giving an undesired product (14). Reductive elimination of HBr from 16, with help from a base, completes the catalytic cycle regenerating 8, the Pd(0) species. Products of the Heck reaction predominately show trans stereochemistry

6

because the alkene addition and β-hydride elimination steps occur in a syn fashion with steric minimization.

Figure 6. Proposed mechanism for Heck reaction.

Figure 7. Positive modifications on QN from previous work.

In preliminary data, the synthetic QN derivatives from certain aryl bromides, seen in Figure 7, have exhibited high antimalarial activity against both CQS (HB3) and CQR

23 (Dd2) P. falciparum strains. Activity was based on IC50 values, which give the amount of a compound necessary to inhibit the growth of a biological system by half. Analysis of the data (Table 2) shows that compounds QN-1 and QN-2 are not as potent against the

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CQS strain compared to QN.23 However, the CQR data shows a 4-fold increase in QN concentration is required to inhibit the Dd2 (CQR) parasite strain. Compound QN-1 hardly exhibited an increase in concentration from 427 to 485 nM, while compound QN-

23 2 demonstrated a decrease. Based on the IC50 data, it appears that these compounds may have bypassed the parasitic resistance mechanism that QN encounters.

Table 2. IC50 data against HB3 and Dd2 parasite strains for QN-1, QN-2, and QN.21,23

Compound HB3 (CQS) IC50 (nM) Dd2 (CQR) IC50 (nM) QN 81 ± 8 320 ± 50 QN-1 427 ± 4 485 ± 6 QN-2 428 ± 4 318 ± 2 a IC50 values are an average of triplicate measurements and reported ± S.E.M.

Figure 8. Aryl group modifications applied to Cinchona alkaloids at the vinyl group.

To expand on this data, those positive modifications and the new aryl groups in

Figure 7 and 8 have been applied to QN and the other Cinchona alkaloids seen in Figure

9. Each of these new alkaloids will be tested for activity against CQS and CQR P. falciparum. Although the primary focus on this objective is antimalarial drug synthesis, it should be noted that Cinchona alkaloids are efficient ligands and catalysts in organic synthesis,26 which presents further commercialization opportunities.

Figure 9. Cinchona alkaloids.

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The second objective was to synthesize derivatives from 9-amino-(9-deoxy)-epi- quinine (21) and 9-amino-(9-deoxy)quinine (22) (Scheme 2). These compounds offered another route to test the relationship of the hydroxyl group of QN. As stated before, the removal of the QN hydroxyl drastically lowers heme affinity, hemozoin inhibition efficiency, and antiplasmodial activity. The previous study has also suggested that there is an important intramolecular hydrogen bond between the hydroxyl group and the nitrogen of the quinuclidyl of QN (Figure 10).21 As an amino group can also act as a hydrogen donor, it was insightful to study the effect of various amine protecting groups on anti-malarial activity in CQR and CQS P. falciparum strains.

Scheme 2. Synthesis of 9-amino-(9-deoxy)quinine derivatives.

Figure 10. Proposed five-membered ring formation when QN binds to heme.

It is also important to note that the antimalarial activity of epi-quinine (eQN, 20) has been reported to be 100 times lower than QN,27 which may suggest that other derivatives with the same configuration could exhibit the same characteristics. Crystal structure analysis illustrated that the direction of quinuclidyl nitrogen and hydroxyl group

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relative to each other in the salt forms of QN and eQN was the predominant factor influencing antimalarial activity. However, the amino series with the 9S configuration still contains the necessary hydrogen bonding capability and it is possible that the various protecting groups may have a positive effect on the compounds’ activity. Furthermore, synthesis for these amino compounds was mainly for catalysts and ligands28-31 and none have been tested for biological activity.

28 Amino derivatives were synthesized following a known procedure. SN2 addition of azide at carbon C9 replaced the hydroxyl functional group of QN via a

Mitsunobu-like reaction (Scheme 2). This resulted in an inversion of configuration at this site. Triphenylphosphine reduced the azide into an amine via a Staudinger reduction and retains the C9 stereochemistry.28 Lastly, amine protecting groups (PG) have been varied to create the various derivatives. eQN (20), synthesized by a modified Hoffman procedure,32 will also be used in the same procedure to yield compounds with the 9R configuration.

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RESULTS & DISCUSSION

Synthesis of Cinchona Alkaloid Vinyl Derivatives

Following Scheme 3, fourteen novel Cinchona alkaloid derivatives were synthesized and purified by flash column chromatography (FCC). Reaction substrates with the corresponding product structures are listed in Table 3. Typically, two equivalents of an aryl bromide were used to modify the vinyl group. However, entry 7 required 4 equivalents of the corresponding halide. Overall, isolated product yields ranged from 31–93% with an average percent yield of two or more runs (Table 3).

Scheme 3. General reaction for Cinchona alkaloid vinyl derivatives. The terminal alkene is representative of the vinyl group on quinine, cinchonidine, quinidine, and cinchonine.

TABLE 3. Vinyl group modifications to Cinchona alkaloids. Aryl Entry Compound #a Product % Yield Bromide

1 QN-3 62

2 QN-4 60

aCompound number refers to starting olefin with QN = quinine. See Figure 9 for the remaining olefin abbreviations.

11

Table 3 continued

3 CD-1 52

4 CD-2 93

5 CD-3 51

6 CD-4 64

7 QD-1 49

8 QD-2 84

9 QD-3 31

aCompound number refers to starting olefin with QN = quinine. See Figure 9 for the remaining olefin abbreviations.

12

Table 3 continued

10 QD-4 66

11 CN-1 55

12 CN-2 65

13 CN-3 42

14 CN-4 43

aCompound number refers to starting olefin with QN = quinine. See Figure 9 for the remaining olefin abbreviations.

To ensure reaction completion after the 24 hour reflux, 1H-NMR was taken of the crude material. The spectra confirmed that residual alkaloid starting material would not interfere with the purification process. After isolating the product, structures were verified by 1H-NMR and 13C-NMR. When a successful Heck reaction occurs, alkene protons in the 1H-NMR indicated trans configuration with a coupling constant of 15.6

Hz, a higher chemical shift compared to the starting material, and a 1:1 integrated ratio instead of the 2:1 ratio from the initial terminal olefin (Figure 11).

13

Figure 11. Trans configuration of CD-1 indicated by the coupling constant, Jab = 15.6 Hz.

Purification of Cinchona alkaloid derivatives by FCC with silica gel proved to be an extensively meticulous endeavor. Side products from the reactions added another dimension of difficulty, as some of them had very similar retention factor (Rf) values to desired products. These side products were most likely from the reaction reagents, not including the Cinchona alkaloid. Previous work opted only to use one solvent system during the purification of QN derivatives.23 For the new compounds, various gradient

FCC solvent systems of dichloromethane (DCM) and methanol (MeOH) were tested in order to maximize purity and yields. The concentration of MeOH ranged from 0-25%.

The gradient solvent systems did provide higher yields in some entries; however, it was not a trend seen in all cases. Product was often discarded, as seen in previous work, because undesired products were almost always present in some of the same fractions; ultimately leading to lower isolated yields. Furthermore, purity was sacrificed in some cases (entries 3, 8, 10–11, 13–14, Table 3) in order to test the activity of the compounds in the CQR and CQS strains. Impurities include the salt form of the product and/or traces of the aryl halide. It is important to note that the starting material

14

themselves were also not 100% pure. The impurities include the dihydro derivatives and trace amounts of stereochemically-related alkaloids in cinchonine and cinchonidine.

The only unsuccessful substrate was 4-bromo-N,N-dimethylaniline with QN. The

Heck reaction occurred, but did not go to completion regardless of a longer reaction time

(48 h) and/or an increase in aryl halide concentration. In every case, olefin peaks of QN were seen in all spectra of the crude material. It is possible that QN was not coordinated by the Pd(II) intermediate that contained the aryl halide. Another cause could be that the aryl bromide was slow to perform the oxidative addition to the Pd(0) species because it is more electron rich.

Synthesis of QN and eQN Amino Derivatives

To create amino derivatives with the same absolute configuration as QN, epi- quinine (eQN, 20) was synthesized via a modified Hoffman procedure (Scheme 4).32

Purified mesylated quinine (23) was further reacted with tartaric acid at reflux to make eQN. An excess of sodium hydroxide was used to precipitate the crude product. FCC yielded an overall 54% yield.

Scheme 4. Synthesis of epi-quinine (eQN).

Starting with QN or eQN, 9-amino-(9-deoxy)-epi-quinine (21) or 9-amino-(9- deoxy)quinine (22), respectively, was synthesized in 2 steps; the Mitsunobu-like reaction

15

28 and the Staudinger reduction (Scheme 5). DIAD and PPh3 formed a phosphonium intermediate that binds to the alcohol from QN or eQN. This activated it as a leaving group. The azide from DPPA acted as a nucleophile and performed an SN2 addition during the Mitsunobu-like reaction. A reduction of the azide into an amine via a

Staudinger reaction and FCC provided an overall 61% average yield for 21 and 44% for

22.

Scheme 5. Synthesis of 9-amino QN compounds.

Following the scheme in Table 4, fourteen 9-amino-(9-deoxy)quinine derivatives were synthesized and purified by FCC. Isolated product yields ranged from 49–96% with an average percent yield of two or more runs. The protection group and the configuration of carbon 9 are listed in the table as well. Typically, a slight excess (1.05 equivalents) of the protecting group and triethylamine (1.2 equivalents) were used. The reaction occurred overnight and isolated products were verified by 1H-NMR, 13C-NMR, and

HRMS. The final products ranged from amides, carbamates, a tosyl protection, and a thiourea. They all provide the hydrogen donating ability and yield derivatives that helped

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to understand the effect of various amine protecting groups on antimalarial activity in

CQR and CQS P. falciparum strains.

Table 4. Protected QN and eQN amino derivatives.

Phthalimide derivatives were also synthesized via reflux in toluene with phthalic anhydride and either 21 or 22 (Scheme 6).33 These compounds offered derivatives that lacked the hydrogen donating ability of the 9-amino group and it is expected that activity would drastically decrease for these. Furthermore, benzyl protected diamines were synthesized via an imine formation with benzaldehyde and either 21 or 22. This was followed by a reduction with sodium borohydride (Scheme 7).34

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Scheme 6. Phthalimide derivatives.

Scheme 7. Benzyl derivatives.

As all of the other compounds protected the 9-amino group with electron withdrawing substituents, the benzyl protection afforded a derivative that lacked this aspect and still maintained the hydrogen donating ability. In having an electron-donating group on the amine, it is expected that the activity would be relatively higher in comparison to all other derivatives. FCC gave yields ranging from 70–98% for the phthalimide and benzyl protected compounds.

