- A novel convenient synthesis of 1,3,4-oxadiazol-2-ones and -thiones from N-tert-butyldiacylhydrazines
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An attractive, novel, convenient process for the preparation of 3,5-disubstituted-3H-[1,3,4]-oxadiazol-2-ones and -thiones from the reaction of various equivalent and non-equivalent N-tertbutyldiacylhydrazines with potassium tert-butoxide followed by treatment with phosgene or thiophosgene, respectively, has been discovered. The 3,5-disubstituted-3H-[1,3,4]-oxadiazol-2-ones and -thiones are confirmed both analytically and chemically. Various equivalent and non-equivalent N-tert-butyldiacylhydrazines are conveniently synthesized from the reaction of tert-butylhydrazine hydrochloride in the presence of i-Pr2NEt, with acid chloride #1 followed by subsequent treatment with acid chloride #2. Both the syntheses of 3,5-disubstituted-3H-[1,3,4]-oxadiazol-2-ones and -thiones, as well as N-tert-butyldiacylhydrazines, are easily performed on multigram scales.
- Mulvihill,Nguyen,MacDougall,Weaver,Mathis
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p. 1965 - 1970
(2007/10/03)
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- 3,3'-Carbonylbis: A Novel, Reactive, and Versatile Condensing Agent for Amide, Ester, Thiol Ester, Urea, Carbonate, Polyamide, and Polyurea Syntheses
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A novel condensing agent, 3,3'-carbonylbis (3), was readily prepared by the reaction of 5-phenyl-1,3,4-oxadiazole-2(3H)-thione with trichloromethyl chloroformate in benzene.The reagent 3 was found to be very useful for the one-pot or direct preparation of amid, ester, thiol ester, uea, and carbonate under mild conditions.The one-pot or direct polycondensation of several dicarboxylic acids with aromatic diamines and of aromatic diamines using 3 proceeded smoonthly at ambient temperature to produce high-molecular-weight polyamides and polyureas, respectively.
- Saegusa, Yasuo,Watanabe, Tatsushi,Nakamura, Shigeo
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p. 539 - 544
(2007/10/02)
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