反应详情

A solution of 4-(4-cyano-2-(2,6-difluorophenyl)oxazol-5-ylamino)benzoic acid (0.962 g, 2.819 mmol) in concentrated sulfuric acid (5 mL) was stirred at room temperature for 1.5 hours. The reaction mixture was added to ice water and a precipitate formed. The precipitate was isolated by filtration and the remaining aqueous layer extracted with ethyl acetate. The organic layer was combined with the precipitate and reduced in vacuo to yield 4-(4-carbamoyl-2-(2,6-difluorophenyl)oxazol-5-ylamino)benzoic acid (0.580 g, 1.614 mmol, 57%) as a yellow solid. 1H NMR (DMSO) δ 7.35 (2H, t), 7.46 (4H, m), 7.65 (1H, m), 7.87 (2H, d), 9.71 (1H, s), 12.64 (1H, br s). LCMS (2) Rt: 1.37 min; m/z (ES+) 360.

1. customa precipitate formed
2. customThe precipitate was isolated by filtration
3. extractionthe remaining aqueous layer extracted with ethyl acetate