一锅法合成二硝基五亚甲基四胺反应机理的研究

二硝基五亚甲基四胺(DPT)是高性能单质炸药奥克托金(HMX)的重要硝化前体.以尿素为起始原料,中间产物不分离,经硝化、水解、Mannich缩合等反应得到DPT,总收率63.2%.通过分离、捕获中间体以及同位素示踪实验研究了一锅法合成DPT的反应机理.分离出了稳定的中间体二硝基脲、硝酰胺和二羟甲基硝酰胺,用苯磺酰氯捕获到了活性中间体1-硝基-六氢均三嗪.以氘代甲醛、二羟甲基硝酰胺和氨缩合得到氘标记的DPT,1HNMR和MS分析结果表明:在反应过程中二羟甲基硝酰胺解离释放出甲醛和硝酰胺,小分子碎片随机组合生成了三嗪化合物,进而生成DPT.

Reaction Mechanism of One-Pot Synthesis of Dinitro Pentamethylene Tetramine

Dinitro pentamethylene tetramine (DPT) is an important precursor of octogen (cyclotetramethylene-tetranitramine. Starting from urea without isolation of intermediates, DPT was obtained by nitration, hydrolysis and Mannich condensation, in total yield of 63.2%. The reaction mechanism of one-pot synthesis of DPT was studied by isolating and capturing intermediates, and isotope tracing experiments. The stable intermediates dinitrourea, nitramide and bis(hydroxymethyl)nitroamine were isolated, and the active intermediate 1-nitro-hexahydrotriazine was captured by benzenesulfonyl chloride. The H² labeled DPT (DPT-D) was synthesized by the reaction of CD₂O with NH₃ and bis(hydroxymethyl)nitroamine. The analysis results from ¹H NMR and MS of DPT-D indicate that in the course of the reaction bis(hydroxymethyl)nitroamine is decomposed into CH₂O and nitramide, and the small molecule species make up randomly to form triazine, then DPT.