Trifluoroacetic acid → 7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridin-3-ylamine

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Reaction Steps

To a 0° C. solution of 287 mg of [7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridin-3-yl]carbamic acid tert-butyl ester (Example 12) in 9 mL of dichloromethane, was added 3 mL of trifluoroacetic acid. After 15 min, the cooling bath was removed and the reaction mixture was allowed to stir and warm to room temperature over 3 h. The reaction mixture was then diluted with dichloromethane and washed with dilute aqueous sodium hydroxide. The aqueous phase was washed with additional dichloromethane, after which the combined organics were dried with magnesium sulfate and concentrated. The residue was chromatographed on silica gel eluting with a methanol/dichloromethane gradient to provide 182 mg of 7-(2-chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridin-3-ylamine (5-45): mp 234-236° C.

Provenance & Evidence