tert-Butyl 4-(3-ethoxy-3-oxopropanoyl)piperidine-1-carboxylate → 5-Oxo-2-(4-phenoxyphenyl)-7-(piperidin-4-yl)-4,5-dihydropyrazolo[1,5-a]pyrimidine-3-carboxamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-amino-3-(4-phenoxyphenyl)-1H-pyrazole-4-carboxamide (412 mg, 1.4 mmol) and tert-butyl 4-(3-ethoxy-3-oxopropanoyl)piperidine-1-carboxylate (420 mg, 1.4 mmol) in HOAc (20 mL) was stirred at 90° C. for 16 hr. The solvent was removed under vacuum, and the residue was partitioned between aq. NaHCO3 and ethyl acetate. The organic layer was washed with brine, dried over Na2SO4 and concentrated under vacuum. The residue was purified by Pre-HPLC eluting from 25% to 90% CH3CN in 0.1% TFA in H2O. Fractions containing the desired product were combined and lyophilized overnight to afford 5-oxo-2-(4-phenoxyphenyl)-7-(piperidin-4-yl)-4,5-dihydropyrazolo[1,5-a]pyrimidine-3-carboxamide (0.3 g, 50%) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 11.71 (br s, 1H), 8.68-8.65 (m, 1H), 8.42-8.39 (m, 1H), 7.74 (d, J=8.4 Hz, 2H), 7.47-7.41 (m, 2H), 7.22-7.18 (m, 1H), 7.14-7.09 (m, 4H), 5.72 (s, 1H), 3.50-3.35 (m, 2H), 3.17-3.06 (m, 1H), 3.01-2.87 (m, 2H), 2.15-2.05 (m, 2H), 1.83-1.72 (m, 2H). MS (ESI) m/e [M+1]+ 430.1.

Provenance & Evidence