Microwave assisted synthesis of barbituric and thiobarbituric acid derivatives

Abstract

The parent barbituric acid and 2-thiobarbituric acid are convenient starting compounds for the preparation of different fused heterocycles and 5-substituted derivatives which are pharmacologically one of the most important classes of burbituric acid based compounds. 5-Substituted barbituric acid and thiobarbituric acid derivatives-(7,11-diphenyl and substituteddi-phenyl-2-oxo/thioxo-1,3-diazaspiro[5,5]undecane-4,6,9- triones),(5a-f), (Scheme -1) were synthesized in excellent yields by the condensation of diarylidene / substituted diarylidene acetones (3a-c) and barbituric or thiobarbituric acids in the presence of ethanol under microwave irradiation in solvent free condition. They are important class of hypnotic and sedative compounds ....................