Practical and Scalable Synthesis of 5,6-Dichlorofurazano[3,4-b]pyrazine

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.