Synthesis of Bis{(S‐methyl)azolespoly(ethylene oxide)} from 3,6‐dioxa‐1,8‐octanedithiol

Abstract

Bis(1,3,4‐oxadiazoles) 4, 5 and bis(1,2,4‐triazoles) 6a, 6b have been prepared from 3,6‐dioxa‐1,8‐octanedithiol 1 through a multistep reaction sequence. Compound 4 reacted with the appropriate alkyl halide in the presence of potassium carbonate in refluxing acetone to give the corresponding bis(S‐alkylated‐1,3,4‐oxadiazoles) 7a, 7b. The title compound 8 was prepared by condensing 4 with benzoyl bromide in the presence of triethylamine. Further, 6,9‐dioxa‐3,12‐dithiotetradecanedihydrazide 3 was converted to bis{N′‐(phenylaminocarbonyl) hydrazides} and bis{N′‐(phenylaminocarbonothioyl)hydrazides} 9a, 9b using phenylisocyanate and phenylthioisocyanate, respectively, which underwent cyclization in alkaline medium to produce 6,9‐dioxa‐3,12‐dithiotetradecane bis(4‐phenyl‐2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐one) and their 3‐thio analogs 10a, 10b. The new compounds 4, 5, 6, 7, 8, 9, 10 were characterized by their IR, 1H‐NMR, 13C‐NMR, MS, and elemental analyses.