反应详情

2-Chloro-nicotinic acid ethyl ester (4.55 g, 24.6 mmol), O-benzylhydroxyamine hydrochloride (7.85 g, 49.2 mmol) and N,N-diisopropylethylamine (6.36 g, 49.2 mmol) in 10 mL 1,4-dioxane were reacted in a sealed tube at 120° C. for 48 hours. The reaction mix was partitioned between ethyl acetate and 5% aqueous sodium bicarbonate. The aqueous layer was re-extracted with ethyl acetate (2×50 mL). The organic layers were combined and dried over sodium sulfate, filtered, and concentrated. The residue was purified by column chromatography on silica gel eluting with hexane and ethyl acetate (9:1) to provide the title compound (3.5 g, 53%). MS (DCI) m/z 273 (M+H)+.

1. additionThe reaction mix
2. customwas partitioned between ethyl acetate and 5% aqueous sodium bicarbonate
3. extractionThe aqueous layer was re-extracted with ethyl acetate (2×50 mL)
4. dry with materialdried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue was purified by column chromatography on silica gel eluting with hexane and ethyl acetate (9:1)