相转移催化条件下的4-氯-2-氟苯肼的合成

以4-氯-2-氟苯胺为原料,冰乙酸为助溶剂,PEG-400相转移催化作用下进行重氮化反应,再经过还原、酸析、碱解等三步反应制备出目标化合物,产率≥74.0%.考察了催化剂用量、还原温度、酸析温度对反应收率的影响,适宜的反应条件是:重氮化、还原、酸析的反应温度分别为0℃、75℃、85℃.物质量的比为n(4-氯-2-氟苯胺...

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).