Hydrochloric Acid → Carvedilol

Participants

Reaction Conditions

Reaction Steps

2-(2-Methoxyphenoxy)ethylamine (III) (4.89 g) was heated to about 100° C., after which 4-(oxiran-2-ylmethoxy)-9H-carbazole (II) (3.31 g) was added portionwise. After approximately 20 minutes, the reaction mixture was cooled to about 70° C., after which water (25 ml) and ethyl acetate (15 ml) were added. The pH of the two-phase mixture was then adjusted to 5 with 2 N hydrochloric acid. The solid that formed, Carvedilol hydrochloride hydrate, is filtered, washed with water (20 ml) followed with ethylacetate (15 ml). The resulting material is reslurried in ethylacetate (50 ml) and water (20 ml) containing 5% Sodium carbonate until the pH reached 7.5. The organic phase was separated and dried over sodium sulfate. The dried solution was concentrated to a turbid solution and cooled overnight to about 4° C. Precipitated carvedilol was isolated by filteration and crystallized from isopropanol.

Provenance & Evidence