Methanol → 2-(6-Methoxy-2-naphthyl)propionic acid

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Reaction Steps

To the benzene solution of bis(6-methoxy-2-naphthyl)zinc formed in Example 61 above is added 9.96 grams of ethyl 2-bromopropionate in 5 mL of anhydrous benzene. The temperature of the reaction mixture is maintained at from 50° to 55° C. for 15 hours, under nitrogen, and then the reaction mixture is mixed with 175 mL of 1.5N hydrochloric acid solution, followed by 65 mL of methylene chloride. The mixture is filtered, and the organic phase is separated. The aqueous acid layer is extracted with two further 30 mL quantities of methylene chloride, and the methylene chloride extracts are combined, washed with 50 mL of water, and stripped of solvents under vacuum to yield ethyl 2-(6-methoxy-2-naphthyl)propionate. A solution of 6.0 grams of potassium hydroxide, 6 mL of water and 60 mL of methanol is added to the ethyl 2-(6-methoxy-2-naphthyl)propionate, and the mixture is heated at reflux for 45 minutes, cooled to ambient temperature, acidified and mixed with 60 mL of water. Methanol is removed by evaporation in vacuo, and the resultant solution is extracted with two 60 mL portions of methylene chloride. The combined methylene chloride extracts are evaporated to dryness to yield 2-(6-methoxy-2-naphthyl)propionic acid.

Provenance & Evidence