2-Chlorobenzoic acid

Description

2-Chlorobenzoic acid is an organic compound with the formula ClC6H4CO2H. It is one of three isomeric chlorobenzoic acids, the one that is the strongest acid. This white solid is used as a precursor to a variety of drugs, food additives, and dyes.

Chemical properties

2-chlorobenzoic acid is a white to pale cream crystals or powder, It is insoluble in water, 95% ethanol solution and toluene solution, soluble in methanol, anhydrous ethanol, ether, acetone and benzene.It is the intermediate of fungicide flubenthrinol, insecticide mirex and bollenuron, and acaricide tetrabenazine.

The Uses of 2-Chlorobenzoic acid

2-Chlorobenzoic acid was used to study the degradation of 2-bromobenzoic acid by Pseudomonas aeruginosa.

The Uses of 2-Chlorobenzoic acid

The toxicity of halogenated benzoic acids was found to be directly related to the compound's hydrophobicity. Toxicity and quantitative structure-activity relationships of benzoic acids to Pseudokirchn eriella subcapitata.

The Uses of 2-Chlorobenzoic acid

Preservative for glues, paints. Intermediate in the manufacture of fungicides and dyes.

Definition

ChEBI: 2-chlorobenzoic acid is a monochlorobenzoic acid having the chloro group at the 2-position. It has a role as a plant hormone and a plant metabolite. It is a monochlorobenzoic acid and a 2-halobenzoic acid. It is a conjugate acid of a 2-chlorobenzoate.

Preparation

It is prepared by the oxidation of 2-chlorotoluene. The laboratory scale reaction employs potassium permanganate. Alternatively it arises by the hydrolysis of α,α,α-trichloro-2-toluene.
The chloride is readily replaced by ammonia to 2-aminobenzoic acid. At elevated temperature it decarboxylates.

Synthesis Reference(s)

The Journal of Organic Chemistry, 44, p. 1247, 1979 DOI: 10.1021/jo01322a012
Tetrahedron Letters, 35, p. 1539, 1994 DOI: 10.1016/S0040-4039(00)76752-9

General Description

Crystals or fine fluffy white powder.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

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

Fire Hazard

Flash point data for 2-Chlorobenzoic acid are not available; however, 2-Chlorobenzoic acid is probably combustible.

Purification Methods

Crystallise the acid successively from glacial acetic acid, aqueous EtOH, and pet ether (b 60-80o). Other solvents include hot water or toluene (ca 4mL/g). The crude material can be initially purified by dissolving 30g in 100mL of hot water containing 10g of Na2CO3, boiling with 5g of charcoal for 15minutes, then filtering and adding 31mL of 1:1 aqueous HCl. The precipitate is washed with a little water and dried at 100o. [Beilstein 9 IV 956.]