反应详情

6.7 g (26.8 mmol) of 2-(3-nitrobenzylidene)-acetoacetic acid methyl ester and 6.0 g (26.8 mmol) of 3-amino-crotonic acid-(7-cyanoheptyl)ester are boiled in 50 ml of isopropanol for 12 hours. The precipitate which separates is suction filtered and chromatographed on silica gel with dichloromethane/methanol (98:2). The main fraction yields 7.9 g (65%) of yellow crystals melting at 151°-152° C. after concentration of the fraction by evaporation under vacuum and recrystallisation of the residue from tert.-butyl-methyl ether.

1. filtrationfiltered
2. customchromatographed on silica gel with dichloromethane/methanol (98:2)