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Antiplasmodial Activity

A growth inhibitory assay was employed to the Cinchona alkaloid vinyl derivatives, the amino QN series and the amino eQN compounds. This screen was for antiplasmodial activity in HB3 (CQS) and Dd2 (CQR) strains of P. falciparum. The biological testing was completed by the Roepe lab at Georgetown University using the

SYBR Green I-based plate method.35 Initial screening experiments used three compound concentrations, 0.1, 1, and 10 μM, to evaluate efficacy against both parasitic strains. Full half maximal inhibitory concentration (IC50) binding curves were conducted for compounds that exhibited strong enough growth inhibition in the initial screening. IC50 curves are commonly sought during drug development because they express the amount of a compound necessary to inhibit a biological system by half. IC50 values for QN and the other Cinchona alkaloids were sought and are shown in Table 5.21

Some trends emerge when considering the structure-activity relationships of these

Cinchona derivatives. Modification of all four Cinchona alkaloids with aromatics containing para-substituted withdrawing groups was generally beneficial. A para-phenyl

(QN-3, CD-3, QD-3, and CN-3) or para-ester (QN-2, CD-2, QD-2, and CN-2) aryl modification resulted in improved activity vs. the CQR Dd2 strain, relative to QN. The noticeable outliers to this trend were derivatives containing either para- or meta- trifluoromethyl substituted aryls (CD-4, QD-1, and CN-1). The explanation for the differential antiplasmodial activity of ortho/para vs. meta substituted derivatives could lie in steric and/or electronic interaction with non-heme drug targets, such as the P. falciparum chloroquine resistance transporter (PfCRT), multidrug resistance transporter

(PfMDR1), or sodium-proton exchanger (PfNHE).36–41

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Table 5. IC50 screen results for Cinchona alkaloid derivatives.

Entry Compound # HB3 (CQS) IC50 (nM) Dd2 (CQR) IC50 (nM) 1 QN 81 ± 8 320 ± 50 2 CD 70 ± 8 207 ± 11 3 QD 18 ± 2 90 ± 8 4 CN 22 ± 6 82 ± 8

5 QN-1 427 ± 4 485 ± 6

6 QN-2 428 ± 4 318 ± 2

7 QN-3 128 ± 5 184 ± 7 8 QN-4 > 500 > 500 9 CD-1 297 ± 13 223 ± 8 10 CD-2 590 ± 17 198 ± 5

11 CD-3 127 ± 4 176 ± 2 12 CD-4 394 ± 5 928 ± 6 13 QD-1 165 ± 5 2350 ± 4 14 QD-2 120 ± 6 203 ± 10

15 QD-3 123 ± 1 202 ± 7 16 QD-4 98 ± 3 182 ± 12 17 CN-1 66 ± 8 983 ± 2 18 CN-2 144 ± 1 263 ± 4 19 CN-3 90 ± 3 243 ± 2 20 CN-4 154 ± 1 146 ± 2 a IC50 values are an average of triplicate measurements and reported ± S.E.M. b Derivatives with low activity (>500 nM) were not quantified for IC50.

Activity for the QD, CN, and CD derivatives was, in most cases, improved relative to QN, but in general they were at best comparable to the parent drug. CN has the same absolute configuration as QD and is more active relative to CD, which has the same configuration as QN, similarly, QD is known to be more active than QN.37 These trends are reflected in the series of derivatives; however, CD compounds exhibited, on average, slightly improved activity over CN compounds vs. CQR strain Dd2 (Table 5).

For the amino QN series (Figure 12), nearly all compounds maintained greater than 50% growth at 10 μM. The same trend was seen for the amino eQN compounds

(Figure 13). Thus, full half maximal inhibitory concentration (IC50) binding curves were not sought for both sets as they all exhibited poor growth inhibitions against both strains

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over the concentration range tested. This further suggested that modifications at the 9- position hydroxyl is not well tolerated, as reported by the Roepe lab.21

Figure 12. Initial screening of the amino QN series in Dd2 and HB3. Error bars are standard deviations (n=3).

Surprisingly, the most potent compounds of the amino derivatives were found in the amino eQN series (Figure 13). In general, they were slightly more active in Dd2 than

HB3 and also compared to their counterparts in the amino QN set in both strains. In particular, 26, the para-trifluoromethyl benzamide, and 40, the benzyl amine, had IC50 values in the 1–10 μM range for both strains. This was unexpected because eQN, the

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parent compound, was reported to be 100 times less active than QN,27 which has the same absolute configuration as the amino QN series.

Figure 13. Initial screening of the amino eQN series in Dd2 and HB3. Error bars are standard deviations (n=3).

The propionamide (24) and the benzamide (25) in the amino eQN set yielded IC50 values above 10 μM. Other amide protections with various electron-withdrawing groups on the phenyl ring of a benzamide may provide an increase in activity as seen in 26.

Some future derivatives may contain a para-nitro, a di-nitro, and a bis-trifluoromethyl substituents. The carbamates (27 and 28), the tosyl protection (29), and the thiourea (30)

22

acted very similarly in the Dd2 strain by decreasing the percent growth to approximately

70% with 10 μM. With the lack of an available hydrogen on the 9-amino group, the phthalimide (38) worked as expected in both strains with over 100% growth, indicating little to no activity at every concentration tested. Lastly, the benzyl protected compound

(40) was the only derivative without an electron-withdrawing group on the amine; therefore, it may be beneficial to vary protections with more electron donating groups, such as a propyl or benzyl protections with methoxy and amino groups around the ring.

β-Hematin Crystal Growth Inhibition Data

A select set of the most active and least active compounds from the Cinchona alkaloid derivatives were screened for their ability to inhibit Hz formation in vitro at pH

5.2 and 5.6 (Table 6). The least active compounds, relative to QN, were QN-1, QN-4,

CD-4 and QN-5, which was from a previous series (Figure 14).23 Measurement at both pH 5.2 and 5.6 may mimic physiological conditions, since different digestive vacuole pH for sensitive (HB3) vs. resistant (Dd2) strains has been measured in some studies.43

Figure 14. Inactive compound, QN-5, from a previous series.23

23

Table 6. β-Hematin inhibitory IC50 data for select Cinchona alkaloids at pH 5.2 and 5.6. Entry Compound ID pH 5.2 IC50 (μM) pH 5.6 IC50 (μM) 1 QN 291 ± 1 34 ± 1 2 CQ 49 ± 1 33 ± 2 3 QD 130 ± 3 23 ± 2 4 CN 370 ± 12 170 ± 9 5 CD 321 ± 14 142 ± 11 6 *QN-1 100 ± 15 46 ± 2 7 QN-2 54 ± 4 40 ± 3 8 *QN-4 71 ± 3 52 ± 2 9 *QN-5 44 ± 5 23 ± 2 10 QD-2 81 ± 1 40 ± 0.2 11 CD-3 - 116 ± 1 12 *CD-4 75 ± 10 70 ± 9 13 CN-2 66 ± 10 50 ± 1 14 CN-4 63 ± 5 39 ± 4 a IC50 values are an average of three independent measurements and reported ± S.E.M. *Inactive compounds

All compounds except CD-3 (which did not achieve >50% Hz crystal growth inhibition over the course of the assay, despite several trials) exhibited Hz inhibition similar to QN at pH 5.2. Interestingly, derivatives that were either active or inactive in antiplasmodial growth inhibition assays were active inhibitors of Hz formation, similar to other trends observed recently with CQ derivatives.44 This can be seen by the cluster of compounds with fairly similar and low IC50 values (Figure 15).

The lack of correspondence with Hz inhibitory activity is perhaps supported by the fact that the quiniclidine alkene does not appear to play a role in complex formation, as found by the Roepe lab.21 That is, further derivatization at the alkene would not be expected to add to or alter Hz inhibition activity. These possibilities might also account for the lack of correlation between the two sets of IC50 values. Indeed, derivatives QD-2,

CD-3, and CN-4 exhibit significantly decreased Hz inhibition at pH 5.2 but improved antiplasmodial activity against Dd2. This may further suggest that alternative targets may be responsible or possibly a differential interaction with the same target.

24

It should also be noted that Hz inhibition occurs at drug concentrations closer to cytotoxic doses and not to the cytostatic dosages employed in the antiplasmodial screens.45 Perhaps Fe protoporphyrin IX (FPIX), a heme-like compound used in drug- heme interaction studies, is an important Cinchona alkaloid target at cytostatic concentrations, with an alternative mechanism of action relevant at cytocidal concentration. The fact that QN and CD are slightly poorer antimalarial drugs relative to

QD and CN (matched stereochemical pairs) but that CN and CD are poorer Hz inhibitors relative to QN and QD (matched constitutional isomeric pairs) supports this dose dependency. Additional experiments can address these points.

Figure 15. Plot of β-hematin inhibitory IC50 vs. antiplasmodial IC50. Black symbols correspond to BHIA IC50 at pH 5.6 and antiplasmodial IC50 against HB3. Gray symbols correspond to BHIA IC50 at pH 5.2 and antiplasmodial IC50 against Dd2. The IC50 value for QN at pH 5.2 is omitted for clarity. QN series derivatives that were not active antiplasmodial agents (and therefore do not have an antiplasmodial IC50) are also not included.

25

CONCLUSIONS & FUTURE WORK

Positive modifications on quinine from a previous series led to the study on the rest of the Cinchona alkaloids, CD, QD and CN. Thirteen new Cinchona alkaloid derivatives were synthesized, purified, and tested on HB3 (CQR) and Dd2 (CQS) strains of P. falciparum. In general, modifications with a para-substituted electron-withdrawing group yielded the best antiplasmodial results in comparison to the activity of QN.

Leading compounds were at best only comparable to their parent drugs. However, overall, the modifications were well-tolerated and yielded promising IC50 values.

Further studies on Hz inhibition demonstrated that derivatives that were either active or inactive in antiplasmodial growth were active inhibitors of Hz formation. This may possibly confirm that the quinuclidine alkene does not play a role in complex formation, as found by the Roepe lab.21 On the other hand, QD-2, CD-3, and CN-4 exhibited significantly decreased Hz inhibition at pH 5.2 but improved antiplasmodial activity against Dd2. Thus, alternative targets may be responsible or possibly a differential interaction with the same target. Future work with FPIX and toxicity studies will give more information about all of these compounds.

Twenty amino derivatives were synthesized with 2 configurations at carbon 9 of

QN, 9R and 9S. Compounds included amides, carbamates, a thiourea compound and protections with tosyl, phthalimide, and a benzyl group. All were poor antimalarial drug candidates with IC50 values in the μM range. Curiously, the most potent compounds were in the eQN amino series, 26 and 40. This was unexpected because eQN, the parent compound, has lower antimalarial activity than QN. Future compounds will include amides with electron-withdrawing groups on the phenyl ring (Figure 16) and protections

26

with electron-donating groups. Moreover, as we continue to consider the hydroxyl function on QN, it is possible that other hydrogen donating groups, such as a thiol or hydroxyl amine (Figure 17), may provide other routes to improved activity in CQS and

CQR strains.

Figure 16. Future protecting groups on amino eQN (21).

Figure 17. Derivatives with other hydrogen donating groups on carbon 9 of QN.

