4-Chlorobenzoic acid

Chemical properties

white to light yellow crystal powder. Soluble in methanol, anhydrous ethanol and ether, very slightly soluble in water, toluene and 95% ethanol.

The Uses of 4-Chlorobenzoic acid

4-Chlorobenzoic acid is a benzoic acid analogue that showed antifungal activity against strains of Aspergillus flavus, Aspergillus fumigatus and Aspergillus terreus, causative agents of human aspergillosis, in in vitro bioas says. It is used as a preservative.
P-chlorobenzoic acid is the intermediate of fungicide dimethomorph, rodenticide Warfarin, Coumatetralyl and insecticide flumethrin, and also the intermediate of dye and medicine.

The Uses of 4-Chlorobenzoic acid

4-Chlorobenzoic acid can be used:
As a ligand to synthesize luminescent lanthanide complexes for bio-labeling or fiber communication applications.
To prepare organotin(IV) chlorobenzoates exhibiting anticorrosion properties.
As a ligand to synthesize di-n-butyl(4-chlorobenzoxy)(4-chlorobenzohydroxamato)tin(IV).

Definition

ChEBI: 4-chlorobenzoic acid is a monochlorobenzoic acid carrying a chloro substituent at position 4. It has a role as a bacterial xenobiotic metabolite. It derives from a benzoic acid. It is a conjugate acid of a 4-chlorobenzoate.

Preparation

4-Chlorobenzoic acid is obtained by oxidation of p-chlorotoluene: add potassium permanganate solution to the mixture of p-chlorotoluene and water in stages. The reaction is refluxed under stirring for 5-6h, then acidified with hydrochloric acid to pH 2, filtered to obtain the crude product, and recrystallized with ethanol to obtain the finished product.

Synthesis Reference(s)

Organic Syntheses, Coll. Vol. 2, p. 135, 1943
Synthetic Communications, 25, p. 3695, 1995 DOI: 10.1080/00397919508015507
Tetrahedron Letters, 22, p. 1013, 1981 DOI: 10.1016/S0040-4039(01)82853-7

General Description

Triclinic crystals or light fluffy white powder.
4-Chlorobenzoic acid is a degradation product of indomethacin. It is degraded by Acinetobacter sp. strain ST-1 and causes its dehalogenation to yield 4-hydroxybenzoic acid under both aerobic and anaerobic conditions.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

4-Chlorobenzoic acid is incompatible with strong oxidizing agents and strong bases.

Fire Hazard

Flash point data for 4-Chlorobenzoic acid are not available; however, 4-Chlorobenzoic acid is probably combustible.

Purification Methods

Purify it as for m-chlorobenzoic acid. It has also been crystallised from hot water, and from EtOH. [Beilstein 9 IV 973.]