Synthesis and purification of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)
View Patent ↗A method to convert surplus nitroarene explosives (picric acid, ammonium picrate,) into TATB is described. The process comprises three major steps: conversion of picric acid/ammonium picrate into picramide; conversion of picramide to TATB through vicarious nucleophilic substitution (VNS) of hydrogen chemistry; and purification of TATB.
1. A method comprising:
suspending picric acid or ammonium picrate with an ammonium salt in a dipolar aprotic solvent;
heating the suspension under a pressure ranging from 20 to 80 psi to form picramide;
converting said picramide via VNS chemistry to crude TATB;
acetylating said crude TATB to form triacetyl-TATB;
treating said triacetyl-TATB with activated carbon; and
ammonolyzing said carbon-treated triacetyl-TATB to form purified TATB.
2. The method recited in claim 1 , wherein the mole equivalents of ammonium salt to picric acid ranges from 2 to 30 and the mole equivalents of ammonium salt to ammonium picrate ranges from 1 to 30.
3. The method recited in claim 1 , wherein said ammonium salt is selected from the group consisting of diammonium hydrogen phosphate, ammonium carbamate, ammonium bicarbonate and ammonium acetate.
4. The method recited in claim 1 , wherein the dipolar aprotic solvent is selected from the group consisting of sulfolane and N-methylpyrrolidinone.
5. The method recited in claim 1 , wherein said heating is to a temperature in the range of 175 to 185° C.
6. The method recited in claim 1 , wherein said acetylation is accomplished using acetic anhydride and sulfuric acid.
7. The method recited in claim 1 , wherein said ammonolyzing is accomplished by using ammonium hydroxide and heat.
8. The method recited in claim 7 , wherein said heat is at a temperature ranging from 90–130° C. for a period of time ranging from 0.5–4 hours.
9. A method comprising:
suspending picric acid or ammonium picrate with an ammonium salt in a dipolar aprotic solvent; and
heating the suspension to a temperature in the range of 175 to 185° C. under a pressure ranging from 20 to 80 psi to form picramide.
10. A method comprising:
providing crude TATB with impurities ranging from 1–15%;
acetylating said crude TATB to form triacetyl-TATB;
treating said triacetyl-TATB with activated carbon; and
ammonolyzing said carbon-treated triacetyl-TATB to form purified TATB.