反应详情

To a stirred solution of methyl 4-butyl-3,4-dihydro-2H-1,4-benzoxazine-6-carboxylate (412 mg) in methanol (5 mL) was added 1 M potassium hydroxide (17 mL). The mixture was stirred at room temperature for 5 h and concentrated under reduced pressure. The residue was diluted with water and washed with ethyl acetate. The aqueous layer was acidified to pH 4 with 1 N hydrochloric acid and extracted with chloroform (4×50 mL). The combined organic extracts were dried (sodium sulfate), filtered, and concentrated under reduced pressure to provide 384 mg of the title compound: ESI MS m/z 236 [M+H]+.

1. concentrationconcentrated under reduced pressure
2. additionThe residue was diluted with water
3. washwashed with ethyl acetate
4. extractionextracted with chloroform (4×50 mL)
5. dry with materialThe combined organic extracts were dried (sodium sulfate)
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure