反应详情

A mixture of 70% aqueous ethylamine (0.46 g) and dichloromethane (5 ml) was cooled, with stirring, in an ice bath. A solution of the acid chloride (1.05 g; prepared as described in part (a) above) in dichloromethane (5 ml) was added and the mixture was stirred for 7 hours and then allowed to stand overnight. After this time thin layer chromatography indicated that the reaction had not gone to completion and therefore a further portion of 70% aqueous ethylamine was added and the mixture was heated under reflux for a period of 3 hours. The mixture was allowed to cool, made up to 30 ml with dichloromethane and was washed with water (4×20 ml). The organic phase was dried over anhydrous magnesium sulfate and the solvent removed by evaporation. The solid residue was purified by preparative thin layer chromatography on silica gel (eluent dichloromethane/isopropyl alcohol 20:1) to give the title compound (0.74 g), mp 141°-142° C. The pmr spectrum of the compound was consistent with the assigned structure.

1. temperaturewas cooled
2. stirringthe mixture was stirred for 7 hours
3. temperaturethe mixture was heated
4. temperatureunder reflux for a period of 3 hours
5. temperatureto cool
6. washwas washed with water (4×20 ml)
7. dry with materialThe organic phase was dried over anhydrous magnesium sulfate
8. customthe solvent removed by evaporation
9. customThe solid residue was purified by preparative thin layer chromatography on silica gel (eluent dichloromethane/isopropyl alcohol 20:1)