液质联用技术对芳硝基物还原制芳香羟胺反应的研究

HPLC-MS Analysis for Reduction of Aromatic Nitro Compounds to the Corresponding Hydroxylamines

采用高效液相色谱-电喷雾质谱联用技术对芳硝基化合物选择性还原制羟胺的反应液进行直接分析,并对组分的结构进行了归属。对于不同溶剂中铁氧化物催化水合肼还原邻二硝基苯为邻硝基苯基羟胺的反应,分析表明,质子溶剂有利于邻二硝基苯还原,相同实验条件下,异丙醇为溶剂的反应体系中原料邻二硝基苯转化率高;乙醚为溶剂的反应体系中产物邻硝基苯基羟胺的选择性高。对于面包酵母还原芳硝基化合物制芳香羟胺的反应,芳环上具有吸电子取代基时,有利于得到芳香羟胺,在实验所选的一系列芳硝基化合物中,对1,2-二氰基-4-硝基苯还原的羟胺选择性大于98%。

High performance liquid chromatography-mass spectrometry （HPLC- MS ） was employed to analyze aromatic nitro compounds reduction. The species of most of the ingredients in reaction solution were deduced from the information given by HPLC-MS. For the reduction of 1,2-dinitrobenzene with hydrazine hydrate in the presence of iron oxide, the conversion of 1,2-dinitrobenzene pre- ferred protic solvents, and the highest conversion of 1,2-dinitrobenzene （85%） was obtained when isopropanol was used; while, the selective preparation of N- （2-nitrophenyl） hydroxylamine preferred the solvent of ether, in which the ratio of hydroxylamine was higher. For the reduction of aromatic nitro compounds with baker＇s yeast, it was found that the electron-withdrawing group on nitro-com- pounds was favorable for the reduction of aromatic nitro-compounds to the corresponding hydroxylamines ; the reduction of 4-nitro-1,2- dicyanobenzene to 4-hydroxyamino-1,2-dicyanobenzene gained the highest ratio （〉98%） under the improved conditions.