反应详情

(2-Fluoro-6-trifluoromethyl-benzyl)-urea (2.568 g, 10.9 mmol) in toluene (125 mL) was heated briefly to reflux under a Dean-Stark trap. T-butyl acetoacetate (5.0 g) was added and the mixture heated to reflux for 4 hrs. p-Toluenesulfonic acid monohydrate (2.82 g, 14.8 mmol) was added and the reflux was continued for one additional hour. Toluene was displaced with i-PrOH and the volume of the solution was reduced to approximately 30 mL. The solution was stirred overnight at room temp. The crystalline product was filtered and washed with a few mL of i-PrOH to provide 2.01 g (63% yield) of 1-(2-fluoro-6-trifluoromethyl-benzyl)-6-methyl-1H-pyrimidine-2,4-dione. LCMS (ESI) m/z 303.0 (MH+)

1. temperatureto reflux under a Dean-Stark trap
2. temperaturethe mixture heated
3. temperatureto reflux for 4 hrs
4. filtrationThe crystalline product was filtered
5. washwashed with a few mL of i-PrOH