Síntesis de azino-bis (formaldehidodimetilditioacetales)

Abstract

It has been found that in the N'-[bis(alkylthio)methylen]cyano­acethydrazides derived from cyanoacethydrazide are present the structural requirements for the formation, in basic medium, of methylenic carbanions, which could react with different alkenes and dithiethenes through a push ­pull mechanism in order to give a series of heterocyclic compounds with po­tential biological aclivily. Before undertaking the study of such reaction it was considered of interest to find what could be the behaviour of this kind of compounds in presence of sodium ethoxide in hot temperature, in order to know the possible processes wfiich could occur during the interaction between the substrate and the base. Only a few examples similar to such reactions could be found reported in the literature and they were related to the interaction of the HC-compounds with electrophilic reagents. It was shown that in the reac­tion, rather unexpectedly, instead ofthe expected products were isolated com­pounds of the type of azino bis(formaldehydedialkyldithioacetals), in high yields, via the intra- Or intermolecular interaction of N'-[bis(alkylthio)­methylen]cyanoacethydrazides with the base. A reaction mechanism was pro­posed which explains satisfactorily the formation ofthe isolated compounds, which, in turn, were charaterized by quantitative elemental analysis and spec­troscopic techniques Infrared, ¹H and ¹³C-NMR, and mass spectrometry). The reported method for the preparation of compounds of type azino-bis(formal­dehydedialkyldithioacetals), seems to be highly conveniente because of its simplicity and the h;gh yields and purity of the products.