反应详情

温度

80 °C

A mixture of α-trifluoromethylacrylic acid (700 mg; 5.0 mmoles) and methylurea (370 mg; 5.0 mmoles) in DMF (5 ml) was heated at 80° C. with stirring for 3 hours. After cooling to 0° C., a solution of dicyclohexylcarbodiimide (DCC) (1.05 g; 5.1 mmoles) in 3 ml of DMF was added dropwise. The mixture was stirred for 1 hour, and the precipitated solid was filtered off and washed with ethyl acetate. The solvent was evaporated under reduced pressure from the combined filtrates. The residue was purified by a column chromatography on silica gel (ethyl acetate:chloroform=1:3) to give 424 mg (yield: 43%) of 3-methyl-5-trifluoromethyl-5,6-dihydrouracil (OF-2) and 174 mg (yield: 18%) of 1-methyl-5-trifluoromethyl-5,6-dihydrouracil (OF-3).

1. temperatureAfter cooling to 0° C.
2. stirringThe mixture was stirred for 1 hour
3. filtrationthe precipitated solid was filtered off
4. washwashed with ethyl acetate
5. customThe solvent was evaporated under reduced pressure from the combined filtrates
6. customThe residue was purified by a column chromatography on silica gel (ethyl acetate:chloroform=1:3)