1-Amino-3-[4-cyano-3-methoxyphenyl]-6-trifluoromethyl-1,2,3,4-tetrahydropyrimidine-2,4-dione → 1-Amino-3-[4-cyano-3-hydroxyphenyl]-6-trifluoromethyl-1,2,3,4-tetrahydropyrimidine-2,4-dione

Participants

Reaction Steps

1-Amino-3-[4-cyano-3-methoxyphenyl]-6-trifluoromethyl-1,2,3,4-tetrahydropyrimidine-2,4-dione (2.0 g) and pyridinium hydrochloride (2.1 g) were stirred for 2 hours at 200-210° C. After cooling, the reaction mixture was dissolved in 100 ml of n-butanol, whereupon the solution was washed three times using in each case 30 ml of water. The organic phase was dried over sodium sulfate and subsequently freed from solvent. After crystallization using 10 ml of diisopropyl ether and chromatographic purification of the crude product (eluent: dichloromethane/ethyl acetate=9:1 to 1:1), 0.4 g of the desired product was obtained. M.p.: >230° C.

Provenance & Evidence