Study on Synthesis of Nitrophenyl Isocyanates Using Triphosgene

Abstract

In this paper, triphosgene respectively reacting with o-nitrophenyl aniline, m-nitrophenyl aniline and p-nitrophenyl aniline to synthesize corresponding isocyanates. The effects of reactants molar ratio, reaction time and reaction temperature on the yield were investigated. As a result, using 1,2-dichloroethane as reaction solvent, the optimum molar ratio of the three kinds of nitroaniline and triphosgene were all 2.5:1, the optimum reaction time of synthesis of o-nitrophenyl isocyanate, m-nitrophenyl isocyanate and p-nitrophenyl isocyanate respectively was 6h, 5.5h and 5h; the optimum reaction temperature of synthesis of the three kinds of nitrophenyl isocyanates were all 75°C. Under the optimal conditions, the yield of o-nitrophenyl isocyanate, m-nitrophenyl isocyanate and p-nitrophenyl isocyanate could respectively be 80.3%, 83.7% and 83.5%. The products were characterized by meltingtest, ebulliometry, IR, and HPLC