Hydrochloric Acid → Salicylic Acid

Participants

Reaction Conditions

Reaction Steps

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 bout 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).

Provenance & Evidence