Ian R. Baxendale Synthesis of Grossamide Second Input Stream Loading Step H2O2–Urea Complex Acetone / H2O (10:1)

Ian R. Baxendale Synthesis of Grossamide Second input stream loading step H2O2–urea complex Acetone / H2O (10:1)

DMFTHF

Enzyme

Grossamide

Heater/Cooler module a reactor chip -40-150 oC Two HPLC pumps 100-10,000 µL/min 35 bar system pressure 2 reagent loading channels from liquid handling unit UV/diode array detection Split stream real-time MS analysis for optimisation In-line reverse phase preparative purification – Mass directed Fully software controlled via UNIPOINT + DoE software

Synlett 2006, 427. Synthesis of Oxazoles and Thiazoles in Flow

35 Oxazoles structures prepared, some on 10-25g scale. Org. Lett. 2006, 8, 5231.

R= NO2 90% 2-OMe 89% 4-OMe 96% 3-F 68% 90% 4-Cl 48% 12:5 89% 4 -Br 53% 4:5 94% 89%

25-55 oC MeCN

50-96%

85% 88% 85% 5:4 87% J. Comb. Chem. 2008, 10, 851. 2:1 86% Synlett, 2010, 5, 749 3+2 Cycloaddition Reactions Heterocycles, 2011, 82, 1297

MeCN

SiO or 2 6030 min, min, 60 80-100 oC oC Fluorination using DAST

DAST

SynLett. 2008, 2111. Azide coupling in Flow

QP-TU Purities greater than 95%

95% 91% 89%

90%

82% 98% 91% 89%

96% 94%

93%

81% 85% 87% 88% 88%

93% 70% 85%

Org. Biomol. Chem. 2007, 5, 1559. Azides: Preparation in Flow

TMS-N3

MeCN Back pressure 10 min regulator 60 oC

Org. Biomol. Chem. 2011, 9, 1927 Preparation of Alkynes in Flow : Seyferth-Gilbert

QP-BZA QP-SA QP-DMA

30 min o 70 C Evaporate 100 oC

Angew. Chem. Int. Ed., 2009, 48, 4017. Seyferth-Gilbert: Extended Sequence

Oxidation (1.5 equiv.)

Couple and Sequester Cu

(2 equiv.)

MeCN (1 equiv.) 60 oC QP-TU

t-BuOK in MeOH 30 min (2 equiv.) 100 oC

QP-SA QP-DMA QP-BZA

70 oC

Scavenge Angew. Chem. Int. Ed., 2009, 48, 4017. Triazole Synthesis in Flow

TMS-N3

MeCN

60 oC

Cartridge recycled MeCN Cartridge consumed

Org. Biomol. Chem. 2011, 9, 1938 Polymeric Monoliths

ProductWaste

Mono DVB Porogen Solvent AIBN Temp. Heat 80-100 oC 35% 20% 40% 5% v/v 1 mol% 80 oC

Substrates Curtius-Rearrangements in Flow Using Azide Monoliths

150 mm

15 mm

15-18 mmol N3 Org. Biomol. Chem. 2008, 6, 1587. Stauginger Aza Wittig Reaction Azides

MeOH Aldehydes

NH3/MeOH

65-99% isolated yield, >95% purity

Org. Biomol. Chem. 2011, 9, 1927 Casein Kinase I-ε/δ Inhibitors

• Targeting Kinases: A typical medicinal chemistry project

• Potential regulators of circadian rhythm: sleep disorders/mood disorders

• Target oriented application of flow technologies: challenging steps, solubility issues Imidazo [1,2-b]pyridazine/Sanofi-Aventis

Reactivity/Chemoselectivity Organometallic reagents Mono vs multi addition (moisture, oxygen, precipitation, stability)

High temperature Chemoselectivity Purification of final product Solubility of product

Org. Biomol. Chem., 2010, 8, 1798. Casein Kinase I-ε/δ Inhibitors

Imidazo [1,2-b]pyridazine/Sanofi-Aventis

Employing organometallic reagents in flow: • 50.0 mmol reaction scale - 100 mmol of BuLi (× 2 eq.) was handled safely

Note: no more than 4.0 mmol at a time

• Continuous throughput of 6.0 mmol/hour (1.3 g/h) Org. Biomol. Chem., 2010, 8, 1798. Casein Kinase I-ε/δ Inhibitors Org. Biomol. Chem., 2010, 8, 1798.

