Triethylamine → HCID 178429277, compound

Participants

Reaction Steps

4-Methyl-1H-pyrazolo[3,4-b]pyridine-3,6-diol (1 g, 6.05 mmol), 4-trifluoromethyl-piperidine-1-carbonyl chloride (1.436 g, 6.6 mmol) and triethylamine (1.68 ml, 12.11 mmol) were stirred in 25 ml of pyridine at room temp for 1 h. Addition of 0.5 ml of triethylamine was followed by stirring for 2 h, concentration and addition of ethyl acetate and water. The resulting precipitate was filtered off with suction and dried. Yield: 765 mg (37%) of 4-trifluoromethylpiperidine-1-carboxylic acid 6-hydroxy-4-methyl-1H-pyrazolo[3,4-b]pyridin-3-yl ester. The organic phase was separated off, concentrated and purified by preparative HPLC (PR18, acetonitrile/water 0.1% TFA). Yield: 96 mg (5%) of 4-trifluoromethylpiperidine-1-carboxylic acid 6-hydroxy-4-methyl-1H-pyrazolo[3,4-b]pyridin-3-yl ester. M+H+: 345.13; 102 mg (3%) of 4-trifluoromethylpiperidine-1-carboxylic acid 4-methyl-3-(4-trifluoromethylpiperidine-1-carbonyloxy)-1H-pyrazolo[3,4-b]pyridin-6-yl ester, M+H+: 524.20; 106 mg (3%) of 4-trifluoromethylpiperidine-1-carboxylic acid 6-hydroxy-4-methyl-1-(4-trifluoromethylpiperidine-1-carbonyl)-1H-pyrazolo[3,4-b]pyridin-3-yl ester, M+H+: 524.52; 54 mg (1.3%) of 4-trifluoromethylpiperidine-1-carboxylic acid 4-methyl-3-(4-trifluoromethylpiperidine-1-carbonyloxy)-1-(4-trifluoromethylpiperidine-1-carbonyl)-1H-pyrazolo[3,4-b]pyridin-6-yl ester, M+H+: 703.36.

Provenance & Evidence