Acetic Acid → N-{3-[5-(2-fluoro-4-iodophenylamino)-3,6,8-trimethyl-2,4,7-trioxo-3,4,6,7-tetrahydro-2H-pyrido[4,3-d]pyrimidin-1-yl]phenyl}methanesulfonamide

Participants

Reaction Steps

Under ice-cooling, to a suspension of N-{3-[1-(2-fluoro-4-iodophenyl)-3,6,8-trimethyl-2,4,7-trioxo-1,2,3,4,7,8-hexahydro-pyrido[2,3-d]pyrimidin-5-ylamino]phenyl}methanesulfonamide 71 (3.10 g) obtained in Step 7 in tetrahydrofuran (31.0 ml) was added dropwise a mixture of potassium t-butoxide (1.33 g), methanol (0.482 ml) and tetrahydrofuran (15.5 ml), and the mixture was stirred under ice-cooling for 2 hrs. Acetic acid (1.36 ml) was added, the mixture was allowed to warm to room temperature and stirred for 1 hr. The reaction mixture was concentrated, methanol/water [1:2 (volume ratio), 45.0 ml] was added, and the mixture was further stirred at room temperature for 1 hr. The crystals were collected by filtration and dried to give N-{3-[5-(2-fluoro-4-iodophenylamino)-3,6,8-trimethyl-2,4,7-trioxo-3,4,6,7-tetrahydro-2H-pyrido[4,3-d]pyrimidin-1-yl]phenyl}methanesulfonamide 72 (3.01 g, yield 97%) as a pale-gray solid.

Provenance & Evidence