The Chemistry of Powder and Explosives - Sciencemadness Dot Org

134 AROMATIC NITRO COMPOUNDS
as a raw material for the manufacture of tetranitroanihne is now
no longer important.
Preparation of Dmitrobenzene A mixture of 25 grams of concentrated
sulfunc acid {d 1 84) and 15 grams of nitric acid (d 1 52) is heated in
an open flask m the boiling water bath in the hood, and 10 grams of
nitrobenzene is added gradually dunng the course of half an hour The
mixture is cooled somew hat," and drowned m cold water The dinitro
benzene separates as a solid It is crushed with water, washed with
water, and recrystalhzed from alcohol or from mtnc acid Dinitrobenzene
crystallizes from nitric acid in beautiful needles which are practically
colorless, m p 90°
Trinitrobenzene
1,3,5-Tnnitrobenzene (sj/m-trimtrobenzene, TNB) may be
prepared only with the greatest difficulty by the nitration of
m-dmitrobenzene Hepp 3 first prepared it by this method, and
Hepp and Lobry de Bruyn 4 improved the process, treating 60
grams of m-dinitrobenzene with a mixture of 1 kilo of fuming
sulfunc acid and 500 grams of nitric acid (d 1 52) for 1 day at
100° and for 4 days at 110°. Claus and Becker 3 obtained trinitrobenzene
by the action of concentrated nitric acid on trinitrotoluene
Tnnitrobenzoic acid is formed first, and this substance
m the hot liquid loses carbon dioxide from its carboxyl group.
,'COOIH
*_, /
NO* NO2
For commercial production the Griesheim Chem. Fabrik 6 is reported
to have used a process m which 1 part of TNT is heated
at 150-200° with a mixture of 5 parts of fuming nitric acid and
10 parts of concentrated sulfunc acid In a process devised by
J. Meyer, 7 picryl chloride (2,4,6-tnnitrochlorobenzene) is reduced
by means of copper powder in hot aqueous alcohol The
reported details are 25 kilos of picryl chloride, 8 kilos of copper
3 Ber, 9, 402 (1876); Ann, 215, 345 (1882)
*Rec trav chim, 13, 149 (1894)
5 Ber, 16, 1597 (1883)
"Ger Pat 77,353, 77,559 (1893), 127,325 (1901)
T Ger Pat 234,726 (1909)