Meerwein reaction of benzothiazole-2-diazonium tetrafluoroborate [5]

Full text of DOI:10.1134/S1070363206110338

ISSN 1070-3632, Russian Journal of General Chemistry, 2006, Vol. 76, No. 11, pp. 1844 1845.
Pleiades Publishing, Inc., 2006.
Original Russian Text
V.M. Naidan, G.D. Naidan, 2006, published in Zhurnal Obshchei Khimii, 2006, Vol. 76, No. 11, p. 1929.
LETTERS
TO THE EDITOR
Meerwein Reaction
of Benzothiazole-2-diazonium Tetrafluoroborate
V. M. Naidan and G. D. Naidan
Bogdan Khmel’nitskii Cherkassy National University,
bulvar Shevchenko 81, Cherkassy, 18031 Ukraine
Received August 3, 2006
DOI: 10.1134/S1070363206110338
Reactions of unsaturated compounds with diazo-
nium salts derived from benzothiazol-2-amines were
not reported [1 6]. Presumably, the reason is that
benzothiazole-2-diazonium salts can be obtained only
by diazotization in the presence of a large excess of
concentrated sulfuric acid, whereas unsaturated com-
pounds undergo tarring in such diazonium salt solu-
tions. We recently proposed to use 3-(1,3-benzothia-
zol-2-yl)-1,1-dimethyltriazenes as reagents alternative
to 1,3-benzothiazole-2-diazonium salts [7, 8].
We have found that styrene reacts with 1,3-benzo-
thiazole-2-diazonium tetrafluoroborate in aqueous
acetone at 8 10 C provided that the reaction mixture
contains concentrated hydrochloric acid and copper(II)
chloride. The reaction is accompanied by liberation
of nitrogen from the diazonium group, the product is
-(1,3-benzothiazol-2-yl)-2-phenylethene (I); it is
formed by replacement of hydrogen in the methylene
group of styrene by a benzothiazolyl group.
1
N
CuCl , HCl
N
2
+
+ HBF4.
N BF
N2
2
4
S
S
I
1
The structure of compound I was proved by the H
ethanol water (2:1). Yield 0.7 g (16%), light yellow
crystalline substance, mp 105 106 C. H NMR spec-
trum, , ppm: 7.391 7.455 m (4H, m-H, p-H, 6-H),
1
1
NMR data. The H NMR spectrum of I contained a
doublet at
7.658 7.673 ppm from the ethylene
protons, which was not overlapped by the other
signals.
7
.516 7.536 t (1H, 5-H), 7.658 7.673 d (2H, CH=CH,
J = 6.0), 7.783 7.801 d (2H, o-H, J = 7.2), 7.992
.012 d (1H, 7-H, J = 7.6), 8.096 8.115 d (1H, 4-H,
J = 7.6). Found N, %: 6.27, 6.12. C H NS. Cal-
8
1
-(1,3-Benzothiazol-2-yl)-2-phenylethene (I).
A three-necked flask was charged with 4 ml of styrene,
2 ml of acetone, 6 ml of concentrated hydrochloric
1
5
11
culated N, %: 5.90.
1
acid, and 0.8 g of CuCl , and 4.7 g of 1,3-benzothia-
REFERENCES
2
zole-2-diazonium tetrafluoroborate was added in small
portions under continuous stirring, maintaining the
temperature at 8 10 C. When the addition was com-
plete, the mixture was allowed to warm up to room
temperature, stirred until nitrogen no longer evolved,
poured into 200 ml of water, and extracted with di-
ethyl ether. The solvent was evaporated at room tem-
perature, and the residue was recrystallized from
1
. Dombrovskii, A.V., Usp. Khim., 1957, vol. 26, no. 6,
p. 695.
2. Dombrovskii, A.V., Reaktsii i metody issledovaniya
organicheskikh soedinenii (Reactions and Methods of
Investigation of Organic Compounds), Moscow: Gos.
Nauch.-Tekh. Izd. Khim. Lit., 1962, vol. 11, p. 285.
3. Rondestvedt, C.S., Organic Reactions, Cope, A.C., Ed.,
1844

MEERWEIN REACTION
1845
New York: Wiley, 1960, vol. 11. Translated under the
title Organicheskie reaktsii, Moscow: Mir, 1965,
vol. 11, p. 199.
6. Grishchuk, B.D., Gorbovoi, P.M., Ganushchak, N.I.,
and Dombrovskii, A.V., Usp. Khim., 1994, vol. 63,
no. 3, p. 269.
4
5
. Rondestvedt, C.S., Jr., Organic Reactions, Dau-
ben, W.G., Ed., New York: Wiley, 1976, vol. 24,
p. 225.
. Dombrovskii, A.V., Usp. Khim., 1984, vol. 53, no. 10,
p. 1625.
7
. Naidan, V.M. and Naidan, G.D., UA Patent no. 75820;
Byul., 2006, no. 5.
8. Naidan, V.M., Naidan, G.D., and Naidan, O.V., UA
Patent no. 75834; Byul., 2006, no. 5.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 76 No. 11 2006