Selective synthesis of N,N-dimethyl aniline derivatives using dimethyl carbonate as a methylating agent and onium salt as a catalyst

Onium salts in the presence of a small amount of water are excellent catalysts for selective N,N-dialkylation. Side products such as carbamates formed during this reaction are hydrolyzed to N-alkylated anilines thereby increasing the selectivity for alkylated products. Reaction network has been proposed which explains the chemistry of N-alkylation by DMC. The reusability of catalyst has been demonstrated.