Triethyl Phosphate → Allyl(rac)-4-[4-cyano-2-(methylsulfonyl)phenyl]-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. Triethyl phosphate (22.98 g, 126 mmol) and diphosphorus pentoxide (11.94 g, 84.1 mmol) were stirred at 50° C. overnight. The mixture was then diluted with MTBE (450 ml), and 4-formyl-3-(methylsulfonyl)benzonitrile (22.00 g, 105 mmol; Example 4A), 1-[3-(trifluoromethyl)phenyl]urea (21.47 g, 105 mmol) and allyl acetoacetate (22.42 g, 158 mmol) were added. The mixture was stirred under reflux overnight. Since the reaction was incomplete, the reaction mixture was concentrated by distillative removal of 350 ml of MTBE. The mixture was then heated under reflux for a further 4 h. For work-up, the solvent was removed under reduced pressure, and the residue was suspended in diethyl ether and then filtered off with suction. The solid was washed with dist. water (350 ml) and then with diethyl ether (50 ml). This gave 34.74 g (64% of theory) of the title compound.

Provenance & Evidence