Methanol → 5-Cyano-1-(2,4-dimethoxybenzenesulfonyl)-3-hydroxy-3-(2-ethoxyphenyl)-indol-2-one

Participants

Reaction Steps

1.7 g (15 mmol) of potassium tert-butanolate were added in portions to 4 g (13.6 mmol) of the intermediate 1b in 40 ml of anhydrous dimethylformamide at 0° C., and the mixture was stirred for about 90 minutes. Then 3.4 g (14.3 mmol) of 2,4-dimethoxybenzenesulfonyl chloride were rapidly added dropwise at 0° C. The reaction mixture was stirred at 0° C. for 2 h. This solution was then poured into an ice-water/K2CO3 solution, resulting in a precipitate which was isolated. The resulting residue was treated with a little methanol, filtered off with suction and dried, resulting in 3.3 g of the product.

Provenance & Evidence