Reaction of Benzoyl Isothiocyanate With Active Methylene Reagents: A Convenient Synthesis of Pyrazolo[5,4-<i>c</i>]pyrazole, 1,3-Oxazine, Thiazole and Pyrimidine Derivatives

Abstract

Benzoyl isothiocyanate reacts with active methylene reagents e.g. ethyl cyanoacetate, malonitrile and acetylacetone to give, in each case, the corresponding 1:1 adduct 1, 13 and 14 respectively, Compound 1 was utilized for the synthesis of several heterocyclic derivatives. Compound 14 undergoes ready cyclization in basic medium to give the 1,3-oxazine derivative 15. The structures of the products were assigned and confirmed on the basis of their elemental analysis and spectral data.