Catalytic Synthesis of Dimethyltoluene-2,4-dicarbamate by the Methoxycarbonylation of 2,4-Toluene Diamine with Dimethyl Carbonate Using Zn (OAc)_2·2H_2O

摘要

The methoxycarbonylation of 2,4-toluene diamine(TDA) and 4,4'-diphenylmethane diamine(MDA), with dimethyl carbonate to the corresponding dicarbamates using Zn compounds was carried out at 453 K. Zn(OAc)_2·2H_2O yields dimethyltoluene-2,4-dicarbamate in 92% yield in 2h, while it yields dimethyl-4,4'-methylenediphenyldicarbamate in 98 % yield at 453 K in 2 h. The structure of methyl 3-amino-4-methyl phenyl carbamate, which is one of the intermediates for the reaction of 2,4-toluene diamine with dimethyl carbonate into dimethyltoluene-2,4-dicarbamate, has been determined by measuring NOE spectrum of ~1H NMR.