MeOH K2CO3 0.3 ml/min quantitative 0.1 M in EtOH

40%

Pure product precipitated upon addition of water. 0.2 M in EtOH

0.1 ml/min 0.05 M in EtOH

BPR 52% CH2Cl2

Vapourtec V-10 0.1 ml/min 2.0 M in EtOH Casein Kinase I-ε/δ Inhibitors 0.15 mL/min DBU Synthesis of Gleevec N2 in 2:1 Dioxane/tBuOH

Exhaust

DCM K2CO3 RT SiO2

0.4 mL/min 80 oC 25 min 30 min DCM 0.15 mL/min

50 °C

Convergent synthesis Catalyst system Prepared from Ynone 150 oC 30 min

H2O 0.1 mL/min

32% isolated yield After chromatography

Chem. Commun., 2010, 46, 2450. Ynone Synthesis – numbering out

Pd(OAc)2 (1 mol%) OR H2N-NHR’’ (iPr)2NEt (1.2 equiv.) DCM QP-TU

NaOH (1.1 equiv.) 40 min, 100 oC 1:1 EtOH/H2O

30 min, 100-130 oC

Aqueous Water output

MgSO4

NH3 in MeOH/DCM

Catch and Release

Chem. Eur. J., 2010, 16, 89-94 Stream Splitting in Flow

Input 1 Input 2 60% yield 20 min 100 oC Product 1 87% yield

Pd(OAc)2 (1 mol%) 30 min o (iPr)2NEt (1.2 equiv.) Product 2 100 C CaCO3

DCM QP-TU 88% yield Product 3 20 min 30 min, 100 oC 120 oC Product 4

Input 3 71% yield 20 min Input 4 Chem. Eur. J., 2010, 16, 89-94 100 oC d-Opioid Receptor Agonist

0.125 ml/min 20 min, RT

THF

40 min, RT

0.125 ml/min 0.25 ml/min

SiO2

React IR Flow cell 0.5 ml/min

10 min, 60 oC

60 oC

RT To waste

35% overall yield NH3/MeOH Catch and release

Chem. Eur. J. , 2010, 16, 12342. Potent 5HT1B Antagonist

0.5 ml/min

0.5 M 10% Pd/C EtOH H-Cube 70 oC Full H2 mode

0.5 M 10 min, 135 oC 0.5 ml/min

99%

18%, 95% purity 0.4 ml/min 0.24 M 0.24 M in DMF 0.20 M in PhMe 0.4 ml/min Catch and release purification 0.1 ml/min

NH3/MeOH release.

250 oC 250 psi 10 min, 130 oC 14 min

K CO rt, 50 min 2 3

1:1 mixture; 0.5 M 0.1 ml/min, DMF SynLett 2010, 505-508 Synthesis of an IRE-1 binding probe

Duff Reaction

15-22%

• Cheap starting materials/reagents

• Scaleable via the same route

• Highly reproducible

• Automated synthesis

• Avoid work-up/purification

Selective inhibition of unconventional mRNA splicing by an IRE1-binding small molecule

PNAS, 2012, doi:10.1073/pnas.1115623109 Route A: N-oxide Derived Synthesis

DCM/EtOH 83 ml/min 83 ml/min

DCM/EtOH 2:1 93% 1 h, 125 oC 91% 1 h, 120 oC 83 ml/min 83 ml/min 83 ml/min DCM

1 h, 0 oC

166 ml/min

rt 82%

1 h 66% Isolated by filtration 1 M HCl 83 ml/min overall yield 46% DCM

Chem. Euro. J. 2012, 32, 9901-9910 Route B: Claisen Rearrangement Route B: Claisen Rearrangement

NMP solvent

A B

Loading stream Wash stream Detection at 330 nm

10 cartridges loaded sequentially in a fully automated procedure

Breakthrough ~ 2 M of substrate Route B: Claisen Rearrangement 2 1

Chem. Euro. J. 2012, 32, 9901-9910 Route B: Claisen Rearrangement 0.02 mm id tubing T-piece connector 4 mm id Gas flow Liquid substrate feed tubing

Taken using UV light profiling Gas feed

Fluid flow Gas flow

51% overall yield Merclinertant and SR 142948A

Neurotensin physiologically roles in a variety of biological processes, • temperature control • pain sensation, • modulation of appetite • pituitary hormone secretion • disruption of NT’s binding proposed as a possible treatment of schizophrenia and Parkinson’s disease • up-regulation of NT receptor (NTR) expression is linked with cancer

3 Neurotensin receptors. NTR 1 and NTR 2 are both seven-transmembrane G-coupled protein receptors NTR3 (showing 100% identity with Sortilin) possess a single transmembrane domain

Neurotensin has poor stability in vivo and is degraded by several endopeptidases and metalloproteases.

Its size prevents passage across the blood brain barrier resulting in poor bioavailability (injection CNS).

Offers NTR agonism, however, study of these receptors require access to antagonists of NTR receptor function.