27

EXPERIMENTAL

General

1H NMR spectra were recorded on Bruker DRX (400 MHz). Chemical shifts are reported in ppm from tetramethylsilane with the solvent resonance as the internal standard (CDCl3: 7.27 ppm). Data are reported as follows: chemical shift, integration, multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, br = broad, m = multiplet), and coupling constants (Hz). 13C NMR spectra were recorded on a Bruker DRX 400

(100 MHz) spectrometer with complete proton decoupling. Chemical shifts are reported in ppm from tetramethylsilane with the solvent as the internal standard (CDCl3: 77.0 ppm).

Thin layer chromatography (TLC) was performed on EMD Chemicals 0.25 mm silica gel 60 plates. Visualization was achieved with UV light at 254 nm, potassium permanganate (KMnO4) stain, or 2,4-dinitrophenylhydrazine (DNPH) stain.

All reactions were conducted in oven and flame dried glassware under an inert atmosphere of argon. All solvents were EMD Chemicals anhydrous solvents sold by

VWR International. Each solvent was purged with Argon for a minimum of 15 minutes and stored over activated 3Å molecular sieves in sure-seal bottles. Quinine, quinidine, cinchonidine, cinchonine, 4-bromobenzotrifluoride, 3-bromobenzotrifluoride, ethyl-4- bromobenzoate, 3-bromofluorobenzene, diphenylphosphonic acid (DPPA), benzyl chloroformate, priopionyl chloride, p-toluenesulfonyl chloride, phthalic anhydride, and benzaldehyde were purchased from Alfa Aesar. Triethylamine was purchased from

Acros Chemical Company. Triphenylphosphine, palladium(II)acetate and sodium borohydride were purchased from Strem Chemical Company. Benzoyl isothiocyanate,

28

benzoyl chloride and diisopropyl azidocarboxylate (DIAD) were purchased from Sigma

Aldrich. Lastly, di-tert-butyl dicarbonate was purchased from Oakwood Products and 4-

(trifluoromethyl)benzoyl chloride was purchased from TCI America.

General Synthetic Method for Cinchona Alkaloid Vinyl Derivatives

Quinidine (81.1 mg, 0.25 mmol), palladium(II)acetate (2.8 mg, 0.0125 mmol), and triphenylphosphine (6.6 mg, 0.025 mmol) were all weighed out on the bench top and placed into a reaction vial. The indicated aryl bromide and dry toluene (1 mL, 9.4M) were added to the reaction vial by syringes. TEA (69.7 µL, 0.50 mmol) was added last, drop-wise, into the reaction vial via syringe. The reaction was placed under argon and stirred at 110°C for 24 hours. Contents were allowed to cool to room temperature, followed by filtration through a cotton plug unless otherwise specified. The solid was washed with DCM and the filtrate was concentrated under reduced pressure. The product was purified by silica gel flash column chromatography using gradient solvent systems of dichloromethane (DCM) and methanol (MeOH). TLC monitored the fractions for product. An olefin standard was spotted simultaneously with reaction contents to aid this process. Fractions containing product were combined and concentrated under reduced pressure to give a slightly yellow solid of a yield between 30.7–93.0%.

11-biphenyl-quinine (QN-3). 4-Bromobiphenyl (116.6 mg, 0.50 mmol) was used with

all other general synthesis conditions for Cinchona alkaloid

derivatives. The filtrate was concentrated under reduced pressure and

purified by silica gel flash column chromatography with a gradient

29

solvent system ranging from 5-15% MeOH in DCM to yield an average of 75.7 mg

-1 (62%). IR: 2931, 1621, 1508, 1241 cm . HRMS: Calculated for C32H32N2NaO2:

+ + 1 499.2356 (M+Na ), found 499.2351 (M+Na ). H-NMR (CDCl3): δ 8.73 ppm (1H, d, J

= 4.5), 7.93 (1H, d, J = 9.2), 7.61 (1H, d, J = 4.5), 7.55 (2H, m), 7.47 (2H, d, J = 8.3),

7.41 (2H, m), 7.31 (3H, m), 7.24 (1H, m), 7.12 (1H, s), 6.40 (1H, d, J = 15.6), 6.09 (1H, dd, J = 7.9, 15.6), 5.94 (1H, s), 3.81 (3H, s), 3.34 (2H, m), 2.87 (2H, m), 2.65 (1H, m),

1.98 (3H, m), 1.71 (1H, m), 1.57 (1H, m), 1.26 (1H, m), 0.87 (1H, m). 13C-NMR

(CDCl3): δ 157.82 ppm, 147.39, 146.42, 144.07, 140.54, 140.14, 135.76, 131.92, 131.53,

130.45, 128.74, 128.69, 127.22, 127.14, 126.90, 126.81, 126.41, 126.13, 125.99, 121.57,

118.47, 100.67, 60.12, 56.70, 55.68, 43.14, 38.77, 29.65, 28.05, 26.43, 23.79, 20.58.

11-(3-(trifluoromethyl)-phenyl)-quinine (QN-4). 3-Bromobenzotrifluoride (70.0 µL,

0.50 mmol) was used with all other general synthesis conditions and

reacted for 24 hours. The filtrate was concentrated under reduced

pressure and purified by silica gel flash column chromatography with

the solvent system of 92% DCM, and 8% MeOH to yield 0.071g

-1 (60%). IR: 2936, 1621, 1509, 1332 cm . HRMS: Calculated for C27H28F3N2O2:

+ + 1 469.2097 (M+H ), found 469.2099 (M+H ). H-NMR (CDCl3): δ 8.46 ppm (1H, d, J =

4.8 Hz), 7.87 (1H, d, J = 10), 7.51 (1H, d, J = 4.4), 7.47 (1H, s), 7.38 (3H, m), 7.25 (2H, m), 6.35 (1H, d, J = 15.6), 6.16 (1H, dd, J = 7.8, 15.8), 5.67 (1H, s), 3.86 (3H,s), 3.63

(1H, m), 3.20 (2H, m), 2.72 (2H, m), 2.49 (1H, m), 1.89 (3H, m), 1.56 (2H, m). 13C-

NMR (CDCl3): δ 157.78, 147.79, 147.26, 143.82, 137.84, 134.84, 131.18, 131.01,

130.69, 129.13, 128.92, 126.44, 123.71, 122.69, 121.47, 118.55, 101.31, 70.77, 60.21,

57.03, 55.81, 43.18, 39.31, 28.11, 27.07, 21.16.

30

11-(4-(trifluoromethyl)-phenyl)-cinchonidine (CD-1). 4-bromobenzotrifluoride (70.0

µL, 0.50 mmol) was used with all other general synthesis conditions for

Cinchona alkaloid derivatives except for the cotton filtration of the

crude product. The filtrate was concentrated under reduced pressure

and purified by silica gel flash column chromatography with a gradient solvent system ranging from 10-20% MeOH in DCM to yield an average of 57.6 mg

-1 (52%). IR: 2928, 1713, 1510, 1277 cm . HRMS: Calculated for C26H25F3N2NaO:

+ + 1 461.1811 (M+Na ), found 461.1809 (M+Na ). H-NMR (CDCl3): δ 8.82 ppm (1H, d, J =

4.4 Hz), 8.12 (1H, d, J = 8.5), 7.86 (2H, d, J = 8.4), 7.19 (2H, d, J = 8.5), 6.96 (1H, t, J =

7.7), 6.51 (1H, s), 6.40 (1H, d, J = 15.7), 5.97 (1H, dd, J = 7.6, 15.8), 5.36 (1H, s), 4.63

(1H, m), 4.31 (2H, m), 3.59 (1H, m), 3.47 (1H, m), 3.17 (2H, m), 2.92 (1H, m), 2.36 (1H,

13 m), 2.19 (2H, m), 1.94 (1H, m). C-NMR (CDCl3): δ 166.14 ppm, 149.60, 147.24,

145.70, 140.01, 131.94, 130.69, 129.97, 129.82, 129.72, 129.67, 128.84, 128.00, 127.01,

126.05, 124.00, 122.71, 118.70, 66.01, 60.97, 55.50, 44.32, 37.00, 27.48, 24.20, 18.27,

14.24.

11-(4-(ethylcarboxy)phenyl)-cinchonidine (CD-2). Ethyl 4-bromobenzoate (81.6 µL,

0.50 mmol) was used with all other general synthesis conditions for

Cinchona alkaloid derivatives. The filtrate was concentrated under

reduced pressure and purified by silica gel flash column

chromatography with a gradient solvent system ranging from 2.5-10%

MeOH in DCM to yield an average of 102.0 mg (93%). IR: 2924, 2590, 1326, 1122 cm-

1 + . HRMS: Calculated for C28H30N2NaO3: 465.2149 (M+Na ), found 465.2146

+ 1 (M+Na ). H-NMR (CDCl3): δ 8.82 ppm (1H, d, J = 4.5 Hz), 8.12 (1H, d, J = 8.4), 7.71

31

(3H, m), 7.44 (2H, d, J = 8.3), 7.23 (2H, d, J = 8.0), 6.96 (1H, t, J = 7.4), 6.52 (1H, s),

6.40 (1H, d, J = 15.7), 5.96 (1H, dd, J = 7.5, 15.8), 4.64 (1H, m), 3.59 (1H, m), 3.46 (1H, m), 3.18 (3H, m), 2.91 (1H, m), 2.35 (1H, m), 2.21 (2H, m), 1.93 (1H, m), 1.43 (1H, m).

13 C-NMR (CDCl3): δ 149.57 ppm, 147.14, 145.84, 139.15, 131.31, 130.90, 129.51,

128.85, 128.30, 127.00, 126.30, 125.45, 125.41, 125.38, 124.02, 122.76, 118.67, 65.99,

60.85, 55.34, 44.19, 36.81, 27.36, 24.11, 18.24, 11.29.

11-biphenyl-cinchonidine (CD-3). 4-Bromobiphenyl (116.6 mg, 0.50 mmol) was used

with all other general synthesis conditions for Cinchona alkaloid

derivatives. The filtrate was concentrated under reduced pressure and

purified by silica gel flash column chromatography with a gradient

solvent system ranging from 0-20% MeOH in DCM to yield an average of 60.4 mg (51%). IR: 2919, 1592, 1510, 1459 cm-1. HRMS: Calculated for

+ + 1 C31H30N2NaO: 469.2250 (M+Na ), found 469.2245 (M+Na ). H-NMR (CDCl3): δ 8.83 ppm (1H, d, J = 4.4 Hz), 8.13 (1H, d, J = 8.4), 7.72 (2H, m), 7.51 (2H, m), 7.42 (5H, m),

7.33 (1H, m), 7.21 (2H, d, J = 8.3), 6.99 (1H, t, J = 7.9), 6.51 (1H, s), 6.40 (1H, d, J =

15.8), 5.90 (1H, dd, J = 7.5, 15.8), 4.62 (1H, m), 3.59 (1H, m), 3.46 (1H, m), 3.16 (3H, m), 2.91 (1H, m), 2.35 (1H, m), 2.19 (2H, m), 1.94 (1H, m), 1.46 (1H, m). 13C-NMR

(CDCl3): δ 149.64 ppm, 147.27, 145.92, 140.69, 140.33, 138.80, 132.19, 129.65, 128.88,

128.46, 128.30, 127.40, 127.07, 129.96, 124.10, 122.80, 118.74, 66.10, 61.01, 55.72,

44.31, 36.95,m 27.59, 24.26, 18.30.

