Sodium hydride → 3-(2,6-difluoro-3,5-dimethoxy-phenyl)-1-ethyl-7-methylsulfanyl-3,4-dihydro-1H-pyrimido[4,5-d]pyrimidin-2-one

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Reaction Conditions

Reaction Steps

A solution of 4.92 g (11.58 mmol) of (5-[(2,6-difluoro-3,5-dimethoxy-phenylamino)-methyl]-2-methylsulfanyl-pyrimidin-4-yl)-ethyl-amine in 85 mL of anhydrous tetrahydrofuran was cooled to 0° C. using an ice/acetone bath. The reaction mixture was treated with 1.16 g (28.95 mmol) of sodium hydride and continued stirring at 0° C. for 30 minutes. After 30 minutes, 5.63 g (34.74 mmol) of 1,1′-carbonyldiimidazole was added and continued to stir at 0° C. for an additional 30 minutes. After 1 hour, the ice bath was removed and the reaction mixture was allowed to warm up to room temperature. The reaction mixture heated at reflux overnight under nitrogen atmosphere. Evaporated the tetrahydrofuran and partitioned the residue between dichloromethane and water. The aqueous layer was extracted one time with 250 mL dichloromethane. The dichloromethane extracts were combined, dried over sodium sulfate, filtered and evaporated. The crude product was purified using medium-pressure chromatography eluting with 2:1 hexanes/ethyl acetate to give 4.23 g (92%) of the title compound: mp 165° C.–168° C. MS (APCI) (m+1)/z 397.1.

Provenance & Evidence