2-Thiophenecarboxaldehyde → 3-[(Thien-2-yl)methylene]-2-indolinone

Participants

Reaction Steps

A mixture of oxindole (16.5 g, 0.12 mole), thiophene-2-carboxaldehyde (19.1 g, 0.17 mole) and piperidine (1 ml) in 200 ml of benzene is heated at reflux temperature for 4 hours, during which time water is separated by means of a Dean-Stark trap. Solvent is removed in vacuo and the residue is crystallized twice from ethanol to give 15 g of the product: m.p. 208.5°-210°.

Provenance & Evidence