Hydrochloric Acid → 2-(9H-carbazole-4-yloxy)-2-methylpropionic acid

Participants

Reaction Conditions

Reaction Steps

4.35 g of potassium carbonate was added to N,N-dimethylformamide (15 mL) solution of 1 g of 4-hydroxycarbazole and 4.72 g of ethyl 2-bromo-2-methylpropionate, and stirred at 90° C. for 4 hours. The reaction mixture was allowed to cool to room temperature, ice water was added thereto thereafter, and extracted twice with ethyl acetate. The combined extract was washed with brine and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated in vacuo. The residue was purified by NH silica gel chromatography (ethyl acetate:n-hexane=1:2), and ethyl 2-(9H-carbazole-4-yloxy)-2-methylpropionate was prepared. 5 N sodium hydroxide solution was added to the prepared ethanol 30 mL solution of ethyl 2-(9H-carbazole-4-yloxy)-2-methylpropionate, and stirred at 70° C. for 1 hour. The reaction mixture was allowed to cool to room temperature, 1 N hydrochloric acid was added thereafter to be acidified, and extracted twice with ethyl acetate. The combined extract was washed with brine and dried over anhydrous sodium sulfate. After filtration, the filtrate was concentrated in vacuo. The filtrate was crystallized from diisopropylether, and isolated by filtration, washed with n-hexane, dried under reduced pressure, and 1.18 g of the subject compound was prepared as yellow crystal.

Provenance & Evidence