Synthesis of 1,3,5-trinitro-1,3,5-triazacyclohexane

#1. Field of the Invention

#This invention relates to a method of preparing pure 1,3,5-trinitro-1,3,5-triazacyclohexane by the direct liquid phase nitration of hexamethylenetetramine.

#2. Description of the Prior Art

#The method of the present invention for preparing 1,3,5trinitro-1,3,5-triazacyclohexane of high technical purity provides particular advantages over existing methods. The nitrating agent N2O5 in 100% HNO3 is stable indefinitely when kept at low temperatures near 0.degree. C. under a separate chlorinated hydrocarbon phase. Additionally, the method produces pure 1,3,5trinitro-1,3,5triazacyclohexane with no trace of 1,3,5,7-tetraaza-1,3,5,7tetranitrocyclooctane contaminent requiring removal with additional steps. Both features provide for easy and economical scale-up.

#The improved synthesis of 1,3,5-trinitro-1,3,5-triazacyclohexane proceeds via nitrolysis of hexamethylenetetramine. The nitrating agent is a solution of about 20% to about 30% by weight N2O5 in 100% HNO3. The hexamethylenetetramine is then added slowly to the nitrating solution kept at -20.degree. C. under a separate chlorinated hydrocarbon phase. The reagent are mixed for a sufficient time for the nitrolysis reaction to go to completion. After that time, the 1,3,5-trinitro-1,3,5-triazacyclohexane formed is extracted from this solution into ethyl acetate. After drying and solvent removal, the pure product is isolated under vacuum.

#The following example is given to illustrate but not limit the invention.