Water → HCID 12202396, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 9.49 g of 4-(o-fluorophenyl)-1,2-dihydrothieno[2,3-d]pyrimidin-2-one in 200 ml of dimethylformamide is added 1.76 g of 63% sodium hydride. The mixture is stirred at 60°C for 1 hour. The mixture is cooled to room temperature and 10.93 g of methyl iodide in 33 ml of dimethylformamide is added dropwise thereto. The mixture is stirred for 2 hours at room temperature. The reaction mixture is 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. From the first fraction, 2-methoxy-4-(o-fluorophenyl)-thieno[2,3-d]pyrimidine is obtained as crystals having a melting point of 175° - 176.5°C (after recrystallization from ethanol). From the second fraction, 1-methyl-4-(o-fluorophenyl)-1,2-dihydrothieno[2,3-d]pyrimidin-2-one is obtained as crystals having a melting point of 222° - 223°C (after recrystallization from ethanol). From the third fraction, 3-methyl-4-(o-fluorophenyl)-3H-thieno[2,3-d]pyrimidin-2-one is obtained as crystals having a melting point of 191° - 192.5°C (after recrystallization from ethanol).

Provenance & Evidence