6-Phenyl-1,3-dihydro-indol-2-one → 3-[2-(2-Oxo-6-phenyl-1,2-dihydro-indol-3-ylidenemethyl)-4,5,6,7-tetrahydro-1H-indol-3-yl]-propionic acid

Participants

Reaction Steps

A mixture of 90 mg 6-phenyl-2-oxindole, 95 mg 3-(2-formyl-4,5,6,7-tetrahydro-1H-indol-3-yl)-propionic acid and piperidine (3 drops) in ethanol (2 mL) was held in a sealed tube at 90° C. for 4 hrs. The reaction mixture was concentrated and acidified with 6 N hydrochloric acid. The precipitate was collected by filtration and washed with water and hexane to give 59 mg of 3-[2-(2-oxo-6-phenyl-1,2-dihydro-indol-3-ylidenemethyl)-4,5,6,7-tetrahydro-1H-indol-3-yl]-propionic acid as a brown solid (31% yield).

Provenance & Evidence