mChlorobenzaldehyde

m-Chlorobenzaldehyde is an organic compound with the chemical formula C₇H₅ClO. It is an aromatic aldehyde characterized by a chlorine atom attached to the meta position (third carbon) of the benzene ring. This compound is a white to off-white crystalline solid with a distinct aromatic odor, often used as a precursor in organic synthesis.

The synthesis of m-chlorobenzaldehyde typically involves the chlorination of toluene followed by oxidation. One common method is the Gattermann-Koch reaction, where carbon monoxide and hydrogen chloride react with toluene in the presence of a Lewis acid catalyst, such as aluminum chloride, to introduce the formyl group. Alternatively, it can be produced through the oxidation of m-chlorotoluene using strong oxidizing agents like potassium permanganate or selenium dioxide.

m-Chlorobenzaldehyde serves as an important intermediate in the production of pharmaceuticals, agrochemicals, and specialty chemicals. Its chlorine substituent enhances reactivity, making it useful in further functionalization, such as nucleophilic aromatic substitution or condensation reactions. The compound is also employed in the synthesis of dyes, fragrances, and certain fine chemicals.

In terms of physical properties, m-chlorobenzaldehyde has a melting point of approximately 33–35°C and is soluble in organic solvents such as ethanol, ether, and chloroform. It is relatively stable under normal conditions but should be stored away from strong oxidizing agents and direct sunlight to prevent decomposition.

Due to its potential toxicity, handling m-chlorobenzaldehyde requires appropriate precautions, including the use of gloves, goggles, and proper ventilation. It should be considered hazardous if ingested, inhaled, or absorbed through the skin, and disposal should follow local environmental regulations.