A simple and efficient procedure for diazotization-iodination of aromatic amines in aqueous pastes by the action of sodium nitrite and sodium hydrogen sulfate

Full text of DOI:10.1134/S1070428008080253

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2008, Vol. 44, No. 8, pp. 1243–1244. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © D.A. Gorlushko, V.D. Filimonov, N.I. Semenishcheva, E.A. Krasnokutskaya, A.N. Tret’yakov, Bong Seong Go, Ho Yun Hwang, Eun
Hye Cha, Ki-Whan Chi, 2008, published in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 8, pp. 1254–1255.
SHORT
COMMUNICATIONS
A Simple and Efficient Procedure for Diazotization–Iodination
of Aromatic Amines in Aqueous Pastes by the Action of Sodium
Nitrite and Sodium Hydrogen Sulfate
D. A. Gorlushkoa, V. D. Filimonova, N. I. Semenishchevaa, E. A. Krasnokutskayaa,
A. N. Tret’yakova, Bong Seong Gob, Ho Yun Hwangb, Eun Hye Chab, and Ki-Whan Chib
a T omsk Polytechnical University, pr. Lenina 30, Tomsk, 634050 Russia
e-mail: filimonov@tpu.ru
b Department of Chemistry, University of Ulsan, South Korea
Received January 23, 2008
DOI: 10.1134/S1070428008080253
One of the most widely used methods of synthesis
of aromatic iodides is based on diazotization–iodina-
tion of aromatic amines. The diazotization is generally
carried out using accessible sodium nitrite in strongly
acidic medium at reduced temperature [1–5]. Alter-
native procedures involve more expensive alkyl nitrites
as diazotizing agents in the presence of diiodomethane
or other sources of iodine [6, 7]. We previously pro-
posed simple procedures for diazotization–iodination
with sodium nitrite at room temperature in weakly
acidic media created by p-toluenesulfonic acid [8] or
sulfonated cation exchangers [9]. We recently de-
scribed successful diazotization–iodination in aqueous
pastes by grinding substituted anilines with p-toluene-
sulfonic acid [10]. In the present communication we
report on facile diazotization of a large number of sub-
stituted anilines I–XIV and 5-aminouracil (XIV) with
sodium nitrite in aqueous paste by the action of more
accessible and ecologically safe acidic reagent, sodium
hydrogen sulfate; the subsequent iodination is effected
by addition of potassium iodide.
An aromatic amine (2 mmol) was ground with solid
sodium hydrogen sulfate (6 mmol) in the presence of
0.2 ml of water in an agate mortar over a period of
several minutes. Sodium nitrite (5 mmol) was then
added, and the diazotization process was complete in
approximately 10 min on occasional grinding. The
formation of diazonium salt was confirmed by a test
with β-naphthol. When the diazotization was complete,
potassium iodide (5 mmol) was added to the paste-like
diazonium salt, and the mixture was intermittently
ground over a period of 10–20 min. The iodination
process started instantaneously; immediately after ad-
dition of potassium iodide the volume of the paste-like
mixture increased due to evolution of nitrogen. On the
whole, the diazotization–iodination process took 20–
30 min. The aqueous pastes containing aryl iodides
XVI–XXX were treated with water and a solution of
sodium sulfite, and the pure products were isolated by
recrystallization or column chromatography; the yields
were moderate to good. Compounds XVI–XXX were
(1) NaHSO4, NaNO2; (2) KI
aqueous paste, 18–20°C, 20–30 min
ArNH2
ArI
I–XV
XVI–XXX
1
I–XIV, XVI–XXIX, Ar = RC6Hx; XV, XXX, Ar = 2,4-di-
oxo-1,2,3,4-tetrahydropyrimidin-5-yl (38%); I, XVI, R =
4-O2N (68%); II, XVII, R = 2-O2N (68%); III, XVIII, R =
4-Ac (75%); IV, XIX, R = 2-Ac (76%); V, XX, R = 4-I
(52%); VI, XXI, R = 2-I (67%); VII, XXII, R = 2-HOCO
(80%); VIII, XXIII, R = 4-HOCO (84%), IX, XXIV, R =
3-HO-4-HOCO (80%); X, XXV, R = 3-NC (70%); XI,
XXVI, R = 4-NC (75%); XII, XXVII, R = 4-MeO
(61%); XIII, XXVIII, R = 4-Ph (79%); XIV, XXIX, R =
2,4-(O2N)2 (30%).
identified by comparing their melting points and H
and 13C NMR spectra with the corresponding param-
eters of authentic samples.
The reaction is general, and the procedure is ap-
plicable to most anilines having both electron-donating
and electron-withdrawing substituents, though the
diazotization of weakly basic amines XIV and XV was
incomplete, and the yield of the corresponding iodides
1243

