Synthesis of 7,11-diaryl-3-oxo (or thioxo)-2,4-diazaspiro[5.5]undecane-1,5,9-triones, Part I

Spiro compounds 7,11-diaryl-2,4-diazaspiro[5.5]undecane-1,3,5,9-tetraones 3a–e and 7,11-diaryl-3-thioxo-2,4-diazaspiro[5.5]undecane-1,5,9-triones 3f–j were prepared from the reaction of 1,5-diaryl-1,4-pentadien-3-ones 2a–f with barbituric acid (1a) and 2-thiobarbituric acid (1b). The structures of the products were confirmed by UV, IR, 1 H and 13 C NMR, MS and elemental analysis.