The chemistry of 2,4,6-trinitrotoluene 175under basic conditions and can attack an iminium cation formed from the reaction of formalde-
hyde with an amine. The Mannich product from one such reaction, the tertiary amine (136)
has been used for the synthesis of 2,4,6-trinitrostyrene (137).^284 In this reaction, treatment
of the tertiary amine (136) with methyl iodide leads to a quaternary ammonium salt, which
on treatment with silver (I) oxide leads to Hoffman elimination and the formation of (137).
Urba ̃nski and Bonecki^285 have reported the synthesis of 2,4,6-trinitrostyrene (137) using a
very similar strategy; the base-catalyzed condensation of TNT (1) with formaldehyde^286 gen-
erates 2,4,6-trinitrophenethyl alcohol (138), which on reaction with phosphorous oxychloride,
followed by diethylamine, yields the 2,4,6-trinitrostyrene precursor (136).
CH 3
O 2 N NO 2
O 2 NO 2 N
O 2 NNO 2
1NO 2NO 2
141CH N NMe 2NO 2NO 2
140CH CHCHO
NO 2NO 2
142NH 2NMe 2
143NaOHNaOH+PhCHO, EtOHp-NOC 6 H 4 NMe 2 ,
NaOHFigure 4.62The methyl group of TNT will condense with aldehydes in a similar way to other substrates
containing acidic protons. TNT (1) reacts exothermically with benzaldehyde in alkaline so-
lution to form 2,4,6-trinitrostilbene (140).^287 2,4,6-Trinitrobenzaldehyde (142) is synthesized
from the base hydrolysis of the imine (141) formed from the condensation of TNT (1) with
p-nitroso-N,N-dimethylaniline.^287
CH 3
O 2 N NO 2NO 2
1COOHNO 2
144O 2 N NO 2NO 2O 2 N NO 2
2H 2 SO 4 ,
Na 2 Cr 2 O 757–69 %H 2 O, heat43–46 % from 1Figure 4.63A synthetically important route to 1,3,5-trinitrobenzene on both laboratory and industrial
scales utilizes TNT as a starting material. Thus, when TNT (1) is treated with an oxidizing
mixture of sulfuric acid and sodium dichromate the product formed is 1,3,5-trinitrobenzoic
acid (144), which is thermally unstable and loses carbon dioxide on heating as a suspension
in boiling water to form 1,3,5-trinitrobenzene (2).^130