11-(3-(trifluoromethyl)-phenyl)-cinchonidine (CD-4). 3-Bromobenzotrifluoride (70.0

µL, 0.50 mmol) was used with all other general synthesis conditions for

Cinchona alkaloid derivatives. The filtrate was concentrated under

32

reduced pressure and purified by silica gel flash column chromatography with a gradient solvent system ranging from 0-5% MeOH in DCM to yield an average of 70.2 mg (64%).

-1 IR: 3278, 2923, 1332, 1124 cm . HRMS: Calculated for C26H25F3N2NaO: 461.1811

+ + 1 (M+Na ), found 461.1816 (M+Na ). H-NMR (CDCl3): δ 8.82 ppm (1H, d, J = 4.5 Hz),

8.11 (1H, d, J = 8.4), 7.71 (3H, m), 7.39 (2H, m), 7.30 (2H, m), 6.95 (1H, t, J = 8.0), 6.49

(1H, s), 6.40 (1H, d, J = 15.4), 5.94 (1H, dd, J = 7.4, 15.9), 5.42 (1H, m), 4.63 (1H, m),

3.59 (1H, m), 3.47 (1H, m), 3.16 (3H, m), 2.92 (1H, m), 2.36 (1H, m), 2.21 (2H, m), 1.95

13 (1H, m), 1.42 (1H, m). C-NMR (CDCl3): δ 149.60 ppm, 147.22, 145.76, 136.51,

131.29, 130.22, 129.62, 129.29, 129.01, 128.81, 126.96, 124.46, 124.42, 124.00, 122.84,

122.80, 122.68, 118.67, 66.11, 60.91, 55.43, 44.27, 36.91, 27.44, 24.24, 18.33.

11-(4-(trifluoromethyl)-phenyl)-quinidine (QD-1). 4-bromobenzotrifluoride (140.0

µL, 1.0 mmol) was used with all other general synthesis conditions for

Cinchona alkaloid derivatives. The filtrate was concentrated under

reduced pressure and purified by silica gel flash column chromatography with a gradient solvent system ranging from 10-25% MeOH in DCM to yield an average of 57.1 mg (49%). IR: 2924, 1619, 1508, 1241 cm-1. HRMS: Calculated for

+ + 1 C27H27F3N2NaO2: 491.1917 (M+Na ), found 491.1912 (M+Na ). H-NMR (CDCl3): δ

8.72 ppm (1H, d, J = 4.5 Hz), 7.74 (2H, m), 7.62 (3H, m), 7.52 (2H, m), 7.45 (1H, m),

7.02 (1H, dd, J = 3.0, 9.2), 6.91 (1H, d, J = 2.5), 6.73 (1H, s), 6.63 (1H, d, J = 15.9), 6.54

(1H, dd, J = 7.5, 15.9), 4.59 (1H, m), 3.59 (3H, s), 3.42 (4H, m), 3.17 (1H, m), 2.81 (1H,

13 m), 2.54 (1H, m), 1.98 (1H, m), 1.26 (1H, m), 1.08 (1H, m). C-NMR (CDCl3): δ

157.30 ppm, 146.92, 143.99, 143.55, 139.84, 132.49, 132.02, 131.98, 131.92, 131.78,

33

131.46, 131.15, 130.30, 128.69, 128.57, 128.45, 126.66, 125.63, 125.60, 125.47, 125.27,

122.54, 118.77, 99.73, 66.36, 60.06, 57.38, 49.39, 48.67, 37.13, 28.01, 23.25, 18.01.

11-(4-(ethylcarboxy)phenyl)-quinidine (QD-2). Ethyl 4-bromobenzoate (81.6 µL, 0.50

mmol) was used with all other general synthesis conditions for

Cinchona alkaloid derivatives except for the cotton filtration of the

crude product. The filtrate was concentrated under reduced pressure

and purified by silica gel flash column chromatography with the solvent system of 5% MeOH in DCM to yield an average of 99.6 mg (84%). IR: 2929,

-1 + 1713, 1508, 1241 cm . HRMS: Calculated for C29H32N2NaO4: 495.2254 (M+Na ),

+ 1 found 495.2250 (M+Na ). H-NMR (CDCl3): δ 8.72 ppm (1H, d, J = 4.5 Hz), 8.04 (2H, d, J = 8.4), 7.76 (2H, m), 7.50 (1H, d, J = 8.4), 7.02 (1H, dd, J = 2.4, 9.2), 6.92 (1H, d,

2.5), 6.73 (1H, s), 6.63 (1H, d, J = 16.0), 6.55 (1H, dd, J = 7.3, 15.9), 4.60 (1H, m), 4.41

(2H, m), 3.56 (3H, s), 3.41 (3H, m), 3.17 (1H, m), 2.81 (1H, m), 2.55 (1H, m), 2.10 (1H,

13 s), 1.97 (2H, m), 1.73 (2H, m), 1.43 (3H, t, J = 7.1), 1.07 (1H, m). C-NMR (CDCl3): δ

166.36 ppm, 158.31, 146.95, 143.81, 143.64, 140.64, 132.33, 131.23, 130.06, 129.98,

129.70, 129.34, 128.29, 126.34, 125.25, 122.58, 118.77, 99.64, 66.40, 61.01, 60.07,

57.41, 49.41, 48.75, 37.28, 35.22, 28.06, 25.15, 24.31, 23.70, 23.27, 18.05, 14.34.

11-biphenyl-quinidine (QD-3). 4-bromobiphenyl (116.6 mg, 0.50 mmol) was used with

all other general synthesis conditions for Cinchona alkaloid

derivatives. The filtrate was concentrated under reduced pressure and

purified by silica gel flash column chromatography with a gradient

solvent system ranging from 8-20% MeOH in DCM to yield an average of 36.6 mg (31%). IR: 2924, 1618, 1506, 1240 cm-1. HRMS: Calculated for

34

+ + 1 C32H32N2NaO2: 499.2356 (M+Na ), found 499.2351 (M+Na ). H-NMR (CDCl3): δ 8.75 ppm (1H, d, J = 4.5 Hz), 7.82 (1H, d, J = 9.2), 7.75 (1H, d, J = 4.6), 7.63 (3H, m), 7.47

(4H, m), 7.38 (2H, m), 7.10 (1H, dd, J = 2.4, 9.1), 7.02 (1H, d, J = 2.5), 6.71 (1H, s), 6.61

(1H, d, J = 16.0), 6.48 (1H, dd, J = 7.8, 15.9), 3.68 (3H, s), 3.37 (4H, m), 3.16 (1H, m),

2.78 (1H, m), 2.54 (1H, m), 1.98 (2H, m), 1.75 (2H, m), 1.07 (1H, m). 13C-NMR

(CDCl3): δ 158.18 ppm, 147.09, 144.23, 143.76, 140.61, 140.55, 135.48, 132.34, 131.34,

128.80, 128.66, 127.92, 127.38, 127.32, 126.92, 126.84, 126.40, 125.35, 122.27, 118.71,

99.83, 66.66, 59.98, 56.94, 49.26, 48.83, 37.41, 29.66, 28.24, 23.53, 18.18.

11-(3-(trifluoromethyl)-phenyl)-quinidine (QD-4). 3-Bromobenzotrifluoride (70.0 µL,

0.50 mmol) was used with all other general synthesis conditions for

Cinchona alkaloid derivatives. The filtrate was concentrated under

reduced pressure and purified by silica gel flash column

chromatography with a gradient solvent system ranging from 2-10%

MeOH in DCM to yield an average of 79.9 mg (66%). IR: 2925, 1621, 1509, 1242 cm-1.

+ + HRMS: Calculated for C27H27F3N2NaO2: 491.1917 (M+Na ), found 491.1912 (M+Na ).

1 H-NMR (CDCl3): δ 8.72 ppm (1H, d, J = 4.5 Hz), 7.76 (2H, m), 7.66 (2H, m), 7.51 (2H, m), 7.01 (1H, dd, J = 2.6, 9.2), 6.91 (1H, d, J = 2.4), 6.73 (1H, s), 6.62 (1H, d, J = 15.9),

6.50 (1H, dd, J = 7.7, 15.9), 5.59 (1H, s), 4.60 (1H, m), 3.56 (3H, s), 3.42 (4H, m), 3.17

13 (1H, m), 2.81 (1H, m), 2.53 (1H, m), 2.09 (1H, s), 1.98 (1H, m). C-NMR (CDCl3): δ

158.25 ppm, 146.92, 143.89, 143.53, 137.10, 131.70, 131.11, 130.79, 129.51, 129.41,

129.13, 125.35, 125.22, 124.42, 123.16, 123.12, 122.64, 122.48, 118.72, 99.70, 66.32,

60.02, 57.32, 49.34, 48.62, 37.07, 27.95, 23.20, 17.99, 11.48.

35

11-(4-(trifluoromethyl)-phenyl)-cinchonine (CN-1). 4-bromobenzotrifluoride (70.0

µL, 0.50 mmol) was used with all other general synthesis conditions

and for Cinchona alkaloid derivatives except for the cotton filtration of

the crude product. The filtrate was concentrated under reduced

pressure and purified by silica gel flash column chromatography with a gradient solvent system ranging from 5-20% MeOH in DCM to yield an average of 60.2

-1 mg (55%). IR: 2930, 2590, 1325, 1121 cm . HRMS: Calculated for C26H25F3N2NaO:

+ + 1 461.1811 (M+Na ), found 461.1809 (M+Na ). H-NMR (CDCl3): δ 8.84 ppm (1H, d, J =

4.5 Hz), 8.02 (1H, d, J = 8.1), 7.76 (3H, m), 7.63 (2H, m), 7.56 (2H, m), 7.01 (1H, m),

6.72 (1H, s), 6.64 (1H, d, J = 16.0), 6.56 (1H, dd, J = 7.4, 16.0), 4.60 (1H, m), 3.49 (3H, m), 3.38 (2H, m), 3.21 (1H, m), 2.83 (1H, m), 2.54 (1H, m), 2.09 (1H, s), 1.97 (1H, m),

13 1.07 (1H, m). C-NMR (CDCl3): δ 149.71 ppm, 147.35, 145.48, 138.81, 131.80, 130.26,

129.71, 128.95, 128.72, 127.12, 126.66, 125.64, 125.60, 124.05, 122.46, 118.56, 66.38,

50.64, 49.59, 48.86, 37.13, 27.95, 23.28, 18.00, 11.53.

