1.3.5- trichloro-2,4,6-trinitrobenzene, reaction

All reported syntheses of TATB to date involve the nitration of substrates containing leaving groups which are subsequently replaced by amino groups. The current industrial synthesis of TATB (14) involves the nitration of 1,3,5-trichlorobenzene (33) to 1,3,5-trichloro-2,4,6-trinitrobenzene (34) followed by reaction with ammonia in toluene under pressure. Both nitration and amination steps require forced conditions with elevated temperatures. 

Similar routes have been used for the synthesis of other polynitrophenylenes. 1,3,5-Tris(2,4,6-trinitrophenyl)-2,4,6-trinitrobenzene (160) is synthesized from the reaction of 1,3,5-trichloro-2,4,6-trinitrobenzene with three equivalents of picryl chloride in the presence of activated copper powder in refluxing mesitylene. " 2,2",4,4, 4",6,6, 6"-Octanitro-m-terphenyl (161) has been synthesized from picryl chloride and l,3-dichloro-4,6-dinitrobenzene. ... 

Benzenetrifuroxan (66) is a powerful explosive which was first synthesised by Turek in 1931 by heating 1,3,5-triazido-2,4,6-trinitrobenzene (65) to its melting point (131 °C) the latter prepared from the reaction of 1,3,5-trichloro-2,4,6-trinitrobenzene with sodium azide in aqueous ethanol. 

The nitration of l,3,5-trichloro-2-nitrobenzene (8) to l,3,5-trichloro-2,4-dinitrobenzene (9) with dinitrogen pentoxide in absolute nitric acid goes to completion in only 2-4 minutes at 32-35 °C. Further nitration of (9) would yield l,3,5-trichloro-2,4,6-trinitrobenzene (10) which undergoes ammonolysis on treatment with ammonia in toluene to give the thermally stable explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) (11). The same sequence of reactions with l,3-dichloro-2-nitrobenzene provides a route to l,3-diamino-2,4,6-trinitrobenzene (DATE). Such reactions are clean and occur in essentially quantitative yield. 

As a starting material for the preparation of sym-trinitrotriazidobenzene, 1,3,5-trichlorobenzene is used. It is obtained by the chlorination of aniline and the removal of the amino group. Nitration to the trinitro derivative is described in Vol. I. The final reaction is simple powdered 1,3,5,-trichloro-2,4,6-trinitrobenzene is added to an aqueous alcohol solution of sodium azide. The precipitated product is washed with alcohol and water and dried at a moderate temperature. The product so obtained may be purified by crystallization from chloroform. 

Trichloro-2,4,6-trinitrobenzene is prepared by the nitration of trichlorobenzene with a mixture of nitric acid and sulfuric acid. 1,3,5-Trichloro-2,4,6-trinitrobenzene is then converted to l,3,5-trinitro-2,4,6-triaminobenzene (TATB) by nitrating with ammonia as shown in Reaction 7.4. The yellow-brown crystals of TATB are filtered and washed with water. 

Triazido-2,4,6-trinitrobenzene can be easy synthesized by the action of alkaline azide on 1,3,5-trichloro-2,4,6-trinitrobenzene. The product is slightly soluble in the reaction mixture from which it precipitates. The sodium azide can be used in the form of an aqueous ethanol solution while l,3,5-trichloro-2,4,6-trinitrobenzene in the form of an acetone solution or alone [153, 154,159, 160]. Purification of TATNB may be done by crystallization from solvents such as chloroform [153,154,159,160], acetic acid, or mixture of acetic acid and acetone 1/1 (the last mixture is recommended for preparation of single crystals for stractural studies) [155]. 

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