摘要:
A one-pot procedure was developed for the synthesis of 3-isothiocyanatopropionaldehyde and 3-isothiocyanatobutyraldehyde diethyl acetals from the corresponding alpha,beta-unsaturated aldehydes. Reactions of 1,1-diethoxy-3-isothiocyanatobutane with aliphatic amines and hydrazines gave, respectively, substituted thioureas and thiosemicarbazides which underwent acid-catalyzed cyclization to form 6-ethoxytetrahydropyrimidine-2(IH)-thiones, 9,10-dimethoxy-2-methyl-1,2,3,6,7,11b-hexahydro-4H-pyrimido[6,1-a]-isoquinoline-4-thiones, and 2-methyl-2,3,6,7,12,12b-hexahydropyrimido[1',6': 1,2]pyrido[3,4-b]indole-4(1H)-thione.