2964
M. Campo et al.
LETTER
(10) Li, B.; Franck, R. W.; Capozzi, G.; Menichetti, S.; Nativi, C.
Org. Lett. 1999, 1, 111.
(11) A small amount of the bis-sulfenylated derivative (5–10%)
was also isolated.
(12) The following procedures for the preparation of 3a, by
sulfenylation of 2a with sulfenyl chloride 1, and synthesis of
thiazine 5e, by cycloaddition of an o-iminothioquinone with
p-methoxystyrene (4e), can be regarded as general
procedures as well.
Acknowledgment
Financial support from MIUR (Research project ‘Stereoselezione in
Sintesi Organica, Metodologie ed Applicazioni’ contract
2005035330) is gratefully acknowledged.
References and Notes
(1) Capozzi, G.; Falciani, C.; Menichetti, S.; Nativi, C. J. Org.
Chem. 1997, 62, 2611.
(2) Capozzi, G.; Falciani, C.; Menichetti, S.; Nativi, C.;
Raffaelli, B. Chem. Eur. J. 1999, 5, 1748.
(3) Arnoldi, A.; Bassoli, A.; Merlini, L.; Ragg, E. J. Chem. Soc.,
Perkin Trans. 1 1993, 1359.
(4) Menichetti, S.; Nativi, C.; Sarri, P.; Viglianisi, C. J. Sulfur
Chem. 2004, 25, 317.
Synthesis of N-Thiophthalimide 3a: A solution of
PhthNSCl (1; 0.788 g, 3.47 mmol) in anhyd CHCl3 (10 mL)
was added to a solution of N-tosyl aniline 2a (0.890 g, 2.89
mmol) in anhyd CHCl3 (10 mL). The reaction mixture was
stirred at r.t. for 3.5 h, diluted with CH2Cl2, washed with a
sat. solution of NaHCO3, and H2O, and dried over Na2SO4.
The material obtained after evaporation of the solvent was
purified by flash chromatography on silica gel using CHCl3
as eluent. o-N-Tosyl-N-thiophthalimide 3a was obtained as
a white powder (0.390 g, 73% yield). IR (KBr disc): 3193,
2946, 2845, 1784, 1733, 1728, 1337, 1269, 1158, 1051
cm–1. 1H NMR (400 MHz, CDCl3): d = 9.48 (s, 1 H, NH),
7.86–7.88 (m, 2 H), 7.73–7.75 (m, 4 H), 7.19–7.21 (m, 2 H),
6.86 (d, J = 2.4 Hz, 1 H), 6.15 (d, J = 2.4 Hz, 1 H), 3.83 (s,
3 H), 3.81 (s, 3 H), 2.36 (s, 3 H). 13C NMR (50 MHz,
CDCl3): d = 168.2, 164.4, 162.5, 143.8, 143.6, 135.8, 131.9,
104.8, 134.6, 129.5, 128.6, 127.4, 99.0, 95.4, 56.1, 55.7,
21.6. Anal. Calcd for C23H20O6N2S2: C, 57.01; H, 4.16; N,
5.78. Found: C, 57.40; H, 4.11; N, 5.76.
(5) Song, Z. J.; King, A. O.; Waters, M. S.; Lang, F.; Zewge, D.;
Bio, M.; Leazer, J. L. Jr.; Javadi, G.; Kassim, A.; Tschaen,
D. M.; Reamer, R. A.; Rosner, T.; Chilenski, J. R.; Mathre,
D. J.; Volante, R. P.; Tiller, R. Proc. Natl. Acad. Sci. U.S.A.
2004, 101, 5776; and references cited therein.
(6) (a) Capozzi, G.; Lo Nostro, P.; Menichetti, S.; Nativi, C.;
Sarri, P. Chem. Commun. 2001, 551. (b) Menichetti, S.;
Aversa, M. C.; Cimino, F.; Contini, A.; Tomaino, A.;
Viglianisi, C. Org. Biomol. Chem. 2005, 3, 3066.
(c) Lodovici, M.; Menichetti, S.; Viglianisi, C.; Caldini, S.;
Giuliani, E. Bioorg. Med. Chem. Lett. 2006, 16, 1957.