11-(4-(ethylcarboxy)phenyl)-cinchonine (CN-2). Ethyl 4-bromobenzoate (81.6 µL,

0.50 mmol) was used with all other general synthesis conditions for

Cinchona alkaloid derivatives except for the cotton filtration of the

crude product. The filtrate was concentrated under reduced pressure

and purified by silica gel flash column chromatography with a gradient solvent system ranging from 5-20% MeOH in DCM to yield an average of 71.7

-1 mg (65%). IR: 2932, 1607, 1510, 1278 cm . HRMS: Calculated for C28H30N2NaO3:

+ + 1 465.2149 (M+Na ), found 465.2144 (M+Na ). H-NMR (CDCl3): δ 8.86 ppm (1H, d, J =

4.4 Hz), 8.05 (3H, d, J = 8.2), 7.82 (1H, d, J = 8.5), 7.76 (1H, d, J = 4.4), 7.51 (2H, d, J =

36

8.2), 7.34 (1H, m), 7.07 (1H, m), 6.77 (1H, s), 6.63 (1H, d, J = 16.0), 6.56 (1H, dd, J =

7.2, 15.6), 5.31 (1H, s), 4.58 (1H, m), 4.41 (2H, m), 3.47 (3H, m), 3.19 (1H, m), 2.84

(1H, m), 2.54 (1H, m), 2.10 (1H, m), 1.99 (1H, m), 1.43 (3H, t, J = 7.2), 1.26 (1H, s),

13 1.09 (1H, m). C-NMR (CDCl3): δ 166.37 ppm, 149.76, 147.44, 145.51, 140.69, 132.29,

132.07, 131.97, 130.17, 129.99, 129.78, 129.69, 129.01, 128.56, 128.44, 127.19, 126.47,

126.34, 124.14, 122.56, 118.61, 66.49, 61.02, 60.65, 49.60, 48.93, 37.30, 28.02, 24.29,

23.34, 18.08, 14.35.

11-biphenyl-cinchonine (CN-3). 4-Bromobiphenyl (116.6 mg, 0.50 mmol) was used

with all other general synthesis conditions for Cinchona alkaloid

derivatives. The filtrate was concentrated under reduced pressure and

purified by silica gel flash column chromatography with a gradient

solvent system ranging from 0-5% MeOH in DCM to yield an average of 47.5 mg (42%). IR: 2923, 1620, 1510, 1486 cm-1. HRMS: Calculated for

+ + 1 C31H30N2NaO: 469.2250 (M+Na ), found 469.2245 (M+Na ). H-NMR (CDCl3): δ 8.88 ppm (1H, d, J = 4.4 Hz), 8.06 (1H, m), 7.85 (1H, m), 7.77 (1H, d, J = 4.5), 7.64 (3H, m),

7.58 (1H, m), 7.53 (1H, m), 7.46 (3H, m), 7.38 (3H, m), 7.09 (1H, m), 6.74 (1H, s), 6.62

(1H, d, J = 15.7), 6.47 (1H, dd, J = 7.7, 15.7), 4.52 (1H, m), 3.47 (3H, m), 3.36 (2H, m),

3.17 (1H, m), 2.79 (1H, m), 2.54 (1H, m), 2.08 (1H, s), 1.98 (1H, m), 1.08 (1H, m). 13C-

NMR (CDCl3): δ 149.74 ppm, 147.35, 145.82, 140.55, 140.50, 135.43, 132.40, 129.63,

128.94, 128.77, 128.73, 128.70, 128.63, 127.78, 127.32, 127.29, 127.147, 127.07, 127.01,

126.94, 126.88, 126.85, 126.40, 124.18, 122.59, 118.60, 66.58, 66.34, 60.55, 49.56,

49.06, 37.25, 28.11, 23.35, 18.05, 11.52.

37

11-(3-(trifluoromethyl)-phenyl)-cinchonine (CN-4). 3-Bromobenzotrifluoride (70.0

µL, 0.50 mmol) was used with all other general synthesis conditions for

Cinchona alkaloid derivatives. The filtrate was concentrated under

reduced pressure and purified by silica gel flash column chromatography with a gradient solvent system ranging from 2-10% MeOH in DCM to yield an average of 47.7 mg (43%). IR: 2922, 2586, 1331, 1124 cm-1. HRMS: Calculated for

+ + 1 C26H25F3N2NaO: 461.1811 (M+Na ), found 461.1809 (M+Na ). H-NMR (CDCl3): δ

8.86 ppm (1H, d, J = 4.5 Hz), 7.76 (2H, m), 7.67 (2H, m), 7.54 (2H, m), 7.34 (1H, t, J =

7.7), 7.05 (1H, m), 6.74 (1H, s), 6.63 (1H, d, J = 16.0), 6.51 (1H, dd, J = 7.6, 15.8), 4.58

(1H, m), 3.49 (2H, m), 3.39 (1H, m), 3.19 (1H, m), 2.82 (1H, m), 2.53 (1H, m), 2.09 (1H,

13 s), 1.98 (2H, m), 1.72 (1H ,m), 1.08 (1H, m). C-NMR (CDCl3): δ 149.72 ppm, 147.38,

145.59, 137.18, 131.86, 131.73, 131.20, 130.88, 129.70, 129.56, 129.51, 129.17, 128.97,

127.17, 124.41, 124.15, 123.19, 123.15, 122.55, 118.60, 66.41, 60.65, 49.56, 48.84,

37.10, 33.19, 31.69, 27.96, 23.56, 18.04.

Synthetic Method for epi-quinine epi-quinine (eQN, 20). Quinine (3.24 g, 10 mmol) was dissolved in dry THF (40 mL) in

a flame-dried flask. Under argon, triethylamine (3.35 mL, 24 mmol) and

methanesulfonyl chloride (1.7 mL, 22 mmol) were added to the reaction and

stirred overnight at room temperature. The crude product was concentrated under reduced pressure and purified by silica gel flash column chromatography with 92:8

DCM/MeOH to yield a yellow solid of 3.26 g (81%). The mesylated quinine was further reacted with tartaric acid (1.1 equiv.) in water at reflux for 2h. After the reaction cooled

38

to room temperature, excess solid NaOH was added and a precipitate formed. The product was filtered, dissolved in DCM, dried over MgSO4, filtered once more, and concentrated. Silica gel flash column chromatography with a gradient solvent system of

20-50% MeOH in DCM and 50:50:1 EtOAc/MeOH/NH4OH yielded the product as a yellow solid (2.24 g, 69%). IR: 3271, 2937, 1620, 1239 cm-1. HRMS: Calculated for

+ + 1 C20H24N2NaO2: 347.1730 (M+Na ), found 347.1730 (M+Na ). H-NMR (CDCl3): δ

8.74 ppm (1H, d, J = 4.4 Hz), 8.03 (1H, d, J = 9.2), 7.65 (1H, d, J = 2.4), 7.39 (2H, m),

5.75 (1H, m), 5.01 (2H, m), 3.95 (3H, s), 3.23 (3H, m), 2.78 (2H, m), 2.33 (1H, m), 1.74

13 (1H, m), 1.62 (2H, m), 1.47 (1H, m), 0.98 (1H, m). C-NMR (CDCl3): δ 157.44 ppm,

147.57, 144.84, 144.29, 141.32, 131.63, 128.14, 121.29, 120.09, 114.68, 102.61, 71.35,

61.53, 55.90, 55.48, 40.74, 39.85, 27.94, 27.24, 25.12.

Synthetic Method for 21 and 22

9-amino-(9-deoxy)-epi-quinine (21). Quinine (6.13 mmol) and triphenylphosphine

(1.95 g, 7.35 mmol) were dissolved in dry THF (30 mL) and cooled to 0°C.

DIAD (1.52 mL, 7.35 mmol) was added in one portion, then a solution of

DPPA (1.63 mL, 7.35 mmol) in dry THF (15 mL) was added dropwise at

0°C. After the mixture was warmed to room temperature and stirred overnight, the reaction was heated to 50°C for 2h. Triphenylphosphine (2.06 g, 7.97 mmol) was then added and heating was maintained until the gas evolution had ceased (2h). At room temperature, water (0.7 mL) was added and the solution was stirred for 3h. Solvents were removed under reduced pressure and the residue was dissolved in DCM (30 mL) and diluted hydrochloric acid (10%, 30 mL). The aqueous phase was washed with DCM

39

(3 x 30 mL), alkalinized with an excess of concentrated ammonium hydroxide, and washed again with DCM (3 x 30 mL). The last organic layer was dried over MgSO4 and concentrated. Silica gel flash column chromatography with a gradient solvent system of

20-50% MeOH in DCM and 50:50:1 EtOAc/MeOH/NH4OH yielded a yellow solid (1.21

-1 g, 61%). IR: 3316, 2934, 1641, 1240 cm . HRMS: Calculated for C20H25N3NaO:

+ + 1 346.1890 (M+Na ), found 346.1890 (M+Na ). H-NMR (CDCl3): δ 8.75 ppm (1H, d, J =

4.5 Hz), 8.03 (1H, d, J = 9.2), 7.65 (1H, br), 7.46 (1H, d, J = 3.1), 7.39 (1H, dd, J = 2.7,

9.2), 5.79 (1H, m), 5.00 (2H, m), 4.60 (1H, br), 3.97 (3H, s), 3.29 (1H, dd, J = 13.8,

10.1), 3.22 (1H, m), 3.09 (1H, m), 2.81 (2H, m), 2.29 (1H, m), 2.10 (2H, br), 1.63 (1H,

13 m), 1.55 (2H, m), 1.43 (1H ,m), 0.77 (1H, m). C-NMR (CDCl3): δ 157.39 ppm, 147.61,

144.50, 141.53, 131.55, 128.54, 121.05, 114.14, 56.06, 55.32, 53.28, 40.74, 39.57, 27.93,

27.33, 25.79.

9-amino-(9-deoxy)quinine (22). epi-Quinine (6.13 mmol) was used in the same

conditions reported above for 21 and purified by the same gradient solvent

system. This yielded a yellow solid of 0.93 g (47%). IR: 3285, 2938, 1621,

-1 + 1175 cm . HRMS: Calculated for C20H26N3O: 324.2070 (M+H ), found

+ 1 324.2070 (M+H ). H-NMR (CDCl3): δ 8.72 ppm (1H, d, J = 4.5 Hz), 7.99 (1H, d, J =

9.2), 7.43 (1H, d, J = 2.4), 7.35 (2H, m), 7.19 (1H, m), 5.91 (1H, m), 5.04 (2H, m), 4.66

(1H, d, J = 8.7), 3.95 (3H, s), 3.19 (1H, m), 3.04 (2H, m), 2.67 (1H, m), 2.56 (1H, m),

2.28 (1H, br), 2.11 (1H, m), 1.89 (1H, br), 1.68 (1H, m), 1.52 (2H ,m). 13C-NMR

(CDCl3): δ 157.69 ppm, 149.04, 147.81, 144.71, 141.62, 131.86, 128.89, 128.08, 127.52,

125.15, 121.10, 118.20, 114.47, 101.09, 60.49, 56.08, 55.60, 53.51, 41.91, 39.53, 27.66,

27.63, 26.16, 21.33.

