ISSN 1070-4272, Russian Journal of Applied Chemistry, 2008, Vol. 81, No. 8, pp. 1479–1481. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © M.S. Salakhov, B.T. Bagmanov, V.S. Umaeva, M.I. Bagmanova, 2008, published in Zhurnal Prikladnoi Khimii, 2008, Vol. 81,
No. 8, pp. 1404–1406.
Oxidative Bromination of Aniline and Its Derivatives
M. S. Salakhov, B. T. Bagmanov, V. S. Umaeva, and M. I. Bagmanova
Institute of Polymeric Materials, National Academy of Sciences of Azerbaijan, Sumgait, Azerbaijan
Received December 12, 2007
Abstract—Oxidative bromination of aniline and its derivatives containing various substituents (CH
, Cl, NO
COOH) in ortho, meta, and para positions with a brominating mixture of NaBr (KBr) and 20–22% hydrogen
peroxide in 6–8% hydrochloric acid at the molar ratio aniline : NaBr (KBr) : H
: HCl = 1 : 3.5 : 3.2 : 4.5 is de-
Compounds containing nitrogen and bromine are
effective antipyrenes used to prepare noncombustible
polymeric materials [1, 2]. To compounds of this class
belongs 2,4,6-tribromoaniline (TBA), which also finds
use as a constituent of biologically active preparations,
pharmaceuticals , and herbicides . A variety of meth-
ods for preparing TBA have been described [4–8].
However, all these methods [2, 5] provide only a 15–50%
yield of a product that requires additional purification.
This study is concerned with the development of
a wasteless method for preparation of TBA and its de-
rivatives by oxidative bromination of aniline with a mix-
ture containing a brominating agent (potassium or so-
dium bromide) and 20–22% hydrogen peroxide in 6–8%
hydrochloric acid at 15 ± 5°C for 2 h  by the scheme:
, Cl, NO
, COOH). To determine the op-
timal conditions of oxidative bromination, we studied
how the concentrations of hydrogen peroxide and hy-
drochloric acid and the molar ratio of the reagents af-
fect the yield of tribromoaniline (TBA) for the exam-
ple of aniline and its m-substituted derivatives.
The reaction was performed in hydrochloric acid
at 15 ± 5°C in the course of 2 h.
In studying the influence exerted by the hydrogen
peroxide concentration, a 20–22% aqueous solution at
the molar ratio NaBr (KBr) : H
: HCl = 1 : 3.5 : 3.2 :
4.5 was found to be the optimal.
Under these conditions, the yield of TBA reaches
99.9%. With concentration of the H
tion raised to 25% or lowered to 16–18%, the TBA
yield decreases to 86 and 90.2%, respectively.
The yield of TBA is the highest (99.9%0) at a hy-
drochloric acid concentration of 6–8%. Lowering the
HCl concentration to 4% or raising it to 10% leads to a
decrease in the TBA yield to 86 and 90.9%, respec-
The influence exerted by the molar ratio of the re-
agents on the TBA yield in oxidative bromination of
aniline was studied at NaBr(KBr) : 20–22% H
HCl = 1 : 3 : 3 : 3, temperature of 15 ± 5°C, and reaction
time of 2 h.
It was shown that, under the above conditions,
the yield of TBA is 98%, whereas at a NaBr(KBr) : H
HCl molar ratio equal to 1 : 4.5 : 6.5 : 8.0, the TBA yield
reaches 99.9%. At the same time, to use the latter ratio
is unreasonable, because the same yield of TBA is
I–V, XI–XIV II–X, XV–XVIII
Z = Z' = X = Y = H (I), Z = Z' = X = Br, Y = H (VI); Z = Z' =
X = H, Y = CH
(II), Z = Z' = X = Br, Y = CH
(VII); Z =
Z' = X = H, Y = Cl (III), Z = Z' = X = Br, Y = Cl (VIII);
Z = Z' = X = H, Y = NO
(IV), Z = Z' = X = Br, Y = NO
(IX); Z = Z' = X = H, Y = COOH (V), Z = Z' = X = Br, Y =
COOH (X); Z = Z' = Y = H, X = NO
(XI), Z = Z' = X = Br,
X = NO
(XV); Z = Z' = Y = H, X = COOH (XII), Z = Z' =
X = Br, X = COOH (XVI); Z = Y = X = H, Z' = NO
Z = Z' = X = Br, Z' = NO
(XVII); Z = Y = X = H, Z' =
COOH (XIV), Z = Z' = X = Br, Z' = COOH (XVIII).
The reaction involved aniline and its ortho-, meta-,
and para-substituted analogues containing various sub-