Dicyclohexylcarbodiimide → 1-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 (378 mg; 5.1 mmoles) in DMF (5 ml) was cooled to 0° C., and a solution of DCC (1.07 g; 5.2 mmoles) in DMF (3 ml) was added dropwise. The mixture was stirred for 1 hour, and the precipitated solid was filtered off and washed with ethyl acetate. DMF 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 420 mg (yield: 43%) of 1-methyl-5-trifluoromethyl-5,6-dihydrouracil (OF-3) and 30 mg (yield: 15%) of 3-methyl-5-trifluoromethyl-5,6-dihydrouracil (OF-2).

Provenance & Evidence