4H,8H-Difurazano[3,4-b:3′,4′-e]pyrazine (DFP) is an important heat-resistant explosive intermediate, but its current synthesis process is still not scalable due to the low yields and acidic smokes in an internal chlorination step to give the intermediate DHFP. In this work, a DMA-promoted chlorination method to synthesize 5,6-dichlorofurazano[3,4-b]pyrazine is described to solve the bottleneck of DFP synthesis. The best reaction conditions were confirmed to be DMA, DHFP, and POCl₃ (2:1:40) at 120 °C for 3 h, with an increased yield of 62%. This new method not only increases the yield but also eliminates the acid smokes during postprocessing, and it is likely to find practical applications in the synthesis of DFP and other heat-resistant explosives.

中文翻译：

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5,6-二氯呋喃并[3,4-b]吡嗪的实用且可规模化合成

4 H ,8 H -二呋嗪[3,4- b :3′,4′- e ]吡嗪(DFP)是一种重要的耐热炸药中间体，但由于收率低和成本低，目前的合成工艺仍无法规模化。在内部氯化步骤中产生酸性烟雾，得到中间体 DHFP。在这项工作中，描述了一种DMA促进的氯化方法来合成5,6-二氯呋喃并[3,4- b ]吡嗪，以解决DFP合成的瓶颈。确定最佳反应条件为DMA、DHFP、POCl ₃(2:1:40)120℃反应3h，收率提高62%。这种新方法不仅提高了收率，而且消除了后处理过程中的酸烟，有望在DFP和其他耐热炸药的合成中得到实际应用。