p-Toluenesulfonic acid monohydrate → HCID 68227582, compound

Participants

Reaction Conditions

Reaction Steps

7.2 g of 1-(2,3-dioxoindolin-5-yl)cyclobutanecarboxylic acid are dissolved in 100 ml of ethanol, and 500 mg of toluene-4-sulfonic acid monohydrate are added. The mixture is heated at 80° C. for 1 h and subsequently evaporated in vacuo. The residue is taken up in 100 ml of water and 100 ml of ethyl acetate, and the aqueous phase is separated off. The aqueous phase is washed a further twice with 100 ml of ethyl acetate each time. The combined organic phases are dried over sodium sulfate, filtered and evaporated to dryness in vacuo. The residue is purified by column chromatography (reversed phase), giving 2.4 g (30%) of ethyl 1-(2,3-dioxoindolin-5-yl)cyclobutanecarboxylate;

Provenance & Evidence