Sodium hydride → methyl 4-{[7-(methylthio)-2H-pyrazolo[4,3-d]pyrimidin-2-yl]methyl}benzoate

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Reaction Steps

To a solution of 7-(methylthio)-1H-pyrazolo[4,3-d]pyrimidine (400 mg) in N,N-dimethylformamide (8 mL) was added 60% sodium hydride (98 mg) under ice-cooling, and the mixture was stirred at room temperature for 10 min. Then, ethyl 4-(bromomethyl)benzoate (606 mg) was added under ice-cooling, and the mixture was stirred at room temperature for 30 min. After the completion of the reaction, the mixture was diluted with ethyl acetate and washed with saturated aqueous sodium hydrogen carbonate and saturated brine. The organic layer was concentrated under reduced pressure, and the residue was subjected to silica gel column chromatography (hexane:ethyl acetate=2:1→1:2) to give methyl 4-{[7-(methylthio)-1H-pyrazolo[4,3-d]pyrimidin-1-yl]methyl}benzoate (251 mg) and methyl 4-{[7-(methylthio)-2H-pyrazolo[4,3-d]pyrimidin-2-yl]methyl}benzoate (450 mg) both as pale-yellow solids.

Provenance & Evidence