Trifluoroacetic acid → (S)-3-(3-(4-(1H-imidazol-2-yl)phenyl)pyrazolo[1,5-a]pyrimidin-5-yl)-4-isopropyloxazolidin-2-one

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Reaction Steps

A solution of (S)-1-(2-(tert-butyldimethylsilyloxy)ethyl)-4-isopropyl-3-(3-(4-(1-((2-(trimethylsilyl)ethoxy)methyl)-1H-imidazol-2-yl)phenyl)pyrazolo[1,5-a]pyrimidin-5-yl)imidazolidin-2-one (15 mg, 0.022 mmol) in dichloromethane (0.3 mL) and trifluoroacetic acid (0.3 mL) was stirred at ambient temperature for 24 hours. The solvents were evaporated, and the residue was taken up in MeOH. A few drops of 1N LiOH solution was added. The mixture was stirred for 10 minutes. The reaction mixture was diluted with water and extracted with dichloromethane. The combined organic layers were washed with brine, dried and concentrated. The residue was purified by column chromatography (12% MeOH in dichloromethane) to give (S)-3-(3-(4-(1H-imidazol-2-yl)phenyl)pyrazolo[1,5-a]pyrimidin-5-yl)-4-isopropyloxazolidin-2-one (5 mg, 52%) as a pale yellow solid. 1H NMR (400 MHz, CD3OD) δ 8.66 (d, J=7.6 Hz, 1H), 8.47 (s, 1H), 8.18 (d, J=8.4 Hz, 2H), 8.13 (d, J=8.0 Hz, 1H), 7.90 (d, J=8.4 Hz, 2H), 7.16 (s, 2H), 3.2-3.8 (m, 7H), 2.91 (m, 1H), 1.12 (d, 3H), 0.89 (d, 3H). LCMS (APCI+) m/z 432.3 [M+H]

Provenance & Evidence