氟代脱硝合成芳香族氟化物

Synthesis of Fluoroaromatics by Fluorodenitration

对以间二硝基苯为反应底物,喷雾干燥的氟化钾(简写为SD-KF)为氟化剂,一步合成间硝基氟苯的氟代脱硝反应,考察了催化剂、反应时间、溶剂等因素对反应的影响。GC分析结果表明,在间二硝基苯用量为6.72 g(40 mmol)、SD-KF用量为9.28 g(160 mmol)、四苯基溴化钅粦用量为1.68 g(4 mmol)时,以5.8 mL(40 mmol)邻苯二甲酰氯(PDC)为NO2-捕捉剂,以二甲亚砜(DMSO)为反应介质,回流温度下反应6 h,反应的转化率和选择性可达93.2%、84.3%,间硝基氟苯收率可达78.6%。反应也可在微波辐射下进行,此时反应的转化率、选择性及产物的收率分别为97.9%、85.5%、83.7%。

Phase transfer catalysis for the fluorodenitration of m-dinitrobenzene with spray-dried KF（ SD -KF） in the presence of phthaloyl chloride （PDC） was reported. The optimum reaction conditions are：6. 72 g（40 mmol） m-dinitrobenzene,9. 28 g（ 160 mmol） SD -KF,1.68 g（4 mmol） Ph4PBr,5.8 mL （40 mmol） PDC as trapping agent of NO2^-, reflux temperature, reaction time 6 h and dimethylsulfoxide （DMSO） as solvent. Under these conditions, 78.6% m-nitrofluorobezene was obtained with 93.2% conversion and 84.3% selectivity. The fluorodenitration reaction can also be carried out under microwave irradiation with 97.9% conversion ,85.5% selectivity and 83.7% yield.