Synthesis of 2,5-disubstituted 1,3,4-oxadiazoles containing a sterically hindered 4-hydroxy-3,5-di(tert-butyl)phenyl group

A series of 2,5-disubstituted 1,3,4-oxadiazoles containing one or two 4-hydroxydi(tert-butyl)phenyl groups has been synthesized. These sterically hindered compounds were prepared by condensation of acids containing the indicated fragment and their derivatives with hydrazine dihydrochloride, hydrazides, and hydrochlorides of iminoesters of acids, by the reaction of 4-hydroxy-3,5-di(tert-butyl)thiphenol with 2-chloromethylsubstituted 1,3,4-oxadiazoles in the presence of KOH, and by cyclodehydration of N-acyl-N-4-hydroxy-3,5-di(tertbutyl)benzoyl]hydrazones under action of POCl₃.I. M. Gubkin State Oil and Gas Academy, Moscow 117917. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 822–828, June, 1997.