B. Temelli, C. Unaleroglu / Tetrahedron Letters 46 (2005) 7941–7943
7943
4. (a) Okitsu, O.; Suzuki, R.; Kobayashi, S. J. Org. Chem.
2001, 66, 809–823; (b) Kobayashi, S.; Hachiya, I.; Suzuki,
S.; Moriwaki, M. Tetrahedron Lett. 1996, 37, 2809–2812.
5. (a) Kobayashi, S. Synlett 1994, 689–701; (b) Kobayashi, S.;
Sugiura, M.; Kitagawa, H.; Lam, W. L. Chem. Rev. 2002,
102, 2227–2302.
C3-H), 5.64 (d, J = 9.3, 1H, CH), 5.88 (d, J = 9.3, 1H,
SO2NH), 5.97 (br s, 1H, C4-H), 6.70 (br s, 1H, C5-H), 6.72–
6.74 (m, 1H, Ar–H), 6.81–6.83 (m, 1H, Ar–H), 7.00–7.02
(m, 1H, Ar–H), 7.08 (d, J = 8.2, 2H, Ar–H), 7.16–7.19 (m,
1H, Ar–H), 7.55 (d, J = 8.2, 2H, Ar–H), 8.72 (br s, 1H,
NH); 13C NMR (100 MHz, CDCl3) d: 21.55, 53.85, 55.45,
107.04, 108.26, 111.21, 118.01, 120.87, 126.82, 127.22,
129.09, 129.60, 130.55, 137.86, 142.55, 156.76. Anal. Calcd
for C19H20N2O3S: C, 64.02; H, 5.66; N, 7.86; S, 9.00.
Found: C, 64.11; H, 5.81; N, 7.82; S, 8.75. For 2- and 3-
alkylated pyrroles, see: (b) Kotsuki, H; Nishiuchi, M.;
Kobayashi, S.; Nishizawa, H. J. Org. Chem. 1990, 55,
2969–2972; (c) Jorapur, Y. R.; Lee, C.-H.; Chi, D. Y. Org.
Lett. 2005, 7, 1231–1234.
6. Unaleroglu, C.; Temelli, B.; Demir, A. S. Synthesis 2004,
15, 2574–2578.
7. (a) Experimental procedure for the synthesis of 3a: A
mixture of N-benzylidene-4-methylbenzenesulfonamide 2a
(1 mmol) and Cu(OTf)2 (0.1 mmol) was stirred in 10 mL
THF for 30 min. Next, a solution of pyrrole (1 mmol) in
5 mL THF was added dropwise. The reaction was moni-
tored by TLC and the reaction was complete in 6 h. The
mixture was passed through a short column packed with
silica gel eluting with ethyl acetate to remove the Cu(OTf)2.
The eluent was evaporated under reduced pressure and the
crude product was purified by flash column chromatogra-
phy over silica gel 60 (230–400 mesh, ethyl acetate/hexane,
1:3). Selected data for 3a: Pale yellow viscous oil; Rf: 0.40
(1:3 EtOAc/hexane); IR (KBr) 3458, 2085, 1633, 1390,
8. (a) Wallace, D. M.; Leung, S. H.; Senge, M. O.; Smith, K.
M. J. Org. Chem. 1993, 58, 7245–7257; (b) Lee, C. H.;
Lindsey, J. S. Tetrahedron 1994, 50, 11427–11440; (c)
Shanmugathasan, S.; Edwards, C.; Boyle, R. W. Tetra-
hedron 2000, 56, 1025–1046; (d) Gryko, D. T.; Jadach, K. J.
Org. Chem. 2001, 66, 4267–4275; (e) Geier, G. R.; Chick,
J. F. B.; Callinan, J. B.; Reid, C. G.; Auguscinski, W. P.
J. Org. Chem. 2004, 69, 4159–4169.
1282, 1136, 1080, 1021, 689, 605, 531 cmÀ1 1H NMR
;
(400 MHz, CDCl3) d: 2.38 (s, 3H, CH3), 5.57–5.60 (m, 2H,
C3-H, CH), 5.84 (br s, 1H, SO2NH), 5.97 (br s, 1H, C4-H),
6.66 (br s, 1H, C5-H), 7.11–7.20 (m, 7H, Ar–H), 7.53 (d,
J = 8.4, 2H, Ar–H), 8.76 (br s, 1H, NH); 13C NMR
(100 MHz, CDCl3) d: 21.49, 55.78, 108.20, 118.57, 127.16,
127.38, 127.57, 128.35, 129.05, 129.29, 130.53, 137.47,
138.89, 142.87. Anal. Calcd for C18H18N2O2S: C, 66.23;
H, 5.56; N, 8.58; S, 9.82. Found: C, 66.12; H, 5.63; N, 8.40;
S, 9.73. Selected data for 3c: light brown solid; mp: 132–
133 °C; Rf: 0.34 (1:3 EtOAc/hexane); IR (KBr) 3440, 2954,
2835, 1638, 1491, 1453, 1328, 1247, 1156, 1092, 1023, 909,
9. The spectral data of dipyrromethanes has been reported,
see: (a) Littler, B. J.; Miller, M. A.; Hung, C. H.; Wagner,
R. W.; OÕShea, D. F.; Boyle, P. D.; Lindsey, J. S. J. Org.
Chem. 1999, 64, 1391–1396; (b) Naik, R.; Joshi, P.; Kaiwar,
S. P.; Deshpande, R. K. Tetrahedron 2003, 59, 2207–2213,
Selected data for 4a: yellow viscous oil; Rf: 0.60 (1:3
EtOAc/hexane); IR (KBr) 3449, 2951, 1630, 1510, 1410,
1293, 1225, 1048, 760, 703, 607 cmÀ1; 1H NMR (400 MHz,
CDCl3) d: 5.49 (s, 1H, CH), 5.92 (br s, 2H, C3-H), 6.14 (br
s, 2H, C4-H), 6.67 (br s, 2H, C5-H), 7.22–7.33 (m, 5H, Ar–
H), 7.88 (br s, 2H, N-H); 13C NMR (100 MHz, CDCl3) d:
44.09, 107.45, 108.45, 117.12, 127.03, 128.51, 128.68,
132.36, 142.23.
790, 743, 664, 549 cmÀ1
;
1H NMR (400 MHz, CDCl3) d:
2.37 (s, 3H, CH3), 3.70 (s, 3H, OCH3), 5.51 (br s, 1H,