1-环己氧基-4-氧-2,2,6,6-四甲基哌啶酮的合成与表征

Synthesis and Characterization of 1-Cyclohexyloxy-2,2,6,6-tetramethylpiperid-4-one

受阻胺型含氮六元环烷氧胺是制备可用于聚丙烯纤维阻燃的优异阻燃剂的关键中间体。以2,2,6,6-四甲基哌啶酮(TMP)为原料,过氧化氢为氧化剂,氢氧化镁或负载Mg(Ⅱ)的离子交换树脂为催化剂,合成了2,2,6,6-四甲基哌啶氮氧自由基;以环己烷和2,2,6,6-四甲基哌啶氮氧自由基为原料,过氧化氢和七水合硫酸亚铁为氧化-还原引发体系,四丁基溴化铵为相转移催化剂合成了1-环己氧基-4-氧-2,2,6,6-四甲基哌啶酮。实验研究了合成工艺、催化剂和相转移剂对产率的影响。用电子自旋共振谱仪(ESR)、ESI-MS、1H-NMR、13C-NMR和高效液相色谱(HPLC)对产物的结构和纯度进行了表征和测定。研究结果表明,在氮氧自由基的合成中,用负载型Mg(Ⅱ)催化剂有利于产物的分离。用环己烷代替环己基甲醛作原料具有明显的成本优势。

Sterically hindered alkoxyamine of hexa-atonic cycle compound containing nitrogen is the key intermediate for synthesizing the flame retardant with excellent fire retardancy for the polypropylene fiber. Sterically hindered nitroxyl radical—1-oxyl-2,2,6,6-tetramethylpiperid-4-one was synthesized by using 2,2,6,6-tetramethylpiperid-4-one as the raw material, ion exchange resin loaded Mg（Ⅱ） as catalyst, and hydrogen peroxide as oxidant. 1-cyclohexyloxy-2,2,6,6- tetramethylpiperid-4-one was synthesized by using cyclohexane and sterically hindered nitroxyl radical synthesized above as raw materials, hydrogen peroxide and ferrous sulfate heptahydrate as oxidation-reduction initiator, and tetrabutyl ammonium bromide as phase transfer catalyst. The effects of catalyst, phase transfer catalyst and technology conditions on the syntheses were investigated. The structure and purity of products were characterized and measured by electron-spin resonance （ESR）, ESI-MS、1H-NMR、13C-NMR and HPLC. The results show that using the ion exchange resin loaded Mg（Ⅱ） as catalyst is advantageous to the separation of the sterically hindered nitroxyl radical from the reaction system, and that in the synthesis of the sterically hindered alkoxyamine, the use of cyclohexane as a raw material has the superiority of the synthesis cost.