反应详情

To an ice-cold stirred solution of methyl 4-hydroxy-3-[(1E)-N-hydroxybutanimidoyl]benzoate (170 mg, 0.7 mmol) in diethyl ether (5 mL) was added a mixture of thionyl chloride (60 μL, 0.8 mmol) and pyridine (580 μL, 7.2 mmol) in diethyl ether (5 mL). After 2.5 h the mixture was poured over ice-water and acidified to pH=1 with 1 N hydrochloric acid. The mixture was then partitioned between water and ethyl acetate. The organic layer was washed with saturated sodium bicarbonate, dried (sodium sulfate), filtered, and concentrated under reduced pressure to afford a crude oil. Purification by flash column chromatography (silica, 10:1 hexanes/ethyl acetate) provided methyl 3-propyl-1,2-benzisoxazole-5-carboxylate (90 mg): 1H NMR (300 MHz, CDCl3): δ 8.36-8.35 (m, 1H), 8.07-8.04 (m, 1H), 7.52-7.49 (m, 1H), 3.95 (s, 3H), 2.96-2.91 (m, 2H), 2.00-1.87 (m, 2H), 1.09-1.04 (m, 3H).

1. customThe mixture was then partitioned between water and ethyl acetate
2. washThe organic layer was washed with saturated sodium bicarbonate
3. dry with materialdried (sodium sulfate)
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customto afford a crude oil
7. customPurification by flash column chromatography (silica, 10:1 hexanes/ethyl acetate)