(d) Amorati, R.; Fumo, M. G.; Pedulli, G. F.; Menichetti, S.;
Pagliuca, C.; Viglianisi, C. Helv. Chim. Acta 2006, 89,
2462. (e) Amorati, R.; Cavalli, A.; Fumo, M. G.; Masetti,
M.; Menichetti, S.; Chiara Pagliuca, C.; Pedulli, G. F.;
Viglianisi, C. Chem. Eur. J. 2007, 13, 8223.
(7) (a) Matsuoka, H.; Ohi, N.; Mihara, M.; Suzuki, H.;
Miyamoto, K.; Maruyama, N.; Tsuji, K.; Kato, N.; Akimoto,
T.; Takeda, Y.; Yano, K.; Kuroki, T. J. Med. Chem. 1997,
40, 105. (b) Cecchetti, V.; Calderone, V.; Tabarrini, O.;
Sabatini, S.; Filipponi, E.; Testai, L.; Spogli, R.; Martinotti,
E.; Fravolini, A. J. Med. Chem. 2003, 46, 3670. (c) Schou,
S. C.; Hansen, H. C.; Tagmose, T. M.; Boonen, H. C. M.;
Worsaae, A.; Drabowski, M.; Wahl, P.; Arkhammar, P. O.
G.; Bodvarsdottir, T.; Antoine, M.-H.; Lebrunb, P.; Hansen,
J. B. Bioorg. Med. Chem. 2005, 13, 141. (d) Rathore, B. S.;
Kumar, M. Bioorg. Med. Chem. 2006, 14, 5678.
(e) Wei Huang, W.; Yang, G.-F. B. Bioorg. Med. Chem.
2006, 14, 8280.
Synthesis of Benzo[b][1,4]thiazine 5e: To a solution of
sulfenamide 3a (0.250 g, 0.52 mmol) in anhyd CHCl3 (4
mL), p-methoxystyrene (4e; 0.103 g, 0.77 mmol) and Et3N
(0.053 g, 0.52 mmol) were added in sequence. The solution
was stirred at 60 °C for 17 h. The crude product was
concentrated and purified by flash chromatography on silica
gel (eluent: CH2Cl2–PE, 8:2) to give thiazine 5e as a yellow
oil (0.200 g, 81% yield). IR (CHCl3): 3017, 3000, 2913,
2836, 1350, 1247, 1165, 1036 cm–1. 1H NMR (400 MHz,
CDCl3): d = 7.50–7.52 (m, 2 H), 7.29–7.32 (m, 2 H), 7.18–
7.20 (m, 2 H), 6.79–6.81 (m, 2 H), 7.04 (d, J = 2.4 Hz, 1 H),
6.29 (d, J = 2.4 Hz, 1 H), 5.72 (app t, X part of an ABX
system, J = 6.0 Hz, 1 H), 3.82 (s, 3 H), 3.754 (s, 3 H), 3.746
(s, 3 H), 3.04 (AB part of an ABX system, JAB = 13.2 Hz, 2
H), 2.38 (s, 3 H). 13C NMR (100 MHz, CDCl3): d = 158.70,
157.55, 155.86, 143.69, 136.25, 134.81, 131.09, 129.44,
127.56, 127.29, 113.80, 110.7, 105.89, 97.05, 58.21, 55.95,
55.61, 55.15, 31.68, 21.59. MS (rel. int.%): m/z (%) = 471
(100), 316 (98) [M+· – tosyl]. Anal. Calcd for C24H25O5NS2:
C, 61.70; H, 5.80; N, 2.88. Found: C, 61.96; H, 5.75; N, 2.96.
(13) Cardullo, F.; Donati, D.; Merlo, G.; Paio, A.; Salaris, M.;
Taddei, M. Synlett 2005, 2996.
(8) To the best of our knowledge only an example of a dienic
o-iminothioquinone has been reported in the literature: Diep,
V.; Dannenberg, J. J.; Franck, R. W. J. Org. Chem. 2003, 68,
7907.
(9) Capozzi, G.; Menichetti, S.; Nativi, C.; Vergamini, C.
Synthesis 1998, 915.
Synlett 2007, No. 19, 2961–2964 © Thieme Stuttgart · New York