Mar-Apr 2002
Tin(II) Chloride-Mediated Synthesis of 2-Substituted Benzoxazoles
423
13
(m, 1H), 7.95-7.98 (m, 2H), 8.29-8.32 (m, 1H), 8.76 (s, 1H);
1H), 8.20-8.23 (m, 2H); C NMR (CDCl ): δ 111.3, 120.0,
3
13
C NMR (CDCl ): δ 110.6, 120.0, 123.9, 124.4, 124.6, 125.2,
125.3, 126.7, 127.7, 128.9, 130.0, 131.9, 143.2, 149.3, 164.3.
3
126.9, 127.8, 127.9, 128.1, 128.8, 128.9, 133.0, 134.7, 142.2,
150.8, 163.2.
Acknowledgment.
The present work was supported by the Korea Research
Foundation Grant (KRF-2001-015-DP0296). C.S.C. gratefully
acknowledges a MOE-KRF Research Professor Program (2001-
050-D00015).
2-(2-Furanyl)benzoxazole.
This compound was obtained as white crystals, mp 84-86°
(hexane) (lit [3] mp 86.5-87.5°); H NMR (CDCl ): δ 6.62 (dd,
J = 3.5 and 2.0 Hz, 1H), 7.28 (d, J = 3.5 Hz, 1H), 7.32-7.38 (m,
1
3
2H), 7.54-7.59 (m, 1H), 7.65-7.67 (m, 1H), 7.73-7.78 (m, 1H);
REFERENCES AND NOTES
13
C NMR (CDCl ): δ 110.6, 112.3, 114.3, 120.1, 124.8, 125.3,
3
141.6, 142.6, 145.7, 150.1, 155.3.
[1] D. W. Heine, R. J. Alheim and J. J. Leavitt, J. Am. Chem.
Soc., 79, 427 (1957).
2-(2-Thiophenyl)benzoxazole.
[2] Y. Kanaoka, T. Hamada and O. Yonemitsu, Chem. Pharm.
Bull., 18, 587 (1970).
[3] M. Terashima, M. Ishii and Y. Kanaoka, Synthesis, 484
(1982).
[4] K. Nakagawa, H. Onoue and J. Sugita, Chem. Pharm.
Bull., 12, 1135 (1964).
[5] T. Kondo, S. Yang, K.-T. Huh, M. Kobayashi, S. Kotachi
and Y. Watanabe, Chem. Lett., 1275 (1991).
[6] R. J. Perry, B. D. Wilson and R. J. Miller, J. Org. Chem.,
57, 2883 (1992).
[7] R. J. Perry and B. D. Wilson, J. Org. Chem., 57, 6351
(1992).
[8] C. S. Cho, H. K. Lim, S. C. Shim, T. J. Kim and S. C.
Shim, Chem. Commun., 995 (1998).
[9] C. S. Cho, J. H. Kim and S. C. Shim, Tetrahedron Lett., 41,
1811 (2000).
[10] C. S. Cho, J. H. Kim, T.-J. Kim and S. C. Shim,
Tetrahedron, 57, 3321 (2001).
This compound was obtained as white crystals, mp 104-105°
1
(hexane) (lit [21] mp 107°); H NMR (CDCl ): δ 7.18 (dd, J = 5.0
3
and 3.5 Hz, 1H), 7.31-7.36 (m, 2H), 7.52-7.56 (m, 2H), 7.71-7.76
13
(m, 1H), 7.91 (dd, J = 3.5 and 1.0 Hz, 1H); C NMR (CDCl ): δ
3
110.4, 119.8, 124.7, 125.0, 128.2, 129.6, 130.0, 130.2, 142.0,
150.4, 159.0.
2-(2-Styryl)benzoxazole.
This compound was obtained as white crystals, mp 80-82°
1
(hexane) (lit [3] mp 80.5-82°); H NMR (CDCl ): δ 7.07 (d, J =
3
16.6 Hz, 1H), 7.30-7.44 (m, 5H), 7.50-7.54 (m, 1H), 7.58-7.60
13
(m, 2H), 7.69-7.74 (m, 1H), 7.78 (d, J = 16.6 Hz, 1H); C NMR
(CDCl ): δ 110.3, 113.9, 119.9, 124.5, 125.2, 127.6, 129.0, 129.8,
3
135.1, 139.5, 142.2, 150.4, 162.8.
