Improvement in the Synthesis of 2-Chloro-3-cyanopyridine
GE Lin-dan, DU Xiao-hua(Catalytic Hydrogenation Research Center, Zhejiang University of Technology, Hangzhou 310014, China)
2-Chloro-3-cyanopyridine was synthesized by adding dropwise an organic alkali into the mixture of 3-cyanopyridine N-oxide and bis(trichloromethyl)carbonate (BTC) in an organic solvent at -5-40 °C, and then heated to 30-75 °C for chlorination reaction. An optimized yield of 86% was obtained. It had such advantages as improved operational safety and reduced environmental pollution, by using bis(trichloromethyl)carbonate to replace phosphorous oxychloride.