40

General Synthetic Method of Protected 9-amino-(9-deoxy)quinine Derivatives

The appropriate 9-amino-(9-deoxy)-epi-quinine (21) or 9-amino-(9-deoxy)quinine

(22) (0.25 mmol) was dissolved in dry toluene (1 mL) and cooled to 0°C. Triethylamine

(1.2 equiv.) and the protecting group (1.05 equiv.) were added. The reaction was allowed to warm to room temperature and stirred overnight. The product was concentrated in vacuo and purified by silica gel flash column chromatography to afford the title compounds.

9-(priopionyl)amino-(9-deoxy)-epi-quinine (24). Propionyl chloride (23.2 µL, 0.26

mmol) was used with all other general synthesis conditions for the amino

derivatives. The product was purified by silica gel flash column

chromatography with 92:8 DCM/MeOH to yield an average of 91.1 mg

-1 (96%). IR: 3321, 2926, 1648, 1229 cm . HRMS: Calculated for C23H29N3NaO2:

+ + 1 402.2152 (M+Na ), found 402.2152 (M+Na ). H-NMR (CDCl3): δ 8.68 ppm (1H, d, J =

4.5 Hz), 7.96 (1H, d, J = 9.2), 7.80 (1H, br), 7.65 (1H, d, J = 2.04), 7.45 (1H, d, J = 2.0),

7.33 (1H, dd, J = 2.5, 9.2), 5.71 (2H, m), 5.05 (2H, m), 3.95 (3H, s), 3.88 (1H, m), 3.51

(2H, m), 3.00 (2H, m), 2.49 (1H, m), 2.35 (1H, m), 2.17 (1H, m), 1.81 (3H, m), 1.69 (1H,

13 m), 1.02 (4H, t, J = 7.5). C-NMR (CDCl3): δ 174.29 ppm, 158.12, 147.42, 144.61,

143.02, 138.48, 131.56, 128.02, 122.02, 116.19, 101.46, 55.72, 54.71, 53.34, 45.70,

41.10, 37.68, 29.28, 26.89, 25.71, 25.26, 9.26.

9-(benzoyl)amino-(9-deoxy)-epi-quinine (25). Benzoyl chloride (30.5 µL, 0.26 mmol)

was used with all other general synthesis conditions for the amino

derivatives. The product was purified by silica gel flash column

41

chromatography with 92:8 DCM/MeOH to yield an average of 84.4 mg (79%). IR:

-1 + 3321, 2926, 1621, 1229 cm . HRMS: Calculated for C27H30N3O2: 428.2333 (M+H ),

+ 1 found 428.2333 (M+H ). H-NMR (CDCl3): δ 8.72 ppm (1H, d, J = 4.5 Hz), 8.20 (1H, br), 8.02 (1H, d, J = 9.2), 7.79 (1H, m), 7.48 (1H, d, J = 4.5), 7.40 (2H, m), 7.32 (2H, m),

5.72 (1H, m), 4.99 (2H, m), 4.48 (1H, br), 4.00 (3H, s), 3.46 (1H, m), 3.32 (2H, m), 2.80

13 (2H, m), 2.36 (1H, m), 1.71 (3H, m), 1.54 (1H, m), 1.07 (1H ,m). C-NMR (CDCl3): δ

174.56 ppm, 167.22, 157.86, 147.49, 144.68, 140.32, 133.61, 131.68, 131.52, 129.23,

128.34, 127.63, 127.12, 121.66, 115.07, 101.77, 55.63, 40.75, 38.90, 27.22, 27.17, 25.79.

9-((4-trifluoromethyl)-benzoyl)amino-(9-deoxy)-epi-quinine (26).

4-(Trifluoromethyl)benzoyl chloride (38.6 µL, 0.26 mmol) was used

with all other general synthesis conditions for the amino derivatives.

The product was purified by silica gel flash column chromatography with 92:8 DCM/MeOH to yield an average of 106.5 mg (86%). IR: 3239, 2940, 1654,

-1 + 1326 cm . HRMS: Calculated for C28H29F3N3O2: 496.2206 (M+H ), found 496.2206

+ 1 (M+H ). H-NMR (CDCl3): δ 8.79 ppm (1H, br), 8.72 (1H, d, J = 4.5 Hz), 8.01 (1H, d, J

= 9.2), 7.92 (2H, d, J = 8.1), 7.75 (1H, d, J = 2.4), 7.51 (3H, m), 7.38 (1H, m), 6.48 (1H, br), 5.71 (1H, m), 5.05 (2H, m), 3.99 (3H, s), 3.81 (1H, m), 3.44 (1H, m), 3.35 (1H, m),

13 2.92 (2H, m), 2.46 (1H, s), 1.79 (3H, m), 1.66 (1H ,m), 1.11 (1H, m). C-NMR (CDCl3):

δ 173.18 ppm, 166.15, 158.16, 147.46, 144.71, 138.97, 136.68, 133.19, 132.87, 131.77,

129.18, 128.09, 125.25, 125.22, 124.55, 124.51, 121.89, 115.93, 101.54, 55.72, 54.79,

40.89, 38.04, 26.95, 26.25, 25.37.

9-(benzylcarbamoyl)-(9-deoxy)-epi-quinine (27). Benzyl chloroformate (39.1 µL, 0.26

mmol) was used with all other general synthesis conditions for the

42

amino derivatives. The product was purified by silica gel flash column chromatography with 92:8 DCM/MeOH to yield an average of 78.9 mg (69%). IR: 3326, 2935, 1710,

-1 + 1243 cm . HRMS: Calculated for C28H32N3O3: 458.2438 (M+H ), found 458.2438

+ 1 (M+H ). H-NMR (CDCl3): δ 8.72 ppm (1H, d, J = 4.2 Hz), 8.03 (1H, d, J = 9.2), 7.64

(1H, br), 7.36 (3H, m), 7.27 (4H, m), 6.44 (1H, br), 5.69 (1H, m), 4.94 (4H, m), 3.91 (4H, br), 3.24 (1H, m), 3.14 (2H, m), 2.71 (2H, m), 2.27 (1H, m), 1.61 (3H, m), 1.40 (1H, m),

13 0.89 (1H, m). C-NMR (CDCl3): δ 157.69 ppm, 156.04, 147.48, 144.62, 141.14, 131.69,

128.33, 127.84, 127.21, 126.81, 121.51, 114.55, 101.55, 66.67, 64.72, 55.80, 55.45,

53.40, 40.78, 39.39, 27.79, 25.95.

9-(t-butylcarbamoyl)-(9-deoxy)-epi-quinine (28). Di-tert-butyl dicarbonate (56.7 mg,

0.26 mmol) was used with all other general synthesis conditions for the

amino derivatives. The product was purified by silica gel flash column

chromatography with 92:8 DCM/MeOH to yield an average of 97.4 mg

-1 (92%). IR: 3362, 2938, 1702, 1169 cm . HRMS: Calculated for C25H34N3O3:

+ + 1 424.2595 (M+H ), found 424.2595 (M+H ). H-NMR (CDCl3): δ 8.71 ppm (1H, d, J =

4.5 Hz), 8.01 (1H, d, J = 9.2), 7.62 (1H, br), 5.67 (1H, m), 4.91 (2H, m), 3.94 (3H, s),

3.71 (1H, m), 3.23 (1H, dd, J = 10.2, 13.8), 3.15 (1H, br), 2.99 (1H, br), 2.72 (1H, m),

2.65 (1H, m), 2.25 (1H, m), 1.81 (1H, m), 1.59 (2H, m), 1.33 (9H, br), 0.92 (2H, dd, J =

13 6.7, 13.7). C-NMR (CDCl3): δ 157.52 ppm, 155.41, 147.51, 145.70, 141.21, 131.68,

121.31, 119.06, 114.42, 101.72, 79.42, 67.84, 55.86, 55.49, 53.34, 40.77, 39.48, 28.10,

27.87, 27.27, 25.49.

9-(p-toluenesulfonyl)amino-(9-deoxy)-epi-quinine (29). p-Toluenesulfonyl chloride

(49.6 mg, 0.26 mmol) was used with all other general synthesis

43

conditions for the amino derivatives. The product was purified by silica gel flash column chromatography with 92:8 DCM/MeOH to yield an average of 74.0 mg (62%). IR:

-1 + 3209, 2944, 1621, 1165 cm . HRMS: Calculated for C27H32N3O3S: 478.2159 (M+H ),

+ 1 found 478.2159 (M+H ). H-NMR (CDCl3): δ 8.59 ppm (1H, d, J = 4.3 Hz), 8.50 (1H, d, J = 4.6), 7.96 (1H, d, J = 9.2), 7.82 (1H, d, J = 9.2), 7.53 (1H, d, J = 2.6), 7.37 (1H, dd,

J = 2.5, 9.2), 7.33 (3H, m), 7.28 (1H, m), 7.19 (3H, m), 6.95 (2H, d, J = 8.0), 6.70 (1H, d,

J = 8.1), 5.59 (2H, m), 4.88 (4H, m), 4.29 (1H, d, J = 10.8), 3.95 (3H, s), 3.83 (2H, s),

3.30 (1H, m), 3.18 (2H, m), 2.75 (3H, m), 2.63 (4H, m), 2.28 (3H, s), 2.23 (2H, br), 2.12

(2H, s), 1.65 (1H, br), 1.49 (5H, m), 1.23 (2H, m), 0.88 (1H, m), 0.80 (1H, m). 13C-NMR

(CDCl3): δ 157.81 ppm, 156.65, 147.34, 146.64, 144.87, 144.24, 143.28, 142.88, 142.83,

141.12, 140.86, 139.26, 136.30, 135.67, 131.70, 131.33, 128.80, 128.53, 128.21, 127.27,

126.93, 126.83, 123.97, 121.27, 121.04, 120.37, 114.67, 114.62, 103.05, 100.72, 62.57,

61.28, 56.08, 55.82, 55.49, 55.42, 55.35, 52.52, 40.18, 39.77, 39.57, 39.30, 27.75, 27.59,

27.28, 27.17, 26.10, 24.82, 21.33, 21.10.

9-(benzoylthiourea)-(9-deoxy)-epi-quinine (30). Benzoyl isothiocyanate (36.0 μL, 0.26

mmol) was used with all other general synthesis conditions for the

amino derivatives. The product was purified by silica gel flash column

chromatography with a gradient solvent system of 1-2% MeOH in DCM to yield an average of 103.4 mg (85%). IR: 3229, 2934, 1672, 1227 cm-1. HRMS:

+ + 1 Calculated for C28H31N4O2S: 487.2162 (M+H ), found 487.2162 (M+H ). H-NMR

(CDCl3): δ 11.50 ppm (1H, br), 9.07 (1H, br), 8.75 (1H, d, J = 4.6 Hz), 8.02 (1H, d, J =

9.2), 7.79 (2H, m), 7.74 (1H, br), 7.56 (1H, m), 7.43 (4H, m), 5.73 (1H, m), 4.96 (2H, m),

3.99 (3H, s), 3.33 (3H, m), 2.80 (2H, m), 2.29 (1H, m), 1.65 (3H, m), 1.41 (1H, m), 1.25

44

13 (1H, m), 0.97 (1H ,m). C-NMR (CDCl3): δ 179.19 ppm, 166.77, 157.81, 147.51,

144.76, 141.34, 133.40, 131.75, 128.95, 127.47, 121.95, 114.51, 102.00, 55.91, 55.69,

53.43, 41.43, 39.44, 31.52, 27.93, 27.33, 25.99, 14.09.

