Dicyclohexylcarbodiimide → 3-Methyl-5-(trifluoromethyl)dihydropyrimidine-2,4(1H,3H)-dione

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence