1,3-Cyclohexanedione → 8-Oxo-9-[5-(5-trifluoromethyl-1H-benzimidazol-2-ylsulfanyl)-furan-2-yl]-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylic acid ethyl ester

Participants

Reaction Steps

A mixture of 3-amino-2-ethoxycarbonyl-pyrrole (0.355 g 2.31 mmol), 5-(6-trifluoromethyl-1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehyde (0.72 g, 2.31 mmol) and 1,3-cyclohexanedione (0.259 g, 2.31 mmol) in 5 ml ethanol is heated at reflux temperature for 1 hour. The formed insoluble material is filtered off, the filtrate is concentrated under reduced pressure and purified on a silica gel column (120 g) eluted with a mixture of cyclohexane and ethylacetate (7/3, v/v). The fractions containing the expected product are concentrated under reduced pressure and purified via preparative LC/MS method B on a XBridge C18 column (Waters, 30*100 mm) eluted with a 0 to 50% in 12 min. gradient of acetonitrile in 10 mM aqueous ammonium formate pH=9.0 at a 30 ml/min. flow rate to deliver 56 mg of 8-oxo-9-[5-(5-trifluoromethyl-1H-benzimidazol-2-ylsulfanyl)-furan-2-yl]-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylic acid ethyl ester. Yield=4%.

Provenance & Evidence