3-Acetamido-4-methylbenzoic acid synthesis

Yield: 76%

Reaction Conditions:

Stage #1:3-amino-p-toluic acid with acetic anhydride;acetic acid at 60; for 0.75 h;
Stage #2:3-amino-p-toluic acid with 3-acetylamino-4-methyl-2-nitrobenzoic acid;acetic anhydride for 0.5 h;Heating / reflux;

Steps:

Example 12(14) Example 12Preparation of 3-(Acetylamino)-4-methylbenzoic Acid (14)
Example 12 Preparation of 3-(Acetylamino)-4-methylbenzoic Acid (14) A mixture of 3-amino-4-methylbenzoic acid (13) ((13) (27.23 g, 180.2 mmol) and acetic acid (190 ML) is heated to 60° C., and acetic anhydride (120 ML, 1300 mmol) is introduced to the reaction mixture over about 0.25 hours.The reaction mixture is then heated to reflux and stirred for about 30 minutes.The mixture is then cooled to room temperature, and the solid obtained is filtered, washed with water (100 ML), and dried to provide 3-(Acetylamino)-4-methylbenzoic Acid (14) as(14) as a light pink colored solid (26.37 g, 76% Yield).

References:

Randall, Jared Lynn;Gibbs, Richard Alan;Bosch, Gregory Kent;Curtis, Michael David;Sun, Li;Nikolaides, Nicholas US2004/167194, 2004, A1 Location in patent:Page 23