Arylamination of 1,2,5-thiadiazol-3-yl trifluoromethanesulfonate [7]

Full text of DOI:10.1007/s10593-005-0229-x

Chemistry of Heterocyclic Compounds, Vol. 41, No. 6, 2005
ARYLAMINATION OF 1,2,5-THIADIAZOL-3-YL
TRIFLUOROMETHANESULFONATE
Yu. M. Pustovit and A. N. Alekseenko
Keywords:
N-aryl-1,2,5-thiadiazole-3-amine,
1,2,5-thiadiazol-3-yl
trifluoromethanesulfonate,
amination.
At the present time, there is no convenient method for synthesis of 3-arylamino derivatives of
,2,5-thiadiazole.
We have discovered that triflate 2, obtained from 3-hydroxy-1,2,5-thiadiazole 1, smoothly reacts with
1
aromatic amines to form the previously not easily accessible [1] 3-arylamino derivatives of 1,2,5-thiadiazole 3.
H
OH
N
OTf
N
N
N
Ar
Tf O, Et N
ArNH2
DMSO, 100 C
2
3
o
N
N
N
CH Cl2
2
S
S
S
1
2
3a,b
3
6 4
a Ar = Ph, b Ar = 4-MeC H
The only known example of such a reaction between hetaryl triflates and aromatic amines without using
catalysts [2] is the reaction of quinolin-2-yl trifluoromethanesulfonate and aniline.
1
19
1
The H and F NMR spectra were taken on a Varian VXR-300, internal standard TMS ( H) and FCCl
3
1
9
(
F).
1
5
1
,2,5-Thiadiazol-3-yl Trifluoromethanesulfonate (2). Yield 85%; mp 50-52°C (15 torr), n 1.4368,
D
1
5
1
19
d4 1.6. H NMR spectrum (299 MHz, CDCl ), δ, ppm: 8.45 (1H, s, H-4). F NMR spectrum (282 MHz,
3
CDCl ), δ, ppm: -72.0 (3F, s, CF ). Found, %: C 15.28; H 0.39; F 24.11; N 11.85; S 27.1. C HF N O S .
3
3
3
3
2
3 2
Calculated, %: C 15.39; H 0.43; F 24.34; N 11.96; S 27.38.
N-Phenyl-1,2,5-thiadiazole-3-amine (3a). Yield 64%; mp 80-82°C; according to data in [1], mp 80°C.
H NMR spectrum (299 MHz, CDCl ), δ, ppm (J, Hz): 6.99 (1H, br. s, NH); 7.07 (1H, t, J = 7.2, C ); 7.36
2H, dd, J = 7.2, J = 8.1, C H ); 7.5 (2H, t, J = 8.1, C H ); 8.08 (1H, s, H-4).
1
3
6 5
H
(
6
5
6
5
1
N-(4-Methylphenyl)-1,2,5-thiadiazole-3-amine (3b). Yield 52%; mp 96-98°C. H NMR spectrum
(
299 MHz, CDCl ), δ, ppm (J, Hz): 2.33 (3H, s, CH ); 6.9 (1H, br. s, NH); 7.17 (2H, d, J = 8.2, Ar); 7.37 (2H, d,
3
3
J = 8.2, Ar); 8.05 (1H, s, H-4). Found, %: C 56.52; H 4.74; N 21.97; S 16.76. C H N S. Calculated, %: C 56.38;
9
9
3
H 4.78; N 21.71; S 16.89.
_
_________________________________________________________________________________________
Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kiev 02660; e-mail;
ypus@email.com. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, p. 924, June, 2005. Original
article submitted December 29, 2004.
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04
0009-3122/05/4106-0804©2005 Springer Science+Business Media, Inc.

REFERENCES
1
2
.
.
J. Rokach, P. Hamel, Y. Girard, and G. Reader, J. Org. Chem., 44, 1118 (1979).
S. Cacchi, A. Carangio, G. Fabrizi, L. Moro, and P. Pace, Synlett, 12, 1400 (1997).
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