Synthesis of 2-Amino-4,5-dihydro-1,3-selenazol-4-ones by Reaction of N,N-Disubstituted Selenoureas with Acetylenedicarboxylate

Reaction of N,N-disubstituted selenoureas with dimethyl acetylenedicarboxylate afforded 2-amino-5-methoxycarbonylmethylene-4,5-dihydro-l,3-selenazol-4-ones in high yields. The crystal structure of 5-methoxycarbonylmethylene-2-piperidino-4,5-dihydro-1,3-selenazol-4-one was confirmed by X-Ray diffraction. Reaction of the N,N-disubstituted selenoureas with acetylenedicarboxylic acid gave 2-amino-5-carboxymethylene-4,5-dihydro-1,3-selenazol-4-ones in high yields.