1,3-Cyclohexanedione → HCID 59825673, compound

Participants

Reaction Steps

Alternatively example 105 can be prepared by reacting 3-amino-2-ethoxycarbonyl-pyrrole (31.5 g, 204 mmol), 5-(1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehyde (50 g, 204 mmol) and 1,3-cyclohexanedione (22.95 g 204 mmol) in 2.5 l of 1-butanol at reflux temperature for 3 hours. The reaction mixture is then concentrated under reduced pressure. The residue is resuspended in 1 l of ethanol and heated to reflux temperature for 2 hours and let to cool to room temperature. The formed insoluble material is collected by filtration, washed with ethanol (0.4 l), diisopropyl ether (0.4 l), pentane (0.4 l) and dried under vacuum. The residue is resuspended in 2 l of acetonitrile, heated to reflux temperature for 2 hours and let to cool to room temperature. The insoluble material is collected by filtration, washed with acetonitrile (0.6 l), diisopropyl ether (0.6 l), pentane (0.6 l) and dried under vacuum to yield 41.5 g of 9-[5-(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 in the base form as a light gray powder. Yield=43%. Analytical LC/MS method B: retention time=3.32 min. m/z=475.06 (positive ion mode).

Provenance & Evidence