3-Amino-1,5-naphthalenedisulfonic acid → 3-Hydroxy-2-methylbenzoic Acid

Participants

Reaction Steps

The process according to the invention for the preparation of 3-acetoxy-2-methylbenzoyl chloride avoids these disadvantages. It comprises reacting an alkali metal salt of 3-aminonaphthalene-1,5-di-sulfonic acid with alkali metal hydroxide and water in the weight ratio 1:(1 to 1.6):(l to 1.6) at 220 to 320° C. to give the dialkali metal salt of 3-hydroxy-2-methylbenzoic acid, separating off insoluble constituents from the reaction mixture, then adjusting the reaction mixture to a pH of 11.5 to 13.5 by addition of acid and reacting it with acetic anhydride at -5 to 25° C., precipitating the 3-acetoxy-2-methylbenzoic acid by addition of acid, separating off the 3-acetoxy-2-methylbenzoic acid and reacting it with an inorganic acid chloride to give 3-acetoxy-2-methylbenzoyl chloride.

Provenance & Evidence