C. Pamp´ın et al. / Tetrahedron Letters 43 (2002) 4551–4553
4553
11. (a) All new compounds gave satisfactory analytical and
spectroscopic data. Selected physical and spectroscopic
data follow. Compound 4a. 1H NMR (l, ppm, CDCl3):
3.78 (s, 3H, -CO2CH3), 6.92 (d, J=16.3 Hz, 1H,
-CHꢀCH-), 7.17–7.35 (m, 5H, 5×Ar-H), 7.47–7.51 (m,
2H, 2×Ar-H), 7.58 (d, J=7.7 Hz, 1H, Ar-H), 7.86 (dd,
J=7.8 and 1.3 Hz, 1H, Ar-H), 8.02 (d, J=16.3 Hz, 1H,
-CHꢀCH-). MS (m/z, %): 238 (M+, 79), 178 (100). Com-
pound 5a. 1H NMR (l, ppm, CDCl3): 4.04 (s, 3H,
-CO2CH3), 7.64–7.70 (m, 3H, 3×Ar-H), 7.87 (d, J=9.4
Hz, 1H, Ar-H), 7.93 (d, J=7.4 Hz, 1H, Ar-H), 8.22 (d,
J=7.4 Hz, 1H, Ar-H), 8.70 (d, J=7.9 Hz, 1H, Ar-H),
8.78 (d, J=9.4 Hz, 1H, Ar-H), 8.92 (d, J=8.4 Hz, 1H,
Ar-H). MS (m/z, %): 236 (M+, 100). Compound 4b. Mp
86–88°C (MeOH). 1H NMR (l, ppm, CDCl3): 3.87 (s,
3H, -CO2CH3), 3.89 (s, 3H, -OCH3), 3.94 (s, 3H, -OCH3),
6.89 (d, J=16.2 Hz, 1H, -CHꢀCH-), 7.10 (s, 1H, Ar-H),
7.22–7.36 (m, 3H, 3×Ar-H), 7.44 (s, 1H, Ar-H), 7.51–7.54
(m, 2H, 2×Ar-H), 8.07 (d, J=16.2 Hz, 1H, -CHꢀCH-).
MS (m/z, %): 298 (M+, 100). Compound 5b. Mp 109–
-OCH3), 4.25 (s, 3H, -OCH3), 7.68–7.74 (m, 2H, 2×Ar-H),
7.98–8.01 (m, 2H, 2×Ar-H), 8.45–8.46 (m, 1H, Ar-H),
8.63 (d, J=9.0 Hz, 1H, Ar-H), 8.77 (bs, 1H, Ar-H), 9.69
(bs, 1H, Ar-H), 9.77 (d, J=8.3 Hz, 1H, Ar-H). MS (m/z,
%): 289 (M+, 2), 58 (100).
12. Karmakar, A. C.; Kar, G. K.; Ray, J. K. J. Chem. Soc.,
Perkin Trans. 1 1991, 1997.
13. For previous syntheses of o-styrylbenzoic acids, see Ref.
1. See also: (a) Kim, B. M.; Park, J. K. Bull. Korean
Chem. Soc. 1999, 20, 744; (b) Noda, M. Chem. Pharm.
Bull. 1998, 46, 1157; (c) Zehnter, R.; Gerlach, H. Tetra-
hedron: Asymmetry 1995, 6, 2779; (d) Yoshikawa, M.;
Harada, E.; Yagi, N.; Okuno, Y.; Muraoka, O.; Aoyama,
H.; Murakami, N. Chem. Pharm. Bull. 1994, 42, 721; (e)
Mal, D.; Majumdar, G.; Pal, R. J. Chem. Soc., Perkin
Trans. 1 1994, 1115; (f) Bowden, K.; Ghadir, K. J. Chem.
Soc., Perkin Trans. 2 1990, 1333; (g) Lazer, E. S.; Wong,
H. C.; Wegner, C. D.; Graham, A. G.; Farina, P. R. J.
Med. Chem. 1990, 33, 1892; (h) Eicher, T.; Tiefensee, K.;
Pick, R. Synthesis 1988, 525; (i) Bellinger, G. C. A.;
Campbell, W. E.; Giles, R. G. F.; Tobias, J. D. J. Chem.
Soc., Perkin Trans. 1 1982, 2819; (j) Meyers, A. I.; Gabel,
R.; Mihelich, E. D. J. Org. Chem. 1978, 43, 1372.
14. (a) Citterio, A.; Pesce, L.; Sebastiano, R.; Santi, R.
Synthesis 1990, 142; (b) Caluwe, P.; Pepper, T. J. Org.
Chem. 1988, 53, 1786; (c) Rubin, M. B.; Welner, S. J.
Org. Chem. 1980, 45, 1847.
1
111°C (AcOEt). H NMR (l, ppm, CDCl3): 3.97 (s, 3H,
-CO2CH3), 4.02 (s, 3H, -OCH3), 4.06 (s, 3H, -OCH3),
7.60–7.65 (m, 2H, 2×Ar-H), 7.69 (d, J=9.3 Hz, 1H,
Ar-H), 7.84–7.88 (m, 1H, Ar-H), 7.92 (s, 1H, Ar-H), 8.65
(d, J=9.3 Hz, 1H, Ar-H), 9.62–9.66 (m, 1H, Ar-H). MS
(m/z, %): 296 (M+, 100). Compound 9f. Mp 152–154°C
(MeOH). 1H NMR (l, ppm, CDCl3): 4.04 (s, 3H,