Total Mineralization of Carbon Tetrachloride under Basic Phase Transfer Conditions

Complete dechlorination of carbon tetrachloride to the mineral level was realized under mild conditions in the presence of a solid caustic base, a quaternary ammonium phase transfer catalyst and a cocatalyst such as an alcohol which functioned also as a solvent. The solvent and the catalyst could be readily recovered and recycled after completion of the process. The reaction is sufficiently fast to avoid neutralization of the formed carbon dioxide, and consequently the overall stoichiometry of the process is: CCl4 + 4NaOH → 4NaCl + CO2 + 2H2O. The key step in the reaction mechanism is the extraction of alkoxide anion by the phase transfer catalyst followed by consecutive nucleophilic substitution and hydrolysis of the substrate.