Publication Date
2016
Document Type
Thesis
Committee Members
William Feld (Committee Member), Eric Fossum (Committee Member), Kenneth Turnbull (Advisor)
Degree Name
Master of Science (MS)
Abstract
Various 1,3,4-oxadiazol-2(3H)-ones were synthesized by reaction of the bromocarbonylhydrazine salt(35) obtained from treatment of 4-bromo-3-phenylsydnone(34) with HCl with the corresponding acid chlorides in DME. The structures were confirmed by their physical, analytical and spectral data (IR, GC/MS, 1H and 13C NMR and CHN analysis). In general these compounds were synthesized in good to excellent yields and it is planned to continue exploration of their chemical behavior as a guide to their potential antimicrobial activity. As an initial approach to the synthesis of the desired 1,3,4-oxadiazol-2(3H)-ones, the starting material, 3-phenylsydnone, was prepared in 2 steps from commercially available N-phenylglycine in good overall yield. This sydnone was then converted into the versatile intermediate, 4-bromo-3-phenylsydnone. The latter was then converted by treatment with hydrochloric acid into the bromocarbonylhydrazine salt(35), which served as a key synthon for the preparation of a wide variety of 3,5-disubstituted oxadiazolinones. With respect to the cyclization step, the bromocarbonylhydrazine salt(35) was treated with an acid chloride (alkyl version) in DME and simple work-up with ice water / extraction resulted in a facile, high yield approach to the target oxadiazolinone. However, with aryl acid chlorides the use of a subsequent base treatment was needed to remove unreacted acid chloride and provide good yields of the corresponding oxadiazolinones. With a successful avenue in hand, attempts were made to optimize the yields of the desired 1,3,4-oxadiazol-2(3H)-ones by changing several parameters such as the amount of acid chloride, the reaction temperature and the reaction time. The optimized approach was then used for the successful preparation of a number of oxadiazolinones, including one new compound, viz. 5-(3-bromophenyl)-3-phenyl-1, 3, 4-oxadiazol-2(3H)-one (49), which was obtained in 60% yield.
Page Count
68
Department or Program
Department of Chemistry
Year Degree Awarded
2016
Copyright
Copyright 2016, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
