Preparation of p-Chlorophenylhydrazonoacetyl chloride using triphosgene

p-chlorophenylhydrazonoacetyl chloride was prepared using p-chlorophenylhydrazono acetic acid and bis(trichloromethyl) carbonate as starting materials.Effect of catalyst,solvent,temperature and ratio of reactants on the reaction was investigated.By orthogonal experimental design,the optimum experiment conditions were obtained as follows: using methylene dichloride as solvent,the reaction temperature was-5 ℃,the molar ratio of BTC to p-chlorophenylhydrazonoacetic acid was 0.9∶1,the molar ratio of N-methylpyrrolidone to p-chlorophenylhydrazonoacetic acid was 0.6∶1,and giving the product in 87% yield.The advantages of this approach are inexpensive raw materials and simple preparation procedure.