Trifluoroacetic acid methylene chloride → 3-Iodo-1-(piperidin-4-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine

Participants

Reaction Steps

A mixture of trifluoroacetic acid/dichloromethane (20:80, 250 mL) was added to a solution of tert-butyl 4-(4-amino-3-iodo-1H-pyrazolo[3,4-d]pyrimidin-1-yl)-1-piperidinecarboxylate (10.72 g, 24.1 mmol) in dichloromethane (100 mL) at 0° C. 15 minutes later, the ice-bath was removed and the reaction mixture was stirred at room temperature for 5 hours. The solvents were evaporated and the residue was dissolved in dichloromethane. Hydrochloric acid (5.0N) was added and the aqueous layer was washed with dichloromethane three times. Sodium hydroxide (50%) was added to adjust the pH to about 10. The suspension was lyophilized to reduce the volume to one third of the original volume. The solid was collect by filtration to give 3-iodo-1-(4-piperidyl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine (8.109 g, 97%). 1H NMR (CDCl3) δ 1.81 (m, 2H), 1.99 (m, 2H), 2.65 (m, 2H), 3.07 (m, 2H), 4.68 (m, 1H), 8.19 (s, 1H).

Provenance & Evidence