Water → 4-Amino-5-cyano-2-hydroxy-3-methylbenzoic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of LiOH×H2O (8.4 g, 0.2 mol) in ethanol/water (1:1, 300 mL) was added compound 74 (22 g, 0.1 mol) at RT and the reaction mixture was refluxed at 80° C. for 4 h. The reaction mixture was concentrated under vacuum, the obtained residue was diluted with water (100 mL), washed with pet. ether/ethyl acetate (1:1, 2×200 mL). The aqueous layer was separated, acidified to pH=5 using 1.5N HCl and the obtained solid product was filtered off. The aqueous layer was further extracted with ethyl acetate (2×300 mL), dried and concentrated to give more product. The combined products was washed with 5% ethyl acetate in pet. ether to give the pure title compound (19 g, >95%).

Provenance & Evidence