Analysis of polar precursors of 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) using hydrophilic interaction chromatography

Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) is currently one of the most widely used explosives. 1,3,5,7-Tetraacetyl-1,3,5,7-tetraazacyclooctane (TAT) is an attractive precursor for the synthesis of HMX; the nitration of this key precursor results in both high yield and purity under mild condition. TAT can be prepared either by acetylation of 2,6-diacetyl-pentamethylenetetramine (DAPT) or by the condensation of ACN and 1,3,5-trioxane. However, TAT and DAPT are polar compounds, and are difficult to analyze using reverse phase liquid chromatography. Herein, a chromatography method for the direct separation of these polar compounds was developed using hydrophilic interaction chromatography (HILIC) using a Venusil HILIC column, with ACN/water (95/5, v/v) as the mobile phase. The chromatographic analysis and identification of these polar compounds provide valuable information for the optimization of the synthetic process of TAT.