Piperidine → 3-[2-(6-Morpholin-4-yl-2-oxo-1,2-dihydroindol-3-ylidenemethyl)-4,5,6,7-tetrahydro-1H-indol-3-yl]propionic acid

Participants

Reaction Steps

A mixture of 4 g of 6-(morpholin-4-yl)-2-oxindole, 3.75 g of 3-(2-formyl-4,5,6,7-tetrahydro-1H-indol-3-yl)propionic acid, and 1.8 mL of piperidine in ethanol (60 mL) was refluxed for 6 hrs. The reaction mixture was concentrated and acidified with 6 N hydrochloric acid to pH 6. The precipitate was collected by filtration, washed once with water, twice with ethyl acetate and twice with methanol to give 2.6 g of 3-[2-(6-Morpholin-4-yl-2-oxo-1,2-dihydroindol-3-ylidenemethyl)-4,5,6,7-tetrahydro-1H-indol-3-yl]propionic acid as an orange solid (34% yield).

Provenance & Evidence