ATTEMPTS to SYNTHESIZE VINYL THIAZOLES by Geraldine Ann Ciko
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Attempts to synthesize vinyl thiazoles Item Type text; Thesis-Reproduction (electronic) Authors Ciko, Geraldine Ann, 1941- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 28/09/2021 14:14:24 Link to Item http://hdl.handle.net/10150/318492 ATTEMPTS TO SYNTHESIZE VINYL THIAZOLES by Geraldine Ann Ciko A Thesis Submitted to the Faculty of the DEPARTMENT OF CHEMISTRY In Partial Fulfillment of the Requirements For the Degree of MASTER OF SCIENCE In the Graduate College THE UNIVERSITY OF ARIZONA 19 66 STATEMENT BY AUTHOR This thesis has been submitted in partial fulfillment of requirements for an advanced degree at The University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED APPROVAL BY THESIS DIRECTOR This thesis has been approved on the date shown below: JAMES E. MULVANEY Associate Professor of Chemistrys ti ACKNOWLEDGMENT I would like to thank Dr. James Mulvaney for directing this work and for the interest and patience he has shown throughout my two years of graduate study. I would also like to thank my parents, without whose love, devotion, and encouragement my attainment of this degree would not have been possible. TABLE OF CONTENTS Page LIST OF TABLES . vi ABSTRACT ***•**♦*♦♦*♦♦•*♦*♦*«♦«»♦•»♦»♦♦♦•♦*•#»* yii INTRODUCTION 1 DISCUSSION OF RESULTS , . , , ................................... 7 EXPERIMENTAL 19 Friedel-Crafts Reaction of Chloroacetyl Chloride and Ethylene 19 Methyl Vinyl Ketone and Thioacetamide with Sulfuryl Chloride ............... 20 Methyl Vinyl Ketone and Thioacetamide with Iodine . .... 21 Methyl Vinyl Ketone and Thioacetamide with Thionyl C h lo rid e ...................................................... 21 Acrylonitrile and Hydrogen Sulfide ........................ 21 Acrylamide and Phosphorus Pentasulfide in Xylene ..... 22 Acrylamide and Phosphorus Pentasulfide in Chloroform . 23 Methacrylamide and Phosphorus Pentasulfide in Chloroform ....................................... 24 Thioacrylamide and Chloroacetaldehyde . .................. 24 Thioacrylamide and Chloroacetal in Ethanol .......... 25 Acrylamide, Phosphorus Pentasulfide, and Chloroacetone ................................................ ...... 25 Thioacrylamide and Chloroacetal in Hydrochloric Acid ...................... 26 Thioacrylamide and Chloroacetal with Anhydrous Oxalic Acid ........................... 26 Thioacrylamide and (phloroacetal in Ethanol (Acid Catalyzed) ......................... 27 Thiomethacrylamide and Chloroacetal with Anhydrous Oxalic Acid ............................ 27 Thiomethacrylamide and Chloroacetal in Dimethylformamide, ...................28 Thioacrylamide and Cyclopentadiene ........................ 28 Thiomethacrylamide and Cyclopentadiene ........... 28 iv V TABLE OF CONTENTS - - (Continued) Page Thiomethacry 1-amide with Hydrochloric Acid in E th a n o l ............................................. 29 Base-Catalyzed Polymerization of Thioacrylam ide ................. 29 Base-Catalyzed Polymerization of Thiomethacrylamide . 30 REFERENCES .......................................................................................31 LIST OF TABLES Table Page 1. Summary of Attempts to Synthesize Vinyl and 2-Isopropenyl Thiazoles ...................... 11 vi ABSTRACT Reaction of acrylamide with phosphorus pentasulfide in chloro form yields thioacrylamide (I, 45. 9%). Under the same conditions methacrylamide yields thiomethacrylamide (II, 44%). When reacted with chloroacetaldehyde or chloroacetaldehyde diethyl acetal, both thioamides failed to yield thiazoles. CH =NH I II Polymerization of (II) with potassium t-butoxide yielded pri marily simple vinyl polymer. Polymerization of (I) under the same conditions yielded a polymer of undetermined structure. INTRODUCTION Until recently, the most widely studied vinyl monomers and polymers were those of styrene and its derivatives. These studies have yielded much information concerning the effect of substituents on the double bond on monomer reactivity. The most direct means of determining monomer reactivity is through copolymerization experi ments, whereby the tendency of the active chain end, whether it be radical, carbonium ion, or carbanion, to add to its own monomer or the second monomer can be measured. Assuming the following reactions to take place during a