2,4-Dimethoxybenzenesulfonyl chloride → HCID 67160335, compound

Participants

Reaction Conditions

Reaction Steps

3.54 g (12.03 mmol) of 3-amino-3-(2-ethoxypyridin-3-yl)-2-oxoindoline-5-carbonitrile were dissolved in 80 ml of anhydrous dimethylformamide (dried over molecular sieve). Under an atmosphere of nitrogen and with cooling using an ice-bath, 1.49 g (13.23 mmol) of potassium tert-butoxide were added a little at a time. The colour of the reaction mixture changed, and the brown solution was stirred at 0° C. for another hour to ensure that the deprotonation proceeded to completion. At low temperature, 3.16 g (13.23 mmol) 2,4-dimethoxybenzenesulphonyl chloride were added, and the mixture was stirred at 0° C. for another two hours. The course of the reaction was monitored by TLC (silica gel, dichloromethane/methanol in a ratio of 9:1). The reaction mixture was poured into ice-water and then extracted with ethyl acetate. The organic phase was washed with saturated sodium chloride solution and dried over magnesium sulphate, and the solvent was evaporated. The residue was suspended in diethyl ether and stirred until the product precipitated as a solid and could be removed by filtration. After removal of the solvent, the mother liquor was once more treated with diethyl ether (2×) until finally, after drying, 4.67 g (9.44 mmol, 79%) of the desired 3-amino-1-[(2,4-dimethoxyphenyl)sulphonyl]-3-(2-ethoxypyridin-3-yl)-2-oxoindoline-5-carbonitrile were obtained as a solid substance.

Provenance & Evidence