反应详情

To a solution of methyl 4-amino-3-fluoro-2-((2-fluorophenyl)amino)-5-mercaptobenzoate in trimethyl orthoformate (50 mL) was added p-TsOH (0.61 g, 3.17 mmol). The reaction mixture was stirred for 1 h and treated with water (100 mL). The precipitate was filtered off and the filter cake was washed with water to afford the desired product (pale yellow solid, 8.64 g, 85.1% yield for two steps). 1H NMR (400 MHz, CDCl3): δ 9.13 (s, 1H), 8.68 (s, 1H), 8.46 (s, 1H), 7.10 (m, 1H), 7.01 (m, 1H), 6.92 (s, 2H), 3.97 (s, 3H).

1. filtrationThe precipitate was filtered off
2. washthe filter cake was washed with water