4-Toluenesulfonyl chloride → 2-{6-[Bis(tert-butoxycarbonyl)amino]-4-chloro-1-[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]-1H-pyrazolo[3,4-d]pyrimidin-3-yl}ethyl 4-methylbenzenesulfonate

Participants

Reaction Steps

Triethylamine (0.048 mL), p-toluenesulfonyl chloride (43 mg) and 4-dimethylaminopyridine (0.7 mg) were added to a mixture composed of di-tert-butyl{4-chloro-3-(2-hydroxyethyl)-1-[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]-1H-pyrazolo[3,4-d]pyrimidin-6-yl}imidodicarbonate of 8) above (64 mg) and dehydrated dichloromethane (1 mL) under cooling in an ice bath. The ice bath was removed and the mixture was stirred for 12 hours. The reaction mixture was diluted with ethyl acetate and sequentially washed with water and brine. The organic layer was dried over anhydrous sodium sulfate and filtered, and then the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (ethyl acetate-hexane) to obtain the title compound (74 mg, 91%) as an amorphous substance.

Provenance & Evidence