Synthesis of Nitrogen-Containing Heterocycles 11. 1,2,4-Triazole Formation through Disproportionation of Polyazapolyenes
摘要:
Aromatic diaminomethylenehydrazones 1-4 were reacted with bis(methylthio)methylenemalononitrile (BMM) to give 5-aryl-1-benzyl-3dimethylamino-1H-1,2,4-triazoles(5-8) via disproportionation in ftised condition in moderate to high yields (44-78 %). Little or no effect was observed on disproportionation products in connection with substituents on the benzene ring. When used an equimolar amount of two different diaminomethylenehydrazones 3 and 4, four types of 5-aryl-1-benzyl-3-dimethylamino-1H-1,2,4-triazoles were obtained. In the reaction using two (different) benzaldehyde S-methylisothiosemicarbazones 22 and 23, four types of 5-aryl-1-benzyl-3methylthio-1H-1,2,4-triazoles were formed in 14-26 % yield. The structural assignment of products and reaction mechanism are discussed.
Synthesis of Nitrogen-Containing Heterocycles 11. 1,2,4-Triazole Formation through Disproportionation of Polyazapolyenes
作者:Yoshiko Miyamoto
DOI:10.3987/com-07-11268
日期:——
Aromatic diaminomethylenehydrazones 1-4 were reacted with bis(methylthio)methylenemalononitrile (BMM) to give 5-aryl-1-benzyl-3dimethylamino-1H-1,2,4-triazoles(5-8) via disproportionation in ftised condition in moderate to high yields (44-78 %). Little or no effect was observed on disproportionation products in connection with substituents on the benzene ring. When used an equimolar amount of two different diaminomethylenehydrazones 3 and 4, four types of 5-aryl-1-benzyl-3-dimethylamino-1H-1,2,4-triazoles were obtained. In the reaction using two (different) benzaldehyde S-methylisothiosemicarbazones 22 and 23, four types of 5-aryl-1-benzyl-3methylthio-1H-1,2,4-triazoles were formed in 14-26 % yield. The structural assignment of products and reaction mechanism are discussed.