Trifluoroacetic acid → 5-(3,5-Dimethylisoxazol-4-yl)-3-phenyl-3-(piperazin-1-yl)indolin-2-one

Participants

Reaction Steps

To a solution of tert-butyl 4-(5-(3,5-dimethylisoxazol-4-yl)-2-oxo-3-phenylindolin-3-yl)piperazine-1-carboxylate (0.9 g, 1.8 mmol) in CH2Cl2 (5 mL) was added TFA (5 mL) at 0° C., after adding up, the reaction was stirred at room temperature for 2.0 h. The solvent was evaporated in vacuo to give crude product. It was dissolved in water (20 mL), and was neutralized with NaHCO3 to PH=7˜8, and then the mixture was extracted with EtOAc (2×30 mL), combined organic phase, dried with Na2SO4, filtrated, concentrated to give crude product, and the mixture was purified by chromatography (eluent. CH2Cl2/MeOH/NH3H2O=20/1/0.05) to give product (500 mg, 71.6%) as a white solid. 1H NMR (400 MHz, DMSO-d6): δH 10.75 (s, 1H), 7.49 (d, J=8.0 Hz, 2H), 7.23-7.36 (m, 5H), 6.97 (d, J=8.0 Hz, 1H), 2.65-2.66 (m, 4H), 2.31-2.47 (m, 7H), 2.19 (s, 3H). MS (ESI) m/e [M+1]+ 389.

Provenance & Evidence