4,10-Dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyc lo-[5.5.0.0(5,9)0(3,11)]dodecane (TEX) was synthesized by condensation of CHOCHO with HCONH(2) to 1,4.diformyl-2,3,5,6-tetrahydroxypiperazine and its nitration with a mixt. of concd. HNO(3) and H(2)SO(4) in presence of urea at below 50 degrees C. TEX was sepd. by rapid cooling on ice and purified by crystn. from HCONMe(2), N-methylpyrrolidone, Me(2)SO, Me(2)SO-glycerol mixts. or 100% HNO(3). The crystn. from Me(2)SO-glycerol mixts. yielded product with the best crystal size needed for prodn. of TEX-based plastic-bonded explosives. The addn. of 40% TEX to a hexogen and polytetrafluoroethylene mixt. resulted in a significant decrease in sensitivity to mech. stress without any decrease of detonation velocity of the explosive.