芳香胺参加的Mannich反应 Ⅲ.4-甲基喹啉类化合物的合成

MANNICH REACTION WITH ARYLAMINE AS THE AMINE COMPONENT—(Ⅲ)SYNTHESIS OF LEPIDINE AND ITS DERIVATIVES

用Skraup,Doebner-Miller,Baeyei等法制备喹啉类化合物时,它们的中间化合物都是β-芳胺基酮。这已为文献[1、2]等的工作所证明。从结构来看,这类酮是Mannich碱。但以往囿于芳香胺不能参加Mannich反应的偏见。

Lepidine and its derivatives were prepared by Mannich reaction with arylamine as the amine component and cyclization. Mannich reaction was carried out directly between arylamine hydrochloride, 37％ formaldehyde and acetone by the following method:to arylamine dissolved in ethyl alcohol, a solution of ethanolic-HCl was added, then added 37% formaldehyde and acetone, and the mixture thus obtained was allowed to stand a few hours or over night at room temperature, 4-arylaminobutan2-one was formed. Without separating the 4-arylaminobutan-2-one, FeCl_3·6H_2O and ZnCl_2 were added, the mixture was stirred and heated 4 hours at 85—90℃.4-arylaminobutan-2-one was cyclized to lepidines in moderate yield.