Water → HCID 21487715, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 12.4 g of 4-(o-fluorophenyl)-6-methyl-1,2-dihydrothieno[2,3-d]pyrimidin-2-one in 248 ml of dimethylformamide is added 2.58 g of 67% sodium hydride. After stirring at 50°C for 1 hour and cooling to room temperature, 20.45 g of methyl iodide in 61.4 ml of dimethylformamide is added dropwise thereto. The mixture is stirred at room temperature for 1 hour, then poured into water and extracted with chloroform. The chloroform extracts are washed with water, dried over sodium sulfate, and the solvent is removed under reduced pressure. The residue is chromatographed on silica gel using chloroform as an eluent to give 1-methyl-4-(o-fluorophenyl)-6-methyl-1,2-dihydrothieno[2,3-d]pyrimidin-2-one as crystals having a melting point of 119° - 121°C (after recrystallization from chloroform-ethanol), and 3-methyl-4-(o-fluorophenyl)-6-methyl-3H-thieno[2,3-d]pyrimidin-2-one as crystals having a melting point of 239° - 241°C.

Provenance & Evidence