Hydrochloric Acid → Salicylic Acid

Temperature

25 °C

Under nitrogen, 7.82 g (50 mmol) of 2-chlorobenzoic acid was combined with 31 g of H2O. 6.62 g (62.5 mmol) of Na2CO3 was then added. The mixture was heated to reflux with stirring for 30 min, remaining under a nitrogen atmosphere. Separately, 36 mg of CuBr and 79 mg of rac-trans-N,N′-dimethylcyclohexane-1,2-diamine (Ligand F) were combined with 1 mL H2O under nitrogen. The resulting mixture was stirred under an air atmosphere until the CuBr was dissolved to give a deep purple solution. This solution was added to the stirred reaction mixture via syringe at 80° C. under nitrogen and stirred for about 3 h at 100° C. and the reaction was monitored by 1H NMR. Table 3 shows the distribution of starting material and product at different reaction times. A product selectivity of more than 99% was observed. After reaction completion, the mixture was allowed to cool to 25° C. and the reaction mixture was acidified with 15% HCl, producing a white precipitate. The white precipitate was filtered, washed with water and dried yielding 6.00 g 2-hydroxybenzoic acid (85% yield). The filtrate was extracted with ethyl acetate and evaporated to dryness to receive another 0.65 g of 2-hydroxybenzoic acid resulting in a total yield of 6.65 g (48.2 mmol, 96% yield).

1. temperatureThe mixture was heated
2. temperatureto reflux
3. dissolutionwas dissolved
4. customto give a deep purple solution
5. additionThis solution was added to the stirred reaction mixture via syringe at 80° C. under nitrogen
6. stirringstirred for about 3 h at 100° C.
7. customat different reaction times
8. customAfter reaction completion
9. customproducing a white precipitate
10. filtrationThe white precipitate was filtered
11. washwashed with water
12. customdried

ORD record

ord-d87804f520f6494c982d25f0f974d54d

Source dataset

uspto-grants-2008_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07335791B1