tert-Butyl N-(2-bromoethyl)carbamate → Ethyl 6-cyclopropyl-1-[2-({[(1,1-dimethylethyl)oxy]carbonyl}amino)ethyl]-1H-pyrazolo[3,4-b]pyridine-4-carboxylate

Participants

Reaction Steps

Ethyl 6-cyclopropyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylate (125 mg, 0.541 mmol) was dissolved in DMF(10 mL), followed by addition of potassium tert-butoxide (79 mg, 0.703 mmol). After stirring for 15 minutes, 1,1-dimethylethyl (2-bromoethyl)carbamate (121 mg, 0.541 mmol) was added and the mixture was stirred at room temperature for 16 h. The reaction mixture was concentrated to dryness. The crude residue was diluted with water (50 mL) and acidified with acetic acid. The contents were extracted with DCM (4×50 mL). The combined organic layers were washed with water, brine, dried over MgSO4, filtered, and concentrated in vacuo. The crude residue was purified via silica gel chromatography (eluent: 0 to 50% EtOAc:Hex). The final product was obtained as 0.114 g (56%). LCMS E-S (M+H)=375.1. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.04-1.14 (m, 4 H), 1.15-1.20 (m, 2 H), 1.27 (s, 7 H), 1.41 (t, J=7.07 Hz, 3 H), 2.36-2.45 (m, 1 H), 3.31-3.41 (m, 3 H), 4.36-4.50 (m, 5 H), 6.84 (t, J=5.81 Hz, 1 H), 7.65 (s, 1 H), 8.24 (s, 3 H).

Provenance & Evidence