Efficient Synthesis of 2-Aroyl-3-Alkoxy-2,3-Dihydrothiazolo[2,3-c][1,2,4]Triazol-5(6H)-ones

Aryl carboxylic acid N'-(4-oxo-4,5-dihydro-thiazol-2-yl) hydrazides (4a-g) were prepared from the reactions of 2-carbethioxymethylthio-2-thiazoline-4-one (2) with alkyl or aryl hydrazides (3a-g), in ethanol at room temperature. The reactions of compounds 4a-g with methyl and ethyl orthoformates afforded 2-aroyl-3-alkoxy-2,3-dihydrothiazolo[2,3-c][ 1,2,4] triazol-5(6H)-ones (5an). All newly synthesized compounds were fully characterized using Mass spectrometry, IR, (HNMR)-H-1, C-13-NMR spectroscopy, and elemental analysis.