Indexed on: 17 Mar '09Published on: 17 Mar '09Published in: Catalysis Letters
In this work, the chloromethylation reaction of aromatic compounds was performed successfully by micellar catalysis in oil/water biphasic system at high reactant loadings that exceeded the solubilization capacity of micellar solutions. The effects of cationic, nonionic and anionic surfactants on the reaction were compared. The mechanism of chloromethylation reaction and the mechanism of micellar catalysis were investigated. The results show that the micellar catalysis is an effective way to realize the chloromethylation. The chloromethylation reaction consists of electrophilic substitution reaction and nucleophilic substitution reaction. Cationic surfactants, especially those containing longer hydrophobic carbon chain, are more effective. Selectivity for mono-chloromethylation was remarkably improved and regioselectivity was found to be dependent on the nature of the surfactant. Under the optimal reaction conditions, chloromethylation of isopropylbenzene could obtain 97.5% selectivity in mono-chloromethylation and 8.28 para/ortho selectivity ratio at 89.8% conversion.