Water → 4-[4-(2,4,5-Trifluoro-phenoxy)-pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

Potassium carbonate (53 mg, 0.39 mmol) was added to a solution of 4-(4-chloro-pyrazolo[3,4-d]pyrimidin-1-yl)-piperidine-1-carboxylic acid tert-butyl ester (Intermediate 19; 100 mg, 0.3 mmol) and 2,4,5-trifluoro-phenol (available from Alfa Aesar, Ward Hill, Mass., USA; 57 mg, 0.39 mmol) in dimethylformamide (5 mL). The reaction mixture was heated at 100° C. in an oil bath overnight, then it was cooled to room temperature, and water and diethyl ether were added. The aqueous phase was extracted twice with diethyl ether and three times with hexane. The combined organic phases were evaporated and the resulting residue was purified by C18 reversed phase HPLC using a gradient of 20-100% acetonitrile/water to give 4-[4-(2,4,5-trifluoro-phenoxy)-pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid tert-butyl ester (66 mg, 50%) as a white powder. 1H NMR (300 MHz, CDCl3) δ 1.49 (s, 9H), 1.95-2.06 (m, 2H), 2.18-2.34 (m, 2H), 2.90-3.06 (m, 2H), 4.26-4.38 (m, 2H), 4.90-5.02 (m, 1H), 7.09-7.21 (m, 2H), 8.16 (s, 1H), 8.49 (s, 1H). HRMS Calcd. for C21H23F3N5O3 (MH+): 450.1748. Found: 450.1745.

Provenance & Evidence