9-(priopionyl)amino-(9-deoxy)quinine (31). Propionyl chloride (23.2 µL, 0.26 mmol)

was used with all other general synthesis conditions for the amino

derivatives. The product was purified by silica gel flash column

chromatography with 92:8 DCM/MeOH to yield an average of 68.3 mg

-1 (72%). IR: 3272, 2939, 1667, 1229 cm . HRMS: Calculated for C20H29N3NaO2:

+ + 1 402.2152 (M+Na ), found 402.2152 (M+Na ). H-NMR (CDCl3): δ 8.67 ppm (1H, d, J =

4.6 Hz), 7.94 (1H, d, J = 9.2), 7.61 (1H, d, J = 2.6), 7.33 (2H, m), 5.97 (2H, m), 5.82 (1H, d, J = 9.4), 5.10 (2H, m), 3.96 (3H, s), 3.38 (1H, m), 3.12 (1H, m), 2.88 (1H, m), 2.77

(1H, m), 2.54 (1H, m), 2.31 (1H, m), 2.14 (2H, m), 2.02 (1H, m), 1.87 (1H, m), 1.75 (1H,

13 m), 1.51 (2H, m), 1.10 (3H, t, J = 7.6). C-NMR (CDCl3): δ 173.47 ppm, 158.07,

147.29, 144.63, 144.49, 141.82, 131.22, 128.37, 122.14, 119.03, 114.41, 101.45, 57.40,

55.72, 55.69, 49.10, 41.28, 39.38, 29.62, 27.43, 27.37, 25.23, 9.86.

9-(benzoyl)amino-(9-deoxy)quinine (32). Benzoyl chloride (30.5 µL, 0.26 mmol) was

used with all other general synthesis conditions for the amino derivatives.

The product was purified by silica gel flash column chromatography with

92:8 DCM/MeOH to yield an average of 67.3 mg (63%). IR: 3288, 2936,

-1 + 1627, 1228 cm . HRMS: Calculated for C27H29N3NaO2: 450.2152 (M+Na ), found

+ 1 450.2152 (M+Na ). H-NMR (CDCl3): δ 8.64 ppm (1H, m), 7.93 (1H, d, J = 9.2 Hz),

7.74 (2H, m), 7.68 (1H, d, J = 2.7), 7.45 (1H, m), 7.34 (4H, m), 6.83 (1H, br), 6.17 (1H, t,

J = 10.0), 5.94 (1H, m), 5.10 (2H, m), 3.96 (3H, s), 3.54 (1H, m), 3.13 (1H, m), 2.84 (2H,

45

m), 2.56 (1H, m), 2.31 (1H, br), 2.02 (1H, m), 1.79 (1H, br), 1.69 (1H, m), 1.52 (2H, m).

13 C-NMR (CDCl3): δ 167.27 ppm, 158.14, 147.36, 144.5, 143.65, 143.95, 141.65,

133.83, 131.79, 131.37, 128.59, 128.43, 127.99, 126.94, 122.17, 119.40, 114.59, 101.48,

57.69, 55.74, 49.67, 41.37, 39.29, 27.35, 27.32, 25.20.

9-((4-trifluoromethyl)-benzoyl)amino-(9-deoxy)quinine (33).

4-(Trifluoromethyl)benzoyl chloride (38.6 µL, 0.26 mmol) was used

with all other general synthesis conditions for the amino derivatives.

The product was purified by silica gel flash column chromatography with 92:8 DCM/MeOH to yield an average of 76.8 mg (62%). IR: 3268, 2941, 1621,

-1 + 1326 cm . HRMS: Calculated for C28H29F3N3O2: 496.2206 (M+H ), found 496.2206

+ 1 (M+H ). H-NMR (CDCl3): δ 8.86 ppm (1H, d, J = 4.5 Hz), 7.76 (2H, m), 7.67 (2H, m),

7.54 (2H, m), 7.34 (1H, t, J = 7.7), 7.05 (1H, m), 6.74 (1H, s), 6.63 (1H, d, J = 16.0), 6.51

(1H, dd, J = 7.6, 15.8), 4.58 (1H, m), 3.49 (2H, m), 3.39 (1H, m), 3.19 (1H, m), 2.82 (1H, m), 2.53 (1H, m), 2.09 (1H, s), 1.98 (2H, m), 1.72 (1H ,m), 1.08 (1H, m). 13C-NMR

(CDCl3): δ 166.00 ppm, 158.11, 147.23, 144.57, 143.74, 141.68, 137.01, 133.46, 133.13,

131.27, 128.30, 127.36, 125.50, 125.47, 124.70, 122.05, 121.99, 119.29, 114.44, 101.34,

57.43, 55.78, 55.62, 49.96, 41.35, 39.29, 27.40, 27.34, 25.31.

9-(benzylcarbamoyl)-(9-deoxy)quinine (34). Benzyl chloroformate (39.1 µL, 0.26

mmol) was used with all other general synthesis conditions for the

amino derivatives. The product was purified by silica gel flash column

chromatography with 92:8 DCM/MeOH to yield an average of 56.1 mg

-1 (49%). IR: 3317, 2941, 1709, 1229 cm . HRMS: Calculated for C28H32N3O3:

+ + 1 458.2438 (M+H ), found 458.2438 (M+H ). H-NMR (CDCl3): δ 8.69 ppm (1H, m),

46

7.97 (1H, d, J = 9.2 Hz), 7.56 (1H, d, J = 2.5), 7.32 (5H, m), 7.23 (2H, m), 5.95 (1H, m),

5.59 (1H, t, J = 10.3), 5.21 (1H, br), 5.09 (4H, m), 3.85 (3H, s), 3.36 (1H, m), 3.09 (1H, m), 2.85 (1H, m), 2.73 (1H, m), 2.52 (1H, m), 2.30 (1H, br), 2.07 (1H, m), 1.87 (1H, br),

13 1.71 (1H, m), 1.53 (2H, m). C-NMR (CDCl3): δ 158.05 ppm, 156.44, 147.48, 144.84,

144.42, 141.86, 136.13, 131.58, 128.45, 128.20, 128.11, 127.67, 121.97, 118.73, 114.41,

101.18, 67.05, 57.85, 55.83, 55.56, 51.83, 41.35, 39.50, 27.54, 27.48, 25.54.

9-(t-butylcarbamoyl)-(9-deoxy)quinine (35). Di-tert-butyl dicarbonate (56.7 mg, 0.26

mmol) was used with all other general synthesis conditions for the amino

derivatives. The product was purified by silica gel flash column

chromatography with 92:8 DCM/MeOH to yield an average of 81.5 mg

-1 (77%). IR: 3217, 2939, 1699, 1229 cm . HRMS: Calculated for C25H34N3O3:

+ + 1 424.2595 (M+H ), found 424.2595 (M+H ). H-NMR (CDCl3): δ 8.73 ppm (1H, d, J =

4.6 Hz), 7.98 (1H, d, J = 9.2), 7.61 (1H, d, J = 2.4), 7.34 (1H, dd, J = 2.6, 9.2), 7.30 (1H, d, J = 4.6), 5.98 (1H, m), 5.55 (1H, t, J = 10.4), 5.11 (2H, m), 4.70 (1H, m), 3.97 (3H, s),

3.36 (1H, m), 3.12 (1H, m), 2.82 (2H, m), 2.55 (1H, m), 2.31 (1H, m), 2.09 (1H, m), 1.89

13 (1H, m), 1.75 (1H ,m), 1.56 (2H, m), 1.41 (9H, s). C-NMR (CDCl3): δ 158.02 ppm,

155.72, 147.48, 144.85, 144.61, 141.96, 131.51, 128.32, 121.99, 118.63, 114.32, 101.18,

79.76, 57.71, 55.73, 55.55, 50.91, 41.26, 39.55, 28.21, 27.54, 27.50, 25.16.

9-(p-toluenesulfonyl)amino-(9-deoxy)quinine (36). p-Toluenesulfonyl chloride (49.6

mg, 0.26 mmol) was used with all other general synthesis conditions for

the amino derivatives. The product was purified by silica gel flash

column chromatography with 95:5 DCM/MeOH to yield an average of

72.8 mg (61%). IR: 3269, 2941, 1622, 1160 cm-1. HRMS: Calculated for

47

+ + 1 C27H32N3O3S: 478.2159 (M+H ), found 478.2159 (M+H ). H-NMR (CDCl3): δ 8.46 ppm (1H, d, J = 4.5 Hz), 7.80 (1H, d, J = 9.2), 7.25 (1H, m), 7.14 (4H, m), 6.61 (2H, d, J

= 7.9), 5.90 (1H, m), 5.03 (3H, m), 3.93 (3H, s), 3.29 (1H, br), 2.94 (2H, m), 2.47 (2H, m), 2.23 (2H, m), 2.09 (3H, s), 1.87 (1H, br), 1.65 (2H, m), 1.48 (1H, m). 13C-NMR

(CDCl3): δ 157.44 ppm, 147.12, 144.21, 142.86, 141.68, 136.54, 131.31, 128.41, 127.34,

126.28, 121.29, 114.44, 100.98, 56.26, 55.54, 41.73, 39.65, 27.61, 26.81, 21.07.

9-(benzoylthiourea)-(9-deoxy)quinine (37). Benzoyl isothiocyanate (36.0 μL, 0.26

mmol) was used with all other general synthesis conditions for the

amino derivatives. The product was purified by silica gel flash column

chromatography with a gradient solvent system of 1-2.5% MeOH in

DCM to yield an average of 90.0 mg (74%). IR: 3226, 2934, 1521, 1245 cm-1. HRMS:

+ + 1 Calculated for C28H31N4O2S: 487.2162 (M+H ), found 487.2162 (M+H ). H-NMR

(CDCl3): δ 11.27 ppm (1H, d, J = 9.3 Hz), 9.15 (1H, br), 8.77 (1H, d, J = 4.6), 7.99 (1H, d, J = 9.2), 7.86 (1H, d, J = 2.6), 7.76 (2H, m), 7.57 (1H, m), 7.44 (3H, m), 7.35 (1H, dd,

J = 2.6, 9.2), 6.60 (1H, t, J = 9.8), 5.94 (1H, m), 5.06 (2H, m), 4.02 (3H, s), 3.60 (1H, m),

3.08 (2H, m), 2.70 (1H, m), 2.59 (1H, m), 2.29 (1H, m), 2.07 (1H, m), 1.87 (3H, m), 1.55

13 (1H, m). C-NMR (CDCl3): δ 180.39 ppm, 166.96, 158.02, 147.57, 144.91, 133.62,

131.60, 131.27, 128.99, 128.13, 127.34, 122.17, 119.06, 114.48, 102.02, 59.28, 56.43,

56.07, 56.04, 41.79, 39.40, 27.47, 27.42, 24.85.

