1,3-Cyclohexanedione → HCID 59825774, compound

Participants

Reaction Steps

A mixture of 3-amino-2-ethoxycarbonyl-pyrrole (3.19 g, 20.7 mmol), 5-(4,6-difluoro-1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehyde (5.80 g, 20.7 mmol) and 1,3-cyclohexanedione (2.32 g, 20.7 mmol) in 80 ml of 1-butanol is heated at reflux temperature for 3 hours. The reaction mixture is then concentrated under reduced pressure and the residue is purified on a silica gel column (150 g) eluted successively with cyclohexane/ethyl acetate (9/1, v/v) and cyclohexane/ethyl acetate (7/3, v/v). The fractions containing the expected product are concentrated under reduced pressure. The residue is resuspended in 100 ml of acetonitrile and heated at reflux temperature for 30 minutes. The mixture is allowed to cool to room temperature and the insoluble material is collected by filtration. The solid is washed with acetonitrile (400 ml), diisopropyl ether (100 ml) and pentane (100 ml) and dried under vacuum to yield 3.8 g of 9-[5-(4,6-difluoro-1H-benzimidazol-2-ylsulfanyl)-furan-2-yl]-8-oxo-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylic acid ethyl ester as a white powder. Yield=36%. Analytical LC/MS method B: m/z=509 (negative ion mode [M−H]−), m/z=511 (positive ion mode [M+H]+).

Provenance & Evidence