What Is Methyl Chloride?
Methyl chloride encompasses a group of compounds derived from methane (CH4) through the substitution of hydrogen atoms with chlorine atoms, including chloromethane, dichloromethane, chloroform, and carbon tetrachloride. Noted for its strong, sweet aroma, methyl chloride is a notable halocarbon and an organic compound.
Uses of Methyl Chloride
Originally used as a refrigerant and solvent, the carcinogenic and ozone-depleting nature of methyl chloride has limited its industrial applications. However, it remains relevant in research and development for its solubility and stability properties.
Properties of Methyl Chloride Derivatives
- Chloromethane (CH3Cl): A gas at room temperature, flammable, with a boiling point of -24.2°C.
- Dichloromethane (CH2Cl2): A colorless liquid used in laboratories, boiling at 40°C.
- Chloroform (CHCl3): A colorless liquid with anesthetic properties, boiling at 61°C.
- Carbon Tetrachloride (CCl4): A liquid used historically in NMR spectroscopy, boiling at 76.8°C.
Synthesis of Methyl Chloride Derivatives
Methods include treating benzyl alcohol with hydrochloric acid for chloromethane, photochemical reactions of toluene and chlorine for benzyl chloride, and chlorination of aromatic compounds with zinc chloride for benzyl chloride derivatives.
Reactions Involving Methyl Chloride Derivatives
Oxidation of benzyl chloride produces benzoic acid, while its reaction with sodium cyanide yields benzyl cyanide. Benzyl chloride can also be used to synthesize quaternary ammonium salts, and benzyl ethers, and protect hydroxy groups.
Regulatory Information and Health Effects
While chloromethane poses minimal carcinogenic risk, dichloromethane, chloroform, and carbon tetrachloride have been classified under GHS for their potential carcinogenicity. These substances require careful handling due to their health risks and potential to cause bile duct cancer among exposed workers.
Environmental Impact
Carbon tetrachloride, in particular, is regulated under the Montreal Protocol as an ozone-depleting substance, with its atmospheric breakdown contributing significantly to ozone layer depletion.