Investigation of the solubility of octahydro-1,3,5,7-tetranitro-1,3,5,7- tetrazocine and 1,3,5-triacetyl-hexahydro-s-triazine

Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (TAT) was produced by condensation of acetonitrile and trioxane as a low cost precursor for the production of 1,3,5,7-tetranitro-octahydro-1,3,5,7-tetrazocine (HMX). However, 1,3,5-triacetyl-hexahydro-s-triazine (TRAT) was also produced as a byproduct. To develop an efficient and economical method for the separation of TAT and TRAT, the solubilities of TAT and TRAT in ethyl acetate, methanol, acetonitrile and deionized water were investigated at temperatures between 298 K and 318 K. TAT was found to be relative insoluble in ethyl acetate with a maximum solubility of about 0.0295 mol/kg ethyl acetate at 318 K, which was an order of magnitude lower than that of TRAT (0.371 mol/kg ethyl acetate). TRAT was also relatively insoluble in water (0.712 mol/kg water). Accordingly, a method for the separation of TAT and TRAT based on recrystallization in ethyl acetate and precipitation by deionized water was developed. TAT was recrystallized from ethyl acetate with a purity of 97.9 %, and TRAT was recovered from the ethyl acetate filtrate by addition of water with a purity of 98.9 %.