copolymerization 11 -M • + M -M. + M2 -m 2- 2T -Mg' + M -M - -m 2-+ m 2 -M2- and defining M and M9 as monomer 1 and monomer 2, respectively, ku k22 r i aS ” k ------' and Tg as — ----- , the copolymer composition equation 12 21 dMt M l r 1[M1] + [M2]" Im J dM2 M2 r 2[M2 J + 1 provides for the determination of the desired relative reactivities. Much interest has been shown in monomers related to styrene, that is, in monomers containing ring structures which can exhibit aromatic character similar to benzene. In an extensive study of such compounds, Koton* found that the introduction of a heteroatom into the ring usually causes a marked increase in monomer reactivity. Re activity is further enhanced if a condensed ring structure is present. Co polymerizing 2-vinyl pyridine (I), 2 -vinylthiophene (II), 2-vinyl- furan (III), 2-vinyl quinoline (IV), 2-vinyl benzofuran (V), 2-vinyldibenzothiophene (VI), and 2 -vinyldibenzofuran (VII) with styrene as Mg, he found the heterocyclic monomer to be more reactive than styrene itself in all cases except 2-vinylfuran, as indicated by r^ values greater than one, and r^ values less than one. CH = CH, -CH = CHr CH = CHr S O' I II III CH = CHr CH = CH IV CH = CH CH = CH, In addition, Koton found that monomers containing condensed ring structures were more reactive than those containing only one ring. 2 Koton's results substantiate those reported earlier by Walling on vinyl pyridine and vinyl thiophene. While the trend toward increased reactivity of heterocyclic monomers is not confined to copolymerization with styrene, the use of other monomers as yields results not quite as consistent. 3 4 Frank ’ showed that while 2-, 3-, and 4-vinyl pyridine and several alkylated derivatives of these copolymerize faster with butadiene than does styrene, 2-vinylfuran, and 2-vinylthiophene copolymerize slower 5 than styrene with the same comonomer, and Kamenar found.that the copolymerization of 2-vinylfuran with vinylidene chloride proceeded at a slower rate than did the ho mo polymerization of either monomer. In the case of the 2-vinylthiophene-butadiene system, however, Meehan^ showed that, while the copolymerization proceeded at a slower rate than did the styrene -butadiene system,. 2 - vinyl thiophene enters the chain at a faster rate than , does styrene, since butadiene - styrene (75:25) copolymers at 70-80% conversion have styrene constants of 20.3-21.2%, while 2-vinyl thiophene enters the copolymer at a rate approxim.ately proportional to its concentration, in the monomer mix ture (25%). The furan ring apparently deactivates the vinyl group in 7 copolymerization reactions. Borrows studied the effect of furan analogs of einnamonitrile on the polymerization of styrene, and found that these compounds inhibit the polymerization in the presence of air and retard in the absence of air. Koton* also found that the properties of vinyl furan homopolymers are dependent on the availability of molecular oxygen. In the presence of oxygen, a soft, low melting polymer was obtained, while in the absence of oxygen, free radical initiation.yielded a hard, infusible polymer., Koton proposed that, in this case, the double bonds in the furan also polymerize, forming a three-dimensional, highly cross-linked polymer. The addition of a second or third heteroatom further enhances activity, as has been shown by the copolymerization of styrene with 2, 4-dimethyl-6-vinyl-s-triazine and 2 - dim ethyl amino- 4 -vinylpy rim i - 8 dine. Another area of interest in the study of vinyl heterocycles, is that of biological activity. Although there are a great many naturally- occurring polymers which exhibit biological activity, notably the proteins and nucleic acids, these are classified as condensation poly mers, and vinyl polymers exhibiting similar activity are rare, if indeed, existent at all. Some synthetic vinyl polymers, however, do show biological activity. Polyvinyl pyrrolidone (VIII) has been used in the preparation g . of synthetic blood plasma , although the reasons for its effectiveness 5 are incompletely understood. VIII There exists the possibility, however, that if vinyl polymers could be prepared containing substituent groups sim ilar to those consi dered to be the active site in biologically active compounds, the polymers themselves might show biological activity. But it has been shown that similarity in structure does not in itself guarantee