Hydrochloric Acid → N-[5-Cyano-1-[(2,4-dimethoxyphenyl)sulphonyl]-3-(2-ethoxypyridin-3-yl)-2-oxo-2,3-dihydro-1H-indol-3-yl]-4-piperazin-1-ylpiperidine-1-carboxamide

Participants

Reaction Steps

55.3 mg (0.07 mmol) of tert-butyl 4-[1-({[5-cyano-1-[(2,4-dimethoxyphenyl)sulphonyl]-3-(2-ethoxypyridin-3-yl)-2-oxo-2,3-dihydro-1H-indol-3-yl]amino}carbonyl)piperidin-4-yl]piperazine-1-carboxylate were initially charged in 4 ml of methanol, and 1.0 ml of 5-6 M hydrochloric acid in isopropanol was added. The mixture was stirred at room temperature. The progress of the reaction was monitored by TLC (silica gel, CH2Cl2/MeOH 9:1). After complete conversion, the alcoholic solvent residues were removed, and the residue was taken up in dichloromethane and, using 1 N aqueous sodium hydroxide solution, adjusted by extraction to pH 9. The organic phase was separated from the aqueous phase, and the aqueous phase was reextracted with dichloromethane (2×). The combined organic phase was dried over magnesium sulphate, and the solvent was removed under reduced pressure. The residue was crystallized from diethyl ether. Alternatively, the residue can also be purified either by conventional column chromatography on a normal phase (NP-SiO2 cartridge, Chromabond) using dichloromethane/methanol as mobile phases or by preparative HPLC (RP, mobile phases acetonitrile/water, 0.01% TFA). After crystallization, 15.9 mg (0.023 mmol, 33%) of N-[5-cyano-1-[(2,4-dimethoxyphenyl)sulphonyl]-3-(2-ethoxypyridin-3-yl)-2-oxo-2,3-dihydro-1H-indol-3-yl]-4-piperazin-1-ylpiperidine-1-carboxamide were isolated.

Provenance & Evidence