48

Synthetic Method of Phthalimide Derivatives

9-(phthalimide)-(9-deoxy)-epi-quinine (38). 9-Amino-(9-deoxy)-epi-quinine (21, 0.25

mmol) and phthalic anhydride (34.1 mg, 0.23 mmol) were dissolved in dry

toluene (1 mL). The mixture was stirred overnight at reflux and then

concentrated in vacuo. The product was purified by silica gel flash column chromatography with 92:8 DCM/MeOH to yield an average of 73.0 mg (70%).

-1 IR: 2950, 1705, 1383, 1230 cm . HRMS: Calculated for C28H28N3O3: 454.2125

+ + 1 (M+H ), found 454.2125 (M+H ). H-NMR (CDCl3): δ 8.82 ppm (1H, d, J = 4.6 Hz),

8.01 (1H, d, J = 9.2), 7.82 (3H, m), 7.69 (1H, m), 7.63 (2H, m), 7.34 (1H, dd, J = 2.7,

9.2), 5.99 (2H, m), 5.10 (2H, m), 4.39 (1H, m), 4.03 (3H, s), 3.28 (1H, m), 3.13 (1H, m),

2.81 (1H, m), 2.66 (1H, m), 2.29 (1H, m), 1.95 (1H, m), 1.73 (1H, m), 1.56 (2H ,m). 13C-

NMR (CDCl3): δ 168.45 ppm, 167.94, 158.32, 147.28, 144.85, 141.87, 139.04, 133.97,

133.77, 132.08, 131.80, 131.42, 128.87, 123.31, 123.12, 122.20, 122.00, 114.42, 101.10,

56.09, 55.78, 53.48, 50.77, 41.30, 39.66, 28.17, 27.84, 27.63.

9-(phthalimide)-(9-deoxy)quinine (39). 9-Amino-(9-deoxy)quinine (22, 0.25 mmol)

was used with the same reaction and purification conditions from above to

yield an average of 102.2 mg (98%). IR: 2942, 1705, 1380, 1228 cm-1.

+ HRMS: Calculated for C28H28N3O3: 454.2125 (M+H ), found 454.2125

+ 1 (M+H ). H-NMR (CDCl3): δ 8.84 ppm (1H, d, J = 4.7 Hz), 7.97 (1H, d, J = 9.2), 7.91

(1H, d, J = 4.7), 7.85 (1H, m), 7.69 (4H, m), 7.31 (1H, dd, J = 2.6, 9.2), 6.08 (1H, d, J =

11.5), 5.99 (1H, m), 5.09 (2H, m), 4.47 (1H, m), 4.01 (3H, s), 3.18 (1H, m), 3.00 (1H, m),

2.89 (1H, m), 2.64 (1H, m), 2.33 (1H, m), 1.95 (1H, m), 1.84 (1H ,m), 1.74 (1H, m), 1.20

13 (1H, m). C-NMR (CDCl3): δ 168.72 ppm, 167.89, 158.10, 147.49, 144.96, 141.72,

49

140.04, 134.32, 134.15, 131.89, 128.32, 123.39, 122.19, 121.61, 114.67, 100.70, 55.99,

55.71, 53.65, 50.36, 40.86, 39.78, 27.74, 27.58, 25.67.

Synthetic Method of Benzyl Protected Amino Derivatives

9-(benzyl)amino-(9-deoxy)-epi-quinine (40). 9-Amino-(9-deoxy)-epi-quinine (21, 0.25

mmol) was dissolved in methanol (1 mL) and cooled to 0°C.

Benzaldehyde (38.9 μL, 0.375 mmol) was added and the mixture was

allowed to warm to room temperature over 24h. Then, sodium borohydride (14.2 mg, 0.375 mmol) was added at 0°C and the reaction continued to stir at room temperature for another 24h. The product was concentrated under reduced pressure and purified by silica gel flash column chromatography with 92:8 DCM/MeOH to yield an average of 54.2 mg (57%). IR: 3303, 2933, 1620, 1237 cm-1. HRMS:

+ + 1 Calculated for C27H31N3NaO: 436.2359 (M+Na ), found 436.2359 (M+Na ). H-NMR

(CDCl3): δ 8.81 ppm (1H, m), 8.05 (1H, m), 7.83 (1H, d, J = 4.4 Hz), 7.38 (1H, m), 7.24

(5H, m), 7.13 (1H, m), 5.69 (1H, m), 4.92 (2H, m), 4.38 (1H, d, J = 10.0), 3.94 (1H, s),

3.82 (3H, s), 3.68 (1H, m), 3.36 (1H, m), 3.19 (1H, dd, J = 10.4, 13.6), 2.87 (2H, m), 2.67

13 (2H, m), 2.22 (1H, m), 1.52 (3H ,m), 1.19 (1H, m), 0.79 (1H, m). C-NMR (CDCl3): δ

157.38 ppm, 148.19, 146.60, 144.38, 141.51, 140.47, 131.76, 129.78, 128.42, 128.15,

126.83, 121.30, 120.25, 114.25, 100.83, 68.22, 62.48, 55.95, 55.27, 55.13, 50.63, 40.83,

39.70, 28.10, 27.43, 25.01.

9-(benzyl)amino-(9-deoxy)quinine (41). 9-Amino-(9-deoxy)quinine (22, 0.25 mmol)

was used with the same reaction and purification conditions from above

to yield an average of 35.2 mg (37%). IR: 3292, 2932, 1621, 1241 cm-

50

1 + + . HRMS: Calculated for C27H31N3NaO: 436.2359 (M+Na ), found 436.2359 (M+Na ).

1 H-NMR (CDCl3): δ 8.79 ppm (1H, br), 8.04 (1H, d, J = 9.2 Hz), 7.46 (1H, m), 7.37 (2H, dd, J = 2.7, 9.2), 7.29 (3H, m), 7.20 (2H, m), 5.89 (1H, m), 5.04 (2H, m), 3.87 (3H, s),

3.57 (2H, d, J = 13.2), 3.43 (1H, m), 2.98 (1H, m), 2.53 (2H, m), 2.25 (1H, m), 2.14 (1H,

13 m), 1.87 (1H, m), 1.62 (1H, m), 1.50 (1H ,m). C-NMR (CDCl3): δ 157.51 ppm, 147.69,

147.43, 144.72, 141.68, 140.02, 135.88, 131.84, 131.33, 130.76, 129.51, 128.97, 128.76,

128.44, 128.33, 128.22, 127.72, 127.47, 127.08, 126.91, 121.52, 120.24, 114.57, 101.63,

60.84, 60.35, 60.28, 56.21, 55.62, 51.38, 42.57, 42.17, 39.58, 29.66, 27.78.

51

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58

APPENDIX

QN-3.

59

QN-4.

60

CD-1.

61

CD-2.

62

CD-3.

63

CD-4.

64

QD-1.

65

QD-2.

66

QD-3.

67

QD-4.

68

CN-1.

69

CN-2.

70

CN-3.

71

CN-4.

72

epi-quinine (20).

73

9-amino-(9-deoxy)-epi-quinine (21).

74

9-amino-(9-deoxy)quinine (22).

75

9-(priopionyl)amino-(9-deoxy)-epi-quinine (24).

76

9-(benzoyl)amino-(9-deoxy)-epi-quinine (25).

77

9-((4-trifluoromethyl)-benzoyl)amino-(9-deoxy)-epi-quinine (26).

78

9-(benzylcarbamoyl)-(9-deoxy)-epi-quinine (27).

79

9-(t-butylcarbamoyl)-(9-deoxy)-epi-quinine (28).

80

9-(p-toluenesulfonyl)amino-(9-deoxy)-epi-quinine (29).

81

9-(benzoylthiourea)-(9-deoxy)-epi-quinine (30).

82

9-(priopionyl)amino-(9-deoxy)quinine (31).

83

9-(benzoyl)amino-(9-deoxy)quinine (32).

84

9-((4-trifluoromethyl)-benzoyl)amino-(9-deoxy)quinine (33).

85

9-(benzylcarbamoyl)-(9-deoxy)quinine (34).

86

9-(t-butylcarbamoyl)-(9-deoxy)quinine (35).

87

9-(p-toluenesulfonyl)amino-(9-deoxy)quinine (36).

88

9-(benzoylthiourea)-(9-deoxy)quinine (37).

89

9-(phthalimide)-(9-deoxy)-epi-quinine (38).

90

9-(phthalimide)-(9-deoxy)quinine (39).

91

9-(benzyl)amino-(9-deoxy)-epi-quinine (40).

92

9-(benzyl)amino-(9-deoxy)quinine (41).

93

QN-3.

94

QN-4.

95

CD-1.

96

CD-2.

97

CD-3.

98

CD-4.

99

QD-1.

100

QD-2.

101

QD-3.

102

QD-4.

103

CN-1.

104

CN-2.

105

CN-3.

106

CN-4.

107

epi-quinine (20).

108

9-amino-(9-deoxy)-epi-quinine (21).

109

9-amino-(9-deoxy)quinine (22).

110

9-(priopionyl)amino-(9-deoxy)-epi-quinine (24).

111

9-(benzoyl)amino-(9-deoxy)-epi-quinine (25).

112

9-((4-trifluoromethyl)-benzoyl)amino-(9-deoxy)-epi-quinine (26).

113

9-(benzylcarbamoyl)-(9-deoxy)-epi-quinine (27).

114

9-(t-butylcarbamoyl)-(9-deoxy)-epi-quinine (28).

115

9-(p-toluenesulfonyl)amino-(9-deoxy)-epi-quinine (29).

116

9-(benzoylthiourea)-(9-deoxy)-epi-quinine (30).

117

9-(priopionyl)amino-(9-deoxy)quinine (31).

118

9-(benzoyl)amino-(9-deoxy)quinine (32).

119

9-((4-trifluoromethyl)-benzoyl)amino-(9-deoxy)quinine (33).

120

9-(benzylcarbamoyl)-(9-deoxy)quinine (34).

121

9-(t-butylcarbamoyl)-(9-deoxy)quinine (35).

122

9-(p-toluenesulfonyl)amino-(9-deoxy)quinine (36).

123

9-(benzoylthiourea)-(9-deoxy)quinine (37).

124

9-(phthalimide)-(9-deoxy)-epi-quinine (38).

125

9-(phthalimide)-(9-deoxy)quinine (39).

126

9-(benzyl)amino-(9-deoxy)-epi-quinine (40).

127

9-(benzyl)amino-(9-deoxy)quinine (41).

128