GORLUSHKO et al.
1244
was lower. On the other hand, anilines II, IV, VI, VII,
and IX having one ortho substituent gave rise to the
corresponding iodides in high yield. As a rule, the
yields of aryl iodides XVI–XXX were comparable
with those obtained in the diazotization–iodination in
aqueous pastes with p-toluenesulfonic acid [10].
REFERENCES
1. The Chemistry of Diazonium and Diazo Groups,
Patai, S., Ed., Chichester: Wiley, 1978, p. 4.
2. Godovikova, T.I., Rakitin, O.A., and Khmel’nitskii, L.I.,
Usp. Khim., 1983, vol. 52, p. 440.
3. Söderberg, B.C.G., Coord. Chem. Rev., 2004, vol. 248,
The proposed procedure is applicable for enlarged
syntheses; for example, increase in the amount of
p-aminobenzoic acid (VIII) to 15 mmol did not result
in reduced yield of 4-iodobenzoic acid (XXIII). To
ensure successful diazotization–iodination, the above
sequence of reactant mixing is necessary. When potas-
sium iodide was added simultaneously with sodium
nitrite, complex mixtures of products were obtained,
and the yields of aryl iodides were considerably lower.
p. 1085.
4. Volkert, W.A. and Hoffman, T.J., Chem. Rev., 1999,
vol. 99, p. 2269.
5. Yu, S.-B. and Watson, A.D., Chem. Rev., 1999, vol. 99,
p. 2353.
6. Friedman, L. and Chlebowsky, J.F., J. Org. Chem.,
1968, vol. 33, p. 1636.
7. Smith, W.B. and Ho, O.C., J. Org. Chem., 1990, vol. 55,
p. 2543.
Kaupp et al. [11] described a procedure according
to which grinding of a dry diazonium nitrate with
potassium iodide leads to quantitative formation of the
corresponding aryl iodide. However, this procedure
required gaseous reagents in the diazotization step, and
long time was necessary for the iodination step. More-
over, dry diazonium salts are explosive materials,
unlike reactions with “wet” salts or performed in sol-
vents. The diazotization procedure proposed by us is
safe, for the reactions occur in aqueous pastes. Further-
more, arenediazonium sulfates are stable and nonex-
plosive [1–5, 10, 12]. Our procedure is experimentally
simple, and it largely conforms to the “green chem-
istry” principles.
8. Krasnokutskaya, E.A., Semenischeva, N.I., Filimo-
nov, V.D., and Knochel, P., Synthesis, 2007, p. 81.
9. Filimonov, V.D., Semenischeva, N.I., Krasnokut-
skaya, E.A., Tretyakov, A.N., Hwang, H.Yu., and
Chi, K.-W., Synthesis, 2008, p. 185.
10. Gorlushko, D.A., Filimonov, V.D., Krasnokut-
skaya, E.A., Semenischeva, N.I., Go, B.S.,
Hwang, H.Yu., Cha, E.H., and Chi, K.-W., Tetrahedron
Lett., 2008, vol. 49, p. 1080.
11. Kaupp, G., Herrmann, A., and Schmeyers, J., Chem.
Eur. J., 2002, vol. 8, p. 1395.
12. Saunders, K.H., The Aromatic Diazo-Compounds and
Their Technical Applications, London: Edward Arnold,
1949, 2nd ed., p. 83.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 8 2008