Synthesis of novel 1-[(1-ethoxymethylene)amino]imidazol-5(4H)-ones and 1,2,4-triazin-6(5H)-ones from optically active α-aminocarboxylic acid hydrazides

New derivatives of 1-[(1-ethoxymethylene)amino]imidazol-5(4H)-one and 1,2,4-triazin-6(5H)-one were synthesized via reactions of optically active α-aminocarboxylic acid hydrazides and triethyl orthoesters in xylene. The factors influencing the formation of the unexpected five-membered products and attempts to elucidate the mechanism are discussed.