1,3-Cyclohexanedione → 3-(4-oxo-4,5,6,7-tetrahydro-1H-indol-3-yl)propanoic acid

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-aminolevulinic acid hydrochloride (2, 50.0 g, 0.298 mol), 1,3-cyclohexanedione (1, 40.2 g, 0.359 mol), and sodium acetate (48.8 g, 0.595 mol) was added with H2O (125 mL). The reaction mixture was heated at 100° C. for 16 h. The solution was cooled to room temperature and the resultant precipitate was filtered, washed with water (200 mL×2), and air-dried to give 3-carboxyethyl-4-oxo-4,5,6,7-tetrahydro-1H-indole (3, 50.5 g, 0.245 mol) as yellow solids in 82% yield.

Provenance & Evidence