Hydrogen Bromide → 3-(3,5-Dichlorophenylamino)-4-hydroxybenzoic acid

Participants

Reaction Steps

A solution of 3-(3,5-dichlorophenylamino)-4-methoxybenzoic acid methyl ester (4.48 g, 13.74 mmol), 100 mL of concentrated HBr, and 60 mL of acetic acid was heated to reflux. After 6 days, the reaction was cooled to room temperature and concentrated aqueous ammonium hydroxide was added in portions until the pH=4. The mixture was extracted with ethyl acetate three times, and the combined extracts were washed with brine (2×) and H2O (2×) then dried over MgSO4 and stripped of solvent in vacuo. The residue was triturated with 5% ether/hexane, filtered off and dried to afford the product (3.7 g); m.p. 166-167° C.

Provenance & Evidence