3-氟-4-硝基苯酚的合成

Synthesis of 3-Fluoro-4-nitrophenol

研究了含氟中间体3-氟-4-硝基苯酚(FNP)的合成,由间氟苯胺经重氮化、水解、硝化及异构体分离制得。间氟苯胺重氮盐在CuSO4和硫酸介质中,用反应蒸馏技术,水解制得间氟苯酚,收率85%,质量分数95%;间氟苯酚硝化后采用水蒸气蒸馏法,把副产物3-氟-6-硝基苯酚有效除去,再经乙醚萃取、饱和NaCl水溶液洗涤、饱和NaHCO3水溶液洗涤、Na2CO3水溶液中和成盐、酸化、乙醚萃取等后处理,得到质量分数99.6%的FNP,收率23%。

3-Fluoro-4-nitrophenol （FNP）, an important fluoric intermediate, was synthesized from m- fluoroaniline by a four-step way including diazotization, hydrolysis, nitration and separation of the isomers. The diazonium salt of m-fluoroaniline was hydrolyzed by the technology of reaction distillation in the solution of CuSO4 and H2SO4 to give m-fluorophenol in 85% yield and of 95% purity. After nitration of m-fluorophenol, steam distillation was used to remove the by-product 3-fluoro-6-nitrophenol, then the residual bottom liquid was extracted with Et2O. The Et2O layer was washed with saturated aqueous NaCI and NaHCO3, and poured to a solution of Na2CO3. The precipitated sodium salt of FNP was dissolved in water, acidified, extracted by Et2O and evaporated to give FNP in 23% yield and of 99.6% purity.