反应详情

A solution of 4-chloro-5-bromo-2-picoline-N-oxide (23.9 g) in dichloromethane (250 ml) was cooled to 10° and trifluoroacetic anhydride (25 ml) added over 20 minutes. The mixture was allowed to warm to ambient temperature, and stand for 7 days. After cooling to 10°, methanol (100 ml) was added, and the solution stripped. The residue was treated with water (150 ml), basified with saturated aqueous sodium carbonate to pH 10, and extracted with ethyl acetate (2×150 ml). The combined extracts were dried (MgSO4). stripped, and triturated with ether to give 4-chloro-5-bromo-2-hydroxymethylpyridine, 16.58 g. m.p. 109°-10°.

1. temperatureAfter cooling to 10°
2. extractionextracted with ethyl acetate (2×150 ml)
3. dry with materialThe combined extracts were dried (MgSO4)
4. customtriturated with ether