Synthesis of 4-Chloro-2-fluorophenyl Hydrazine with Phase Transfer Catalysis

4-Chloro-2-fluorophenyl hydrazine was synthesized using 4-chloro-2-fluoroaniline as raw material by the reaction of diazotization,reduction,acid and alkaline hydrolysis.PEG-400 was used as phase transfer catalyst(PTC) in the process of diazotization while CH3COOH was chosen as cosolvent.The total yield of 4-chloro-2-fluorophenyl hydrazine was 74%.The influence of the amount of catalyst,reaction temperature of reduction and hydrolysis on yield of 4-chloro-2-fluorophenyl hydrazine was investigated.The corresponding reaction temperatures of diazotization,reduction and hydrolysis were chosen to be 0 ℃,75 ℃ and 85 ℃.The optimized conditions were as follows: n(4-chloro-2-fluoroaniline)∶n(NaNO2)∶n(HCl)∶n(NaHSO3)= 1∶1.05∶3∶2.20(molar ratio),m(4-chloro-2-fluoroaniline)∶m(PEG-400)=1∶0.03(mass ratio).