Sanofi-Aventis Levocabastine - Novartis Meclinertant SR 48692 SR 142948A

Selectively binds to NTR2

NTR1 antagonist (Ki = 2.6 ±0.2 nM) Binds NTR1 and NTR2 NTR2 (Ki = 418±82.2 nM) and NTR3 (IC50 = 238±46 nM) but much more selective for NTR2. Continuous Microwave Synthesis

Meclinertant SR 48692

Bucherer-Berg strategy

0.5 L; 0.5 M 1.2 L; 0.25 M 81-84% 2 steps Processing times for Bucherer-Lieb synthesis. STEP 1 Heating Reaction Cooling Wash Total Cycles Total times time times and prep cycle required processing times time time Voyager 14.5 min 90 min 20 min 11.5 min 130 min 24 54 hours Vials 4 min 90 min 6 min 1 min 102 min 60 101 hours STEP 2 Voyager 20 min* 180 min 24 min 12 min 236 min 10 39.3 hours Vials 9 min* 180 min 7 min 2 min 198 min 25 82.5 hours

*Needed to be heated at reduced power to prevent overpressure.

Amino acid preparation issue

Meclinertant SR 48692 SR 142948A

Poor subsequent conversion in derivatization reactions - needed 3-4 equivalents to prepare adducts in expected yields.

Microanalysis (Observed C = 36-48%, Desired 67.7%).

Full conversion of the hydantoin and extent of inorganic 1 impurities could be determined by H NMR (D2SO4) analysis of samples of material doped with known concentration of p-Anisidine

(result: approx 30% of material by mass). Preparations following other known literature methods gave identical or worse purities of the hydantoin.

Required development of a new synthetic route ! Adamantane Amino acid Synthesis

Grignard addition Ritter reaction 0.65 M 0.1 M AcOH/MeCN 1:1 14 mL 14 mL 0.2 mL/min 1 mL/min 40 oC Ultra sonication RT

0.5 M in THF 37 min 7 min 0.18 mL/min 88% isolated

AcOH/Ac O/H SO KOH 3 M in H2O 91% isolated NH4Cl 2 2 4 2:1:1 3 mL/min 0.5 M in THF 3 M in H2O 0.2 mL/min 0.18 mL/min 1 mL/min

5-endo-exo-dig cyclisation Hydrolysis ozonolysis

125 oC 94% 47 min Overall yield 68% 99% isolated 91% isolated O3 1 bar KOH 0.8 M HCl/H2O/AcOH 9:2:1 500 mL/min 0.5 M in DCM H2O/EtOH 4:1 8 mL/min 0.1 mL/min

92% 92% 97%

Overall yield 72%

Org. Process Res. Dev. 2012, 16, 798-810. Adamantane Amino acid Synthesis Scale-up Synthesis in Flow

60 L 56.63 moles 1.2 equiv. Conc: 0.94 M

30 L 47.19 moles NaS2O3/NaOH 1.5 M Conc: 1.57 M

Exotherm waste Regulated <55 oC 30 L 51.91 moles Ambient 1.1 equiv. Conc: 1.73 M temperature Aqueous 75 oC Organic Ambient temperature

SR 142948A (Sanofi-Aventis) Generate~12 kg SR 142948A Scale-out Synthesis in Flow

NaS2O3/NaOH 1M

1.5 mL/min waste 3 mL/min per channel Aqueous Organic

30 L 51.91 moles 30 L 47.19 moles 1.1 equiv. Conc: 1.73 M Conc: 1.57 M Max 2.5 mL/min

Exotherm Regulated <55 oC 12 mL/min flow rate Increase residence time

60 L 56.63 moles 12 ways split 1.2 equiv. Conc: 0.94 M 75 oC 2 mL/min per channel 3 channels 6.9 days processing 120 L of reaction solution 11.5 kg 95% Scale-up Synthesis in Flow SR 142948A

Gas bubble Liquid Liquid Pd nanoparticles

Gas vent Et3N (3 equiv.)

EtOH QP-SA QP

EtOH HPLC pump - Pd(dppf)Cl2 35 min TU (3.5-5 mol%) 20 bar (+ Additive) 90 oC 5 cm Pressure regulator

7 bar CO 5 cm Sediment tank

1.8 kg; 92% purity Scale-up Synthesis in Flow SR 142948A

Mixing Chip 2 mL

QP-SA QP

1 h 15 min - 105 oC TU TMG, EtOH, CuI (0.02 mol%)

Pd(PPh3)2Cl2 (0.01 mol%) PPh , MeOH 3 >95% conversion

80 oC 3.5 h RuO2 0.25 mol% KIO4 2.2 equiv. Na2CO3/H2O 3 M 40 oC, 3.5 h >99% conversion 0.1 mL/min >94% conversion 72% isolated yield

NaOH (2.5 M) Hydrazine Formation in Flow

tBuONO 0.3 M in MeCN 0.4 mL/min

H2O 0.3 M in MeCN 0.4 mL/min

2 mL volume . BF3 Et2O 100 min run 0.45 M in MeCN 4.25 g 0.4 mL/min 98% yield

L-ascorbic acid 0.4 M in MeCN 0.4 mL/min Tetrahedron 2011, 67, 10296-10303.

