Methanol → 1-{1-[2-(7-methoxy-2,2-dimethyl-4-oxochroman-8-yl)ethyl]piperidin-4-yl}-1H-indole-6-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

4.0 g of the above crude product of methyl 1-{1-[2-(7-methoxy-2,2-dimethyl-4-oxochroman-8-yl)ethyl]piperidin-4-yl}-1H-indole-6-carboxylate was dissolved in 40.0 mL of tetrahydrofuran and added with 16 mL of 1 N aqueous sodium hydroxide. 20 mL of methanol was added to remove the separation of layers of the reaction mixture, and the reaction mixture was stirred at 40° C. for about 20.5 hours. When the reaction mixture was cooled with an ice-water bath and the pH was adjusted to 7 with 15 mL of 1 N hydrochloric acid, crystals precipitated. 10 mL of water was further added to this slurry, and crystals were obtained by filtration and the crystals were washed with 24 mL of a mixture of 2-propanol and water (1:5). The crystals were dried in vacuo and 3.34 g of the title compound was obtained.

Provenance & Evidence