Sodium Hydroxide → N-Butyl beta-carboline-3-carboxylate

Participants

Reaction Steps

Compound 17 (2.1 g, 10 mmol), NaOH (0.8 g, 20 mmol), n-butanol (100 ml) and thionyl chloride (5 ml) were added into a 250 ml round-bottom flask. The mixture was refluxed for 6 h. Excessive n-butanol was then removed in reduced pressure. The residues were dissolved in water followed by the addition of ethyl acetate. While being stirred, the mixture was adjusted to pH 8 with NaHCO3 solution. The organic layer was isolated. The aqueous phase was extracted with ethyl acetate. The organic phases were combined, washed with water and brine, dried over anhydrous sodium sulfate, decolorized with activated carbon and concentrated in vacuum. The residues were dissolved in ethyl acetate, and purified by silica gel column chromatography with ethyl acetate as the eluent, the recrystallized with ethyl ether/petroleum ether (2:5) to afford white needle crystals (1.8 g, 67%), and mp 211-212° C. (reference [1]: 210-211° C.).

Provenance & Evidence