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聚乙二醇可作为卤素交换氟化反应有效的相转移催化剂。运用PEG - 60 0 0作相转移催化剂从对硝基氯苯合成对硝基氟苯 ,微波加热的反应速率是常规加热的近 3倍 ,对硝基氟苯的收率为 91 6 %。同样 ,在微波加热下邻硝基氯苯、2 ,5 二氯硝基苯和 3 ,4 二氯硝基苯的卤素交换氟化反应速率分别提高到常规加热的 6倍、2 4倍和 52倍 ,产物邻硝基氟苯、5 氯 2 氟硝基苯和 3 氯 4 氟硝基苯的收率分别提高到 79 2 %、66 7%和 82 8%。不同相对分子质量聚乙二醇运用于对氯硝基苯的实验发现 ,尽管可得到相近的原料转化率 ,但目标产物的收率却相差非常大 ,相对分子质量越小 ,产品收率越低
Polyethylene glycol can be used as an effective phase transfer catalyst for halogen exchange fluorination. Using PEG - 60 0 as phase transfer catalyst, p - nitrofluorobenzene was synthesized from p - nitrochlorobenzene. The reaction rate of microwave heating was nearly 3 times that of conventional heating, and the yield of p - nitrofluorobenzene was 91.6%. Similarly, the halogen exchange fluorination reaction rates of o-nitrochlorobenzene, 2, 5-dichloronitrobenzene and 3,4-dichloronitrobenzene increased 6 times, 2 4 times and 52 times respectively The yields of o-nitrofluorobenzene, o-chloronitrobenzene and o-chloronitrobenzene were increased to 79 2%, 66 7% and 82 8%, respectively. Different relative molecular mass of polyethylene glycol used in p-chloronitrobenzene experiment found that despite similar raw material conversion rate, but the yield of the target product is very different, the smaller the relative molecular mass, the lower the yield of the product