A Novel Synthesis Of2-Chloro-N, N-Dimethylnicotinamide As An Intermediate Of Nicosulfuron

2-Chloro-N, N-dimethylnicotinamide is an important intermediate forpharmaceutics and pesticides. Especially, a large amout of the titlecompound is needed in the manufacture of Nicosulfuron, a super-higheffective herbicide. It’s known synthetic methods could course potentialsafe and environmental visk，due to using highly toxic materials such asthionyl chloride, phosgene and phosphorus oxychloride. Here, a newsynthetic route comprising3steps was designed to synthesis the titlecompound. Using propargyl alcohol and dipropylamine as the startingmaterials,3-dipropylaminoacrolein was obtained by catalytic oxidization,followed by a Knoevenagel condensation with2-cyano-N, N-dimethyl-acetamide and an addition-cyclization with hydrochloride to give the titlecompound.2-cyano-N, N-dimethylacetamide was prepared by the reactionof methyl cyanoacetate with dimethylamine. Effects of temperature, time,ratio and solvent, were studied. The total yield was more than59%basedon the propargyl alcohol. The yield of dipropylaminopropenal was morethan90%. The synthesis route reduced toxicity and environmental pollutionby avoiding the thionyl chloride, phosgene and phosphorus oxychloride. The waste and cost could be reduced by recovering and reusingdipropylamine in the reaction cycle.In conclusion, the new synthetic route of2-Chloro-N, N-dimethyl-nicotinamide meets the queries of green chemistry. The method is valuableto be applied in industrial scale.