Trifluoroacetic acid → 4-[4-(2-Methyl-6-[1,2,4]triazol-1-yl-pyridin-3-yloxy)-pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid isopropyl ester

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Reaction Steps

A mixture of 4-[4-(2-methyl-6-[1,2,4]triazol-1-yl-pyridin-3-yloxy)-pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid tert-butyl ester (Example 101; 50 mg, 0.105 mmol), trifluoroacetic acid (428 μL) and dichloromethane (2 mL) was stirred at room temperature for 30 min. The volatiles were evaporated under high vacuum and the residue was dissolved in dichloromethane (3 mL). Isopropyl chloroformate (1 M in toluene; 158 μL, 0.16 mmol) and triethylamine (95 μL, 0.68 mmol) were added and the mixture was stirred overnight at room temperature. 1 M aqueous sodium carbonate (6 mL) and dichloromethane (3 mL) were added, and the aqueous layer was extracted twice with dichloromethane. The combined organic extracts were evaporated and the residue was purified by preparative C18 HPLC, eluting with 10-100% acetonitrile/water. Samples containing the product were extracted three times with dichloromethane and the solvent was evaporated to give 4-[4-(2-methyl-6-[1,2,4]triazol-1-yl-pyridin-3-yloxy)-pyrazolo[3,4-d]pyrimidin-1-yl]-piperidine-1-carboxylic acid isopropyl ester (35 mg, 72%) as a white powder. 1H NMR (300 MHz, CDCl3) δ 1.28 (d, 6H, J=6.0 Hz), 1.97-2.10 (m, 2H, J=10.9 Hz), 2.20-2.35 (m, 2H), 2.46 (s, 3H), 2.89-3.14 (m, 2H), 4.32-4.48 (m, 2H), 4.84-5.08 (m, 2H), 7.68 (d, 1H, J=8.8 Hz), 7.86 (d, 1H, J=8.8 Hz), 8.11 (s, 1H), 8.17 (s, 1H), 8.48 (s, 1H), 9.19 (s, 1H). Mass spectrum (ES) MH+=464. HRMS Calcd. for C22H26N9O3 (MH+): 464.2153. Found: 464.2151.

Provenance & Evidence