RT, 5 min 60 oC, 20 min

0.2 M in MeCN o 0.5 mL/min µW 120 C 2 h 2 mL volume tBuONO 0.2 M in MeCN 0.5 mL/min

L-ascorbic acid 0.4 M in H O 2 72% 0.5 mL/min Scale-up Synthesis in Flow

Meclinertant SR 48692 SR 142948A

1.1 M NaOEt 2-Me-THF EtOH 2 M aq. HCl 0.25 M 0.5 mL/min 1.0 mL/min 60 oC, 16 min

> 95% conversion Precipitation !!!

0.375 M 1.0 mL/min 2-Me-THF KMnO4 Nef Oxidation in Flow

5-8 min

H2O

Exothermic

MeOH + KOH (1 equiv.) (1.2 equiv.)

Org. Lett. 2010, 12, 3618. Heterogeneous flow mixtures

Coflore ACR (Agitated Cell reactor) flow reactor Heterogeneous flow mixtures 4 mL/min 0.3 M in hexane

8 mL/min 0.15 M in DCM

12 mL/min, 0.1 M 94% isolated yield

Org. Process Res. Dev., 2011, 15, 693–697 Scale-up Synthesis in Flow

Meclinertant SR 48692 (Sanofi-Aventis) SR 142948A (Sanofi-Aventis)

1.1 M NaOEt 2-Me-THF EtOH 2 M aq. HCl 0.25 M 0.5 mL/min 1.0 mL/min 60 oC, 16 min Isolated by filtration

> 95% 78% isolated conversion Precipitation !!!

0.375 M 1.0 mL/min 2-Me-THF ~ £6.50 per gram

2',6'-Dimethoxyacetophenone Scale-up Synthesis in Flow

15 oC 35 oC, 10 min 0.5 M Mixing Chip 2mL 2-MeTHF 0.5 mL/min

Iodine 0.6 M 1.0 mL/min

2-MeTHF 0.55 M 0.5 mL/min

185 oC, 1 h 90 oC, 2 h 90 oC, 1 h

KOH/H2O KOH/H2O Scale-up Synthesis in Flow

15 oC 35 oC, 10 min 0.5 M Mixing Chip 2mL 2-MeTHF 0.5 mL/min

Iodine 0.6 M 1.0 mL/min

2-MeTHF 0.55 M 0.5 mL/min MeOH 0.5 M Et3N, MeOH, CuI (0.02 mol%) 0.3 mL/min 35 oC, 7 min

QP-TU

100 oC, 35 min

NIS 2.2 equiv.

(MeO)3CH 3 equiv. 0.3 mL/min Pd(PPh3)2Cl2 (0.01 mol%) PPh3, MeOH MeOH/2-MeTHF

120 oC, 1.15 h 120 oC, 2 h

5 M HCl 2.5 M NaOH Department of Chemistry E-mail: [email protected]

Past Members of the ITC

Dr Francesco Tozzi Dr Steve Lanners Dr Jason Tierney Current Members Dr Lucia Tamborini Dr Tash Polyzos Dr Peter Koos Dr Heiko Lange Celeste Iannuzzi Maria Dr Victoria Rojo Dr Lucie Guetzoyan Dr Laetitia Martin Dr Malte Brasholz Dr Catherine Carter Dr Nikzad Nikbin Dr Matt Kitching Dr Francesco Venturoni Dr Elena Riva Kim Roper Dr Jorg Sedelmeir Dr John Hayward Olivia Dixon Sean Newton Dr Chris Smith Trine Petersen Dr Sam Qian Ben Deadman Dr Christian Hornung Antti Kataja Dr Tobias Brodmann Sam Bourne Dr Jane Jin Dr Jens Wegner Claudio Battilocchio Ben Bhawal Dr Catherine Smith Dr Mark Hopkin Richard Ingham Dr Rainer Martin Dr Keiji Nakayama Dr Marcus Baumann Dr Ulrike Gross

Special thanks to the following organisations for their generosity and friendship Advion, AM Technologies, EPSRC, Syngenta, The Royal Society, Unilever, Uniqsis.