Synthesis of CL-20 by a Greener Method Using Nitroguanidine/HNO3

CL-20 is a nitramine applied in both explosives and propellants. The traditional nitrolysis of tetraacetyldibenzylhexaazaisowurtzitane (TADB), as the key precursor for the synthesis of CL-20, requires the use of N2O4/HNO3/H2SO4 (so-called mixed acid) which has its drawbacks, especially at industrial scales. Herein, the nitrolysis of TADB with a one pot method was investigated using nitroguanidine (NQ) and guanidinium nitrate (GN)/HNO3 as new system for the synthesis of CL-20. Positive features of these nitro-debenzylation/nitro-deacetylation methods include lack of mixed acids, simple work-up and less hazardous reagents. The maximum yield of reaction (72%) was obtained under optimized conditions (NQ (3.48mmol) and TADB (0.58mmol) in 98% HNO3 (5mL) at 85 degrees C and 24h).