HCID 70665120, compound → HCID 67202892, compound

Participants

Reaction Steps

15.1 g (50 mmol) of methyl 2-pyrido[4,3-b]indol-5-ylbenzoate are suspended in a mixture of 200 ml of glacial acetic acid and 5 ml of concentrated sulfuric acid. The suspension is heated under reflux for 5 h, the acetic acid is then removed in vacuo, and the residue is taken up in 500 ml of dichloromethane and neutralised using 1 N sodium hydroxide solution. The organic phase is separated off, dried over magnesium sulfate and evaporated in vacuo. The residue is taken up in 30 ml of ethyl acetate, and 100 ml of ethanol are slowly added at elevated temperature. After cooling, the precipitated solid is filtered off with suction, washed three times with 50 ml of ethanol and dried in vacuo (p=0.1 mbar, T=60° C.). Yield: 10.5 g (39 mmol), 78%; purity: 97% (1H-NMR).

Provenance & Evidence