2-苯基-5-(甲基丙烯酰胺基取代苯基)-1,3,4-口恶二唑合成方法的改进

Improved method for synthesis of 2-phenyl-5-(methyl acrylamide-substituted phenyl)-1,3,4-oxadiazole

提出了一种纳米γ-Fe2O3催化还原硝基成氨基的新方法,通过使用γ-Fe2O3在液相中异丙醇作氢化给予体,KOH为促进剂来研究含硝基化合物的化学选择还原。就像是在麦尔外因-彭杜尔夫(MPV)还原中H-给体的活性中心一样,异丙醇吸附在催化剂γ-Fe2O3上形成了醇盐,把氢负离子转移给硝基正离子,氢氧化钾是助催化剂,帮助电子的转移。催化剂γ-Fe2O3在合成中表现出良好的活性,反应速率、产率大大提高。并进一步合成了具有荧光性能的2-苯基-5-(甲基丙烯酰胺基取代苯基)-1,3,4-口恶二唑。用红外光谱、质谱、核磁共振谱和元素分析对合成化合物进行了结构表征。用荧光光谱仪对它们的荧光性能进行了测试,最大激发波长在333nm左右,最大发射波长在445nm左右,测试结果表明目标产物具有良好的荧光性,荧光量子产率高达0.47。

A new method of γ-Fe2O3 catalyst reducting nitro compounds to amide was introduced. Over γ-Fe2O3 propan-2-ol was used as hydrogen donor and KOH as promotor in liquid phase reaction. Propan-2-ol was adsorbed on the catalyst followed by the formation of an alkoxide, which was also known to be the activated H-donor in MPV reduction. Thus the role of catalysts was to hold both the H-donor and the H-acceptor through the Lewis acid sites in close proximity so that direct hydrogen transfer can take place smoothly. The surface alkoxide species thus formed may lead to transfer the hydride ion that attacked the nitro ions,which was promoted by the presence of KOH. The catalyst used for this syntheti- cally useful transformation showed good activity. Synthesizing 2=phenyl-5-（methyl acrylamide-substituted phenyl） 1,3,4- oxadiazole compound was described. Their structures were characterized by IR, MS, 1 H-NMR specrta and elemental analy- sis. The fluorescence property were measured by fluorometry, λEX = 333nm, λEM = 445nm, the test results showed that the target compounds had good fluorescence and fluorescence quantum yield up to 0.47.