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

4H,8H-Difurazano[3,4-b:3 & PRIME;,4 & PRIME;-e]pyrazine (DFP)is an important heat-resistant explosive intermediate, but its currentsynthesis process is still not scalable due to the low yields andacidic smokes in an internal chlorination step to give the intermediateDHFP. In this work, a DMA-promoted chlorination method to synthesize5,6-dichlorofurazano[3,4-b]pyrazine is describedto solve the bottleneck of DFP synthesis. The best reaction conditionswere confirmed to be DMA, DHFP, and POCl3 (2:1:40) at 120 & DEG;C for 3 h, with an increased yield of 62%. This new method notonly increases the yield but also eliminates the acid smokes duringpostprocessing, and it is likely to find practical applications inthe synthesis of DFP and other heat-resistant explosives.