6-(Acetyloxy)-2-naphthalenecarboxylic acid → 6-Hydroxy-2-naphthoic acid

Participants

Reaction Steps

100 parts of a moist 6-acetoxy-2-naphthoic acid containing 60 parts of water, such as obtainable, for example, according to the above Example 6 before this product has been dried, are stirred in 300 parts of an about 70% aqueous sulfuric acid solution at a temperature between 90° and 100° C. for 4 hours. The 6-hydroxy-2-naphthoic acid which is formed and which precipitates, is filtered off after the reaction batch has been cooled to 70° to 80° C., washed with hot water and dried. 31 parts of a pure 6-hydroxy-2-naphthoic acid is obtained, having a melting point of 245° C. (according to Example 1 of U.S. Pat. No. 1,593,816, recrystallized 6-hydroxy-2-naphthoic acid has a melting point of 245° C.).

Provenance & Evidence