2-Benzylbenzoxazole [5].
1
This compound was obtained as pale yellow oil; H NMR
(CDCl ): δ 4.26 (s, 2H), 7.24-7.39 (m, 7H), 7.42-7.46 (m, 1H),
[11] C. S. Cho, T. K. Kim, S. W. Yoon, T.-J. Kim and S. C.
Shim, Bull. Korean Chem. Soc., 22, 545 (2001).
[12] C. S. Cho, B. H. Oh and S. C. Shim, Tetrahedron Lett., 40,
1499 (1999).
[13] C. S. Cho, B. H. Oh and S. C. Shim, J. Heterocyclic
Chem., 36, 1175 (1999).
[14] C. S. Cho, B. H. Oh, S. C. Shim and D. H. Oh, J.
Heterocyclic Chem., 37, 1315 (2000).
[15] C. S. Cho, J. S. Kim, B. H. Oh, T.-J. Kim and S. C. Shim,
Tetrahedron, 56, 7747 (2000).
3
13
7.66-7.70 (m, 1H); C NMR (CDCl ): δ 35.2, 110.4, 119.8,
3
124.1, 124.6, 127.3, 128.8, 128.9, 134.7, 141.3, 151.0, 165.1.
2-Propylbenzoxazole [5].
1
This compound was obtained as pale yellow oil; H NMR
(CDCl ): δ 1.05 (t, J = 7.4 Hz, 3H), 1.89-1.95 (m, 2H), 2.91 (t, J
3
= 7.4 Hz, 2H), 7.27-7.30 (m, 2H), 7.46-7.48 (m, 1H), 7.66-7.68
13
(m, 1H); C NMR (CDCl ): δ 14.1, 20.6, 30.9, 110.6, 119.9,
3
124.4, 124.8, 141.8, 151.2, 167.6.
[16] C. S. Cho, B. H. Oh, J. S. Kim, T.-J. Kim and S. C. Shim,
Chem. Commun., 1885 (2000).
2-Phenyl-5-methylbenzoxazole.
[17] C. S. Cho, T. K. Kim, T.-J. Kim, S. C. Shim and N. S.
Yoon, J. Heterocyclic Chem., in press.
[18] C. S. Cho, J. S. Kim, H. S. Kim, T.-J. Kim and S. C. Shim,
Synth. Commun., 32, 3791 (2001).
[19] G. L. Tullos, J. M. Powers, S. J. Jeskey and L. J. Mathias,
Macromolecules, 32, 3598 (1999).
[20] M. I. El-Sheikh, A. Marks and E. R. Biehl, J. Org. Chem.,
46, 3256 (1981).
[21] E. Tauer and K. H. Grellmann, J. Org. Chem., 46, 4252
(1981).
[22] R. S. Varma and D. Kumar, J. Heterocyclic Chem., 35,
1539 (1998).
This compound was obtained as white crystals, mp 101-102°
1
(hexane) (lit [22] mp 102°); H NMR (CDCl ): δ 2.48 (s, 3H),
3
7.14-7.16 (m, 1H), 7.44 (d, J = 8.5 Hz, 1H), 7.49-7.53 (m, 3H),
13
7.55 (s, 1H), 8.21-8.26 (m, 2H); C NMR (CDCl ): δ 21.5,
3
109.9, 119.9, 126.2, 127.3, 127.5, 128.9, 131.4, 134.4, 142.3,
149.0, 163.1.
2-Phenyl-5-chlorobenzoxazole.
This compound was obtained as white crystals, mp 102°
1
(hexane) (lit [1] mp 101.1-102.1°); H NMR (CDCl ): δ 7.30 (dd,
3
J = 8.5 and 2.0 Hz, 1H), 7.46-7.57 (m, 4H), 7.73 (d, J = 2.0 Hz,