反应详情

温度

80 °C

A solution of the crude (RS)-4-bromo-1-fluoro-2-(2-iodo-1-isocyanato-1-methyl-ethyl)-benzene (20.0 g, 52 mmol) in N,N-dimethylformamide (180 ml) and tert-butanol (7.7 ml, 104 mmol) was treated with silver tetrafluoroborate (11.15 g, 57 mmol). The yellow suspension was heated at 80° C. for 16 hours. For the workup, the reaction mixture was evaporated at reduced pressure. After chromatography on silica gel using a using a gradient of heptane and ethyl acetate=100/0 to 40/60 as the eluent, the (RS)-4-(5-bromo-2-fluoro-phenyl) -4-methyl-oxazolidin-2-one (intermediate C4A) was obtained as a white solid (28.49 g, 53.5% of theory).

1. customFor the workup, the reaction mixture was evaporated at reduced pressure