Synthesis of Novel Hexaazaisowurtzitane Cages to Access CL‐20

Abstract A novel hexacyclopropylhexaazaisowurtzitane (HCPIW) and hexacyclobutylhexaazaisowurtzitane (HCBIW) cage compounds were synthesized using a straightforward method by reacting glyoxal with the corresponding cycloalkylamines such as cyclopropylamine and cyclobutylamine in the presence of a catalytic amount of an acid. The obtained compounds were characterized in detail by spectroscopic and X‐ray diffraction analyses. HCPIW and HCBIW with 99% and 98% purity were obtained without column chromatography. Nitration of HCPIW with H 2 SO 4 /HNO 3 in dichloromethane solvent successfully afforded CL‐20, high energy propellant and explosive in 25% yield.