反应详情

To a solution of ethyl acetoacetate (compound 7, 30 g, 0.23 mol) in acetic acid (35 mL) was added slowly sodium nitrite (18.0 g, 0.25 mol) in cold water (40 mL) at −10° C. The reaction mixture was stirred for 1 hr, then added cold water (120 mL) and stirred for 3 hrs. The mixture was extracted with diethyl ether (300 mL). The organic layer was washed with saturated NaHCO3 (400 mL×2), then dried over anhydrous MgSO4, filtered and concentrated in vacuo. The obtained product (21.46 g, white solid) was used for the next step without purification.

1. stirringstirred for 3 hrs
2. extractionThe mixture was extracted with diethyl ether (300 mL)
3. washThe organic layer was washed with saturated NaHCO3 (400 mL×2)
4. dry with materialdried over anhydrous MgSO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe obtained product (21.46 g, white solid) was used for the next step without purification