D
Synlett
R. Hu et al.
Letter
In summary, we have developed an effective and simple
method for the synthesis of 2-arylbenzothiazoles by using
readily available 2-aminothiophenol and aryl aldehydes as
starting materials in air/DMSO oxidant system with no cat-
alysts and no oxidants other than air. The reaction dis-
plays a broad substrate scope and good tolerance to a vari-
ety of aromatic and heteroaromatic aldehydes. Further
studies on the scope, mechanistic elucidation, and synthetic
application of this reaction are in progress in our laborato-
ry.
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Acknowledgment
We thank to the National Natural Science Foundation of China for
supporting this research (Grant No. 21072095), National High Tech-
nology Research and Development Program of China (863 Program
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tion Project in Jiangsu Province (Grant No. SJZZ15_0100).
Supporting Information
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(b) Vedernikov, A. N. Acc. Chem. Res. 2012, 45, 803. (c) Campbell,
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Supporting information for this article is available online at
http://dx.doi.org/10.1055/s-0035-1561575.
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References and Notes
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2
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2-Aminothiophenol (1a, 0.5 mmol, 1.0 equiv) and benzaldehyde
(
2a, 0.6 mmol, 1.2 equiv) were dissolved in DMSO (3 mL). Then,
the reaction mixture was stirred at 60 °C for 6 h. After the reac-
(2) Bondock, S.; Fadaly, W.; Metwally, M. A. Eur. J. Med. Chem. 2010,
tion, H O was added to the mixture. The mixture was extracted
2
45, 3692.
with EtOAc (3 × 20 mL). The combined organic layers were then
washed with sat. aq NaCl (30 mL). The solution was dried with
anhydrous Na SO , filtered, and concentrated in vacuo. The
(
(
3) Gupta, A.; Rawat, S. J. Chem. Pharm. Res. 2010, 2, 244.
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2
4
crude residue was purified with silica gel chromatography
EtOAc–PE, 1:30) to give pure compound 3a in 96% yield.
(5) (a) Sun, Y.; Jiang, H.; Wu, W. Org. Lett. 2013, 15, 1598.
(
(b) Rezazadeh, S.; Akhlaghinia, B.; Razavi, N. Aust. J. Chem. 2015,
Selected Spectral Data for 2-Phenylbenzothiazole (3a)
68, 145. (c) Luan, Y.; Zheng, N.; Qi, Y. Eur. J. Inorg. Chem. 2014,
1
H NMR (300 MHz, CDCl ): δ = 8.07–8.12 (m, 3 H), 7.91 (d, J =
3
9.0 Hz, 1 H), 7.48–7.51 (m, 4 H), 7.39 (t, J = 9.0 Hz, 1 H).
©
Georg Thieme Verlag Stuttgart · New York — Synlett 2016, 27, A–D