Uses
2-Amino-3-methylbenzoic Acid Methyl Ester is the methyl ester derivative of 2-Amino-3-methylbenzoic Acid (A612150); a metabolite of Lidocaine (L397800) with potential herbicidal activity. 2-Amino-3-methylbenzoic Acid Methyl Ester is also used as the starting material in the synthesis of N-(2-Methoxyacetate)-N-(2-carboxy-6-methylphenyl)-alanine (M260810); a metabolite of Metalaxyl (M258740) which is an agricultural fungicide.
Synthesis
The general steps for synthesizing methyl 2-amino-3-methylbenzoate from methyl 3-methyl-2-nitrobenzoate are as follows:
Step A: Preparation of methyl 2-amino-3-methylbenzoate
Methyl 3-methyl-2-nitrobenzoate (98.5 g, 505 mmol), 5% Pd/C (Degussa CE 105 XRCAV, 1.0 g) and acetonitrile (300 mL) were mixed in a 600 mL pressure vessel. The mixture was heated to 70°C and hydrogenated at 65 psi (450 kPa) under hydrogen pressure for 8 hours. Subsequently, 5% Pd/C (1.0 g) was added supplementally and hydrogenation was continued for 8.5 hours at 100 psi (690 kPa) hydrogen pressure. Upon completion of the reaction, the reaction mixture was cooled to room temperature, the hydrogen in the reactor was replaced with nitrogen, and then filtered through a Celite diatomaceous earth filter aid. The filter cake was washed with acetonitrile (3 x 25 mL). The combined filtrates were concentrated to about 160 g, and then the total weight was adjusted with acetonitrile to 200 g. The amount of the title compound in solution was measured to be 40.3 wt%, or 80.6 g, in 97.5% yield by quantitative HPLC analysis.
References
[1] Tetrahedron, 2013, vol. 69, # 32, p. 6679 - 6686
[2] Patent: WO2006/62978, 2006, A1. Location in patent: Page/Page column 23
[3] Asian Journal of Chemistry, 2014, vol. 26, # 7, p. 1921 - 1930
[4] Organic and Biomolecular Chemistry, 2014, vol. 12, # 30, p. 5629 - 5633
[5] Chemische Berichte, 1907, vol. 40, p. 4413
