PHOTODECOMPOSITION OF CHLOROBENZOIC ACIDS

Ultraviolet irradiation of 2-, 3-, and 4-chlorobenzoic acids as aqueous solutions of their sodium salts led to replacement of the chlorine by hydroxyl and hydrogen to produce the corresponding hydroxybenzoic acids and benzoic acid itself. In the case of the 4-chloro isomer, conversions to benzoic acid reached 90%. A mixture of 4-acetylbenzoic acid and terephthalic acids also was formed. In sunlight, the monochlorobenzoic acids remained unaffected, while amiben (3-amino-2,5-dichlorobenzoic acid) decomposed rapidly. © 1969, American Chemical Society. All rights reserved.