反应详情

A solution of the product of step (a) (2.9 g, 7.6 mmoles) and methyl 3-amino-4-fluoro-2-butenoate (1 g, 7.6 mmoles) in dry tert-butanol (20 ml) was heated to 60° (oil bath temperature) for 16 hours. The solution was allowed to cool to room temperature and the solvent removed in vacuo. Chromatography on silica, eluting with dichloromethane/ethyl acetate mixtures afforded the title compound as an oil which crystallised on addition of petroleum ether (60°-80° ). The solid was recrystallised from petroleum ether (60°-80° )/acetone to afford the title compound 1.03 g, mp 155°-6°.

1. customthe solvent removed in vacuo
2. washChromatography on silica, eluting with dichloromethane/ethyl acetate mixtures