反应详情

4-Acetylamino-6-(4-chloro-2-fluoro-3-methoxyphenyl)-3-methylpyridine-2-carboxylic acid methyl ester (369 mg, 1.0 mmol) was dissolved in methanol (10 mL) and acetyl chloride (1.07 mL, 15 mmol) was added. The reaction mixture was stirred overnight at ambient temperature and concentrated under vacuum. The residue was partitioned between ethyl acetate and aqueous sodium bicarbonate; and the organic phase was dried and concentrated. Purification by flash chromatography on silica gel (dichloromethane/ethyl acetate gradient) followed by a second purification by flash chromatography (hexane/ethyl acetate gradient) yielded the title compound (292 mg, 88% yield) as a white solid, mp 122-125° C. 1H NMR (CDCl3) δ 7.65 (m, 1H), 7.26 (s, 1H), 7.1 (m, 1H), 4.35 (br s, 2H), 3.99 (s, 3H), 3.98 (d, 3H), 2.31 (s, 3H).

1. concentrationconcentrated under vacuum
2. customThe residue was partitioned between ethyl acetate and aqueous sodium bicarbonate
3. customand the organic phase was dried
4. concentrationconcentrated
5. customPurification by flash chromatography on silica gel (dichloromethane/ethyl acetate gradient)
6. customfollowed by a second purification by flash chromatography (hexane/ethyl acetate gradient)