Hydrochloric Acid → 2-Hydroxy-p-toluic acid

Temperature

85 °C

Under nitrogen, 1.86 g (10.0 mmol) of 2-chloro-4-methylbenzoic acid was combined with 10 g of H2O. 1.11 g (15 mmol) of Ca(OH)2was then added. The mixture was heated at 85° C. under stirring for 60 min, remaining under a nitrogen atmosphere. Separately, 43 mg of CuBr and 94 mg of rac-trans-N,N′-dimethylcyclohexane-1,2-diamine (Ligand F) were combined with 1 mL deionized water under nitrogen. The resulting mixture was stirred under an air atmosphere until the CuBr was dissolved to give a blue solution. This solution was added to the stirred reaction mixture via syringe at 80° C. under nitrogen and stirred for 24 h at 80° C. After cooling to 25° C., the reaction mixture was acidified with 15% HCl, producing a white precipitate. The white precipitate was filtered and washed with water. After drying, a total of 1.45 g (9.5 mmol, 95% yield) of 2-hydroxy-4-methylbenzoic acid was collected. The purity was determined by 1H NMR to be >99%.

1. dissolutionwas dissolved
2. customto give a blue solution
3. additionThis solution was added to the stirred reaction mixture via syringe at 80° C. under nitrogen
4. stirringstirred for 24 h at 80° C
5. temperatureAfter cooling to 25° C.
6. customproducing a white precipitate
7. filtrationThe white precipitate was filtered
8. washwashed with water
9. customAfter drying

ORD record

ord-fd7ded8e40d340c292b88b1d0c0fbfd5

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07538244B2