603-79-2

white to light yellow crystal powder

2,3-Dimethylbenzoic Acid is used as a reagent in the synthesis of pyridyl benzamides as inhibitors for the kinetoplastid Trypanosoma brucei. 2,3-Dimethylbenzoic Acid is also used as a reagent in the synthesis of 2,3-Dihydro-1H-isoindole-4-carboxylic Acid (D450070) which is a reagent used in the synthesis of aminoalkylbenzoic acid derivatives for the treatment of faintness attacks, hypokinesia, cranial disorders, neurodegenerative disorders, depression, anxiety, neuropathic pain, neuropathological disorders and sleep disorders.

ChEBI: A dimethylbenzoic acid in which the two methyl groups are located at positions 2 and 3.

1. 40 mL of dry o-xylene was rapidly added to a 250 mL PTFE-lined autoclave under argon protection. 2. 2.5 g of anhydrous aluminum trichloride (AlCl3) and 1.16 g of dry N-butylimidazole were added sequentially. Add 2.5 g of anhydrous aluminum trichloride (AlCl3) and 1.16 g of dry N-butylimidazole sequentially, and seal the reaction vessel after addition. 2. Connect a carbon dioxide cylinder to the autoclave through a pipeline, adjust the valve so that the CO2 pressure is maintained at 6 MPa, start the stirrer, and set the rotation speed at 1,000 rpm, and then begin to heat the system to 40°C, and the reaction lasts for 48 hours. 3. At the end of the reaction, 150 mL of water was added to the system and stirred for 30 min. 4. The reaction mixture was extracted three times with 50 mL of ether, and the organic phases were combined, concentrated and dried to give 2.76 g of an off-white solid, i.e., crude 2,3-dimethylbenzoic acid. 5. The above crude product was dissolved in 20 mL of a 10% (w/w) sodium hydroxide solution, and filtered to remove insoluble matter, to give a filtrate. 6. The filtrate was extracted with 1 mol/L hydrochloric acid to adjust the pH of the filtrate to 1 and let it stand at room temperature for 60 min. 7. The mixture was transferred to -10°C for further crystallization and filtered to obtain crystals. 8. The crystals were dried to obtain 2.29 g of white solid 2,3-dimethylbenzoic acid in 81.3% yield.

Crystallise the acid from EtOH. It is volatile in steam. The amide has m 156o (from H2O). [Beilstein 9 H 531, 9 III 2434, 9 IV 1797.]

[1] Patent: CN107827742, 2018, A. Location in patent: Paragraph 0059; 0060