ABSTRACT

The reaction of either malononitrile or ethyl cyanoacetate with both of CS₂ and phenyl-isothiocyanate along with ethoxymethylene-nitriles or 1,1-dicyano-2-ethoxypropene using phase-transfer catalysis technique afforded the corresponding 2-thiophen-, 2-pyrrolylidene-nitriles or 2-thiopyran- and 2- pyridinylidene-nitriles in fair yields. Some of these compounds were treated with acetylacetone to afford the corresponding spiro derivatives of thiophene, thiopyrane and pyridine attached to pyrane moiety. Moreover, examples of thiophene, thiopyrane, or pyridine were allowed to react with phenacyl bromide to furnish thieno(3,4-d )pyrrole, thieno(2,3-b) thiopyrane and thieno(2,3-b)pyridine derivatives.