New heterocyclic compounds from 1,2,4-trizoles and 1,3,4-oxadiazoles class containing 5H-dibenzo[a,d][7]annulene moiety

In this paper we present the synthesis of the new heterocyclic compounds with 5H-dibenzo[a,d][7]annulene moiety obtained by cyclization of 2-acylhydrazinecarbothioamides (2a,b). The acylhydrazinecarbothioamides were obtained by treating 2-(5H-dibenzo[a,d][7]annulen-5-yl)acetohydrazide (1) with 2,5-difluorophenyl or 3-bromophenyl isothiocyanates. 2-Amino-1,3,4-oxadiazoles (3a,b) were synthesized by cyclization of 2- acylhydrazinecarbothioamides in the presence of mercury oxide. The new 1,2,4-triazole-3-thioles (4a,b) were synthesized by cyclization, in alkaline media, of the corresponding acylhydrazinecarbothioamide. The structures of the new compounds synthesized were investigated by 1H-NMR, 13C-NMR, IR and elemental analysis.