4-Toluenesulfonyl chloride → 3-Cyclopropyl-1-(2-fluoro-4-iodophenyl)-6,8-dimethyl-5-(((4-methylphenyl)sulfonyl)oxy)pyrido(2,3-d)pyrimidine-2,4,7(1H,3H,8H)-trione

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Reaction Steps

Under a nitrogen atmosphere, to 3-cyclopropyl-1-(2-fluoro-4-iodo-phenyl)-5-hydroxy-6,8-dimethyl-1H,8H-pyrido[2,3-d]pyrimidine-2,4,7-trione 55 (23.9 g) was added acetonitrile (167 ml), and the mixture was stirred under ice-cooling. Triethylamine (11.0 ml) and trimethylamine hydrochloride (2.37 g) were added, and a solution of p-toluenesulfonyl chloride 11 (12.3 g) in acetonitrile (72.0 ml) was added dropwise. The mixture was stirred under ice-cooling for 1 hr, and stirred at room temperature for 3 hrs. Methanol (239 ml) was added, and the mixture was stirred at room temperature for 1 hr. The crystals were collected by filtration and dried to give p-toluenesulfonic acid 3-cyclopropyl-1-(2-fluoro-4-iodo-phenyl)-6,8-dimethyl-2,4,7-trioxo-1,2,3,4,7,8-hexahydro-pyrido[2,3-d]pyrimidin-5-yl ester 77 (28.7 g, yield 91%) as colorless crystals.

Provenance & Evidence