采用2-氯-4-碘-5-三氟代甲基吡啶为起始原料,与正丁基锂溶液反应制备5-三氟甲基-2-氯-4-吡啶硼酸。实验研究了合成反应过程几种反应条件对合成产率的影响情况,采用HPLC,FTIR,1 H NMR等方法对产品的纯度和结构进行了分析表征。实验结果表明:当反应温度为-70℃,反应时间为2h,反应物料配比n(2-氯-4-碘-5-三氟代甲基吡啶)∶n(硼酸三丁酯)∶n(正丁基锂)为1.00∶1.20∶1.20,溶液pH值为9.0时,5-三氟甲基-2-氯-4-吡啶硼酸的收率为83.10%,纯度可达98.65%以上。
Double-armed crown ether 15,16-bis((4-nitrophenoxy)methyl)-2,3,5,6,8,9,11,12-octahydrobenzo[b][1,4,7,10,13] pentaoxacyclopentadecine F.W. 570.54 was synthesized by dibromomethyl benzo-15-crown-5 with 4-nitrophenol in the presence of anhydrous K2CO3, characterized by spectroscopic techniques and confirmed by X-ray crystal structure analysis. The title compound crystallizes in monoclinic, space group P21/c with a = 12.840(4), b = 9.425(3), c = 22.447(7), β = 98.128(7)° and Z = 4. The structure exhibits intermolecular hydrogen bonding of C-H···O type.
以3-溴吡啶作为起始原料,与正丁基锂和硼酸三丁酯反应,制备了3-吡啶硼酸。考察了反应物配比、反应温度、反应时间、水解pH值对收率的影响。采用HPLC,FTIR,1 H NMR等方法对产品的纯度和结构进行了分析表征。实验结果表明:当反应温度为-65℃、反应时间为60min、物料配比为n(C5H4NBr)∶n(n-BuLi)∶n(B(OC4H9)3)=1.00∶1.20∶1.20、水解pH值为5.0时,3-吡啶硼酸的收率为82.20%,纯度可达99.50%以上。
