p-Toluenesulfonic acid monohydrate → 7-(2-Chloro-4,6-dimethylphenyl)-2-methyl-3-(1-propyl but-1-enyl)-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridine

Participants

Reaction Conditions

Reaction Steps

4-[7-(2-Chloro-4,6-dimethylphenyl)-2-methyl-4,5,6,7-tetrahydro-2H-pyrazolo[3,4-b]pyridin-3-yl]heptan-4-ol (2-1; 594 mg) and p-toluenesulfonic acid monohydrate (74 mg) were combined in 13 mL toluene and the stirred mixture was heated to 110° C. for 11 h. The reaction mixture was then cooled to room temperature and partitioned between ethyl acetate and aqueous sodium bicarbonate. The aqueous phase was washed with additional ethyl acetate. The combined ethyl acetate fractions were washed with brine, dried with magnesium sulfate, and concentrated. The residue was chromatographed on silica gel eluting with an acetone/hexane gradient to provide 461 mg of compound 3-1 which was recrystallized from hexane: mp 86.7-88.2° C.

Provenance & Evidence