反应详情

A solution of benzyl (3-formyl-2-methylphenyl)carbamate (8.00 g, 29.7 mmol), nitroethane (10.7 ml, 149 mmol), and ammonium acetate (11.5 g, 149 mmol) was heated in an oil bath at 95° C. overnight. The reaction mixture was concentrated under reduced pressure, and the residue was diluted with a mixture of dichloromethane (150 mL) and water (75 mL) and basified with solid sodium bicarbonate slowly. The organic layer was collected, and the aqueous layer was extracted with dichloromethane (2×100 mL). The combined organic layers were dried over anhydrous sodium sulfate. Concentration under reduced pressure followed by purification by flash silica gel chromatography using a mixture of ethyl acetate in hexane (20%-35%-50%-65%-75%) afforded benzyl (2-methyl-3-(2-nitroprop-1-en-1-yl)phenyl)carbamate (5.16 g, 15.8 mmol, 53% yield) as a pale yellow solid.

1. concentrationThe reaction mixture was concentrated under reduced pressure
2. additionthe residue was diluted with a mixture of dichloromethane (150 mL) and water (75 mL)
3. customThe organic layer was collected
4. extractionthe aqueous layer was extracted with dichloromethane (2×100 mL)
5. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
6. concentrationConcentration under reduced pressure
7. customfollowed by purification by flash silica gel chromatography
8. additiona mixture of ethyl acetate in hexane (20%-35%-50%-65%-75%)