Toluene dicarbamate(TDC)is an important precursor for preparing toluene diisocyanate(TDI). The biological enzyme catalyst for the synthesis of TDC from toluene diamine(TDA) and dimethyl carbonate(DMC) is investigated....Toluene dicarbamate(TDC)is an important precursor for preparing toluene diisocyanate(TDI). The biological enzyme catalyst for the synthesis of TDC from toluene diamine(TDA) and dimethyl carbonate(DMC) is investigated. It is found that papain exhibits the best catalgtic activity and the most suitable solvent is tetrahydrofuran. The optimal reaction conditions over papain are as follows: reaction temperature, 40 ℃; reaction time, 40 minutes; n(TDA)/n(DMC)=1/20, the enzyme concentration, 17.4mg/mL; the yield of TDC is 3.94%.展开更多
文摘Toluene dicarbamate(TDC)is an important precursor for preparing toluene diisocyanate(TDI). The biological enzyme catalyst for the synthesis of TDC from toluene diamine(TDA) and dimethyl carbonate(DMC) is investigated. It is found that papain exhibits the best catalgtic activity and the most suitable solvent is tetrahydrofuran. The optimal reaction conditions over papain are as follows: reaction temperature, 40 ℃; reaction time, 40 minutes; n(TDA)/n(DMC)=1/20, the enzyme concentration, 17.4mg/mL; the yield of TDC is 3.94%.
