Dimethyl Sulfate → HCID 12952274, compound

Participants

Reaction Conditions

Reaction Steps

To 100 ml of an anhydrous tetrahydrofuran solution containing 5.9 g of 7-bromo-2-hydroxy-1,2,3,4-tetrahydro-9-xanthone obtained in Example 67 was added 1.1 g of sodium hydroxide (as 55% dispersed in an oil). The mixture was stirred at 50° C. for 1 hour to which was then added dropwise 3.3 g of dimethylsulfate. The resulting mixture was agitated at 60° C. for 1.5 hours. After completion of the reaction, the solvent was removed by distillation to give a residue to which were added chloroform and water. The chloroform phase was collected and washed with water, and then dried with anhydrous sodium sulfate and purified by chromatography on silica gel. The crude crystals thus obtained were recrystallized from benzene/hexane to obtain 3.87 g (yield: 62.6%) of 7-bromo-2-methoxy-1,2,3,4-tetrahydro-9-xanthone as colorless needlelike crystals having a melting point of 139° to 142° C.

Provenance & Evidence