3-Chlorobenzoic acid

3-Chlorobenzoic acid

3-Chlorobenzoic acid is an organic compound with the formula C₇H₅ClO₂. It is a chlorinated derivative of benzoic acid, featuring a chlorine atom substituted at the 3-position relative to the carboxylic acid group. This compound is one of the three isomeric chlorobenzoic acids, the others being 2-chlorobenzoic acid and 4-chlorobenzoic acid. 3-Chlorobenzoic acid is a white solid that is sparingly soluble in water but more soluble in organic solvents such as ethanol and diethyl ether.

Properties

3-Chlorobenzoic acid has a molecular weight of 156.56 g/mol and a melting point range of 141-144 °C. Its solubility in water is limited, which is characteristic of many chlorinated organic compounds due to their relatively low polarity compared to water. The presence of the chlorine atom on the benzene ring influences the acid dissociation constant (pKa) of the carboxylic acid group, making it slightly different from that of benzoic acid itself.

Synthesis

3-Chlorobenzoic acid can be synthesized through several methods. One common approach is the nucleophilic aromatic substitution of 3-chlorotoluene with potassium permanganate (KMnO₄) as the oxidizing agent. Another method involves the chlorination of benzoic acid where the chlorine is directed to the meta position due to the electron-withdrawing effect of the carboxyl group.

Applications

3-Chlorobenzoic acid is used as an intermediate in the synthesis of other organic compounds, including dyes, pharmaceuticals, and agrochemicals. Its derivative compounds are often utilized in the preparation of pesticides, herbicides, and various pharmaceuticals due to their potential biological activities.

Safety

Like many chlorinated organic compounds, 3-Chlorobenzoic acid should be handled with care. It can cause irritation to the skin, eyes, and respiratory system. Proper safety equipment such as gloves and goggles should be used when handling this chemical. Disposal of 3-Chlorobenzoic acid must comply with local environmental regulations to prevent contamination of water sources.