Triethyl Phosphate → (rac)-Allyl 4-(4-cyano-2-nitrophenyl)-6-methyl-2-oxo-1-[3-(trifluoromethyl)phenyl]-1,2,3,4-tetrahydropyrimidine-5-carboxylate

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Reaction Steps

The reaction was carried out under argon. Allyl acetoacetate (5.94 g, 41.5 mmol; 1.0 eq.) was initially charged in THF (117 ml) at RT. Subsequently, 4-cyano-2-nitrobenzaldehyde (10.45 g, 41.5 mmol, purity 70%; 1.0 eq.), 1-[3-(trifluoromethyl)phenyl]urea (8.48 g, 41.5 mmol) and triethyl phosphate (17.7 g) were added. The mixture was stirred under reflux for 16 h. For work-up, initially ice-water was added, and the mixture was then taken up in ethyl acetate (400 ml). The organic phase was dried over solid sodium sulfate, filtered and concentrated under reduced pressure. The crude product was recrystallized from hot water/isopropanol (2:1, ˜400 ml). The solid obtained was triturated with diethyl ether (60 ml), once more filtered off with suction, washed with a little diethyl ether and dried under high vacuum. The title compound was obtained as a solid (16.63 g, 82% of theory).

Provenance & Evidence