反应详情

A mixture of 2,2-diethoxy-1-(4-fluorophenyl)ethanone (5.2 g, 23 mmol), semicarbazide hydrochloride (2.6 g, 24 mmol) in ethanol (50 mL) was stirred overnight at ambient temperature and then heated to 80° C. for 5 hours. The reaction mixture was concentrated and the resulting residue was dissolved in acetic acid (50 mL) which was heated to 130° C. for 6 h. After cooling, the mixture was concentrated under reduced pressure. The residue was triturated with ethyl ether, filtered, and washed with diethyl ether and then hexanes. The crystalline material was collected and dried under high vacuum to give the desired product. (4.2 g, 96%) LCMS: (M+H)=192.1.

1. temperatureheated to 80° C. for 5 hours
2. concentrationThe reaction mixture was concentrated
3. dissolutionthe resulting residue was dissolved in acetic acid (50 mL) which
4. temperaturewas heated to 130° C. for 6 h
5. temperatureAfter cooling
6. concentrationthe mixture was concentrated under reduced pressure
7. customThe residue was triturated with ethyl ether
8. filtrationfiltered
9. washwashed with diethyl ether
10. customThe crystalline material was collected
11. customdried under high vacuum