5
135.4, 132.9, 132.5, 128.9, 128.5, 126.6, 126.5, 126.4, 125.9,
123.8, 122.3, 115.6, 104.0, 21.5; IR (KBr): 3403, 3031, 2919,
1603, 1487, 1136, 811, 790 cm−1; MS (EI) m/z 233 (M+).
Ethyl 2-methyl-4-p-tolyl-1H-pyrrole-3-carboxylate (2t): m.p.
ACCEPTED MANUSCRIPT
127-128°C; 1H-NMR (400 MHz, CDCl3) δ 8.24 (s, 1 H), 7.28 (d,
J = 8.3 Hz, 2H), 7.13 (d, J = 7.7 Hz, 2H), 6.54 (d, J = 2.3 Hz,
1H), 4.18 (q, J = 7.1 Hz, 2H), 2.52 (s, 3H), 2.35 (s, 3H), 1.18 (t, J
= 7.0 Hz, 3H); 13C-NMR (100 MHz, CDCl3) δ 165.8, 135.9,
135.7, 132.8, 129.2, 128.2, 127.2, 115.2, 110.0, 59.3, 21.1, 14.2,
14.0; IR (KBr): 3335, 1663, 1441, 1292, 1133, 787 cm−1. MS
(EI) m/z 243 (M+).
2-Phenyl-4-o-tolyl-1H-pyrrole (2i): m.p. 108-109 °C (Lit.8g 154-
155 °C); 1H-NMR (400 MHz CDCl3) δ 8.40 (s, 1H), 7.49 (d, J =
7.7 Hz, 2H), 7.43-7.35 (m, 3H), 7.20 (tt, J = 13.4 Hz, 6.1 Hz,
4H), 6.90 (s, 1H), 6.68 (s, 1H), 2.46 (s, 3H); 13C-NMR (100 MHz
CDCl3) δ 135.5, 135.3, 132.5, 131.8, 130.6, 129.2, 128.9, 126.3,
126.1, 126.0, 125.8, 123.8, 117.7, 106.9, 21.4; IR (KBr): 3372,
3013, 2950, 1604, 1488, 1455, 1135, 814, 762 cm−1; MS (EI) m/z
233 (M+).
2-Hexyl-4-phenyl-1H-pyrrole (2m): 1H-NMR (400 MHz
CDCl3) δ 7.82 (s, 1H), 7.49 (t, J = 7.7 Hz, 2H), 7.30 (t, J = 7.7
Hz, 2H), 7.13 (t, J = 7.2 Hz, 1H), 6.90 (s, 1H), 6.22 (s, 1H), 2.56
(t, J = 7.7 Hz, 2H), 1.65-1.58 (m, 2H), 1.33 (m, 6H), 0.89 (t, J =
6.6 Hz, 3H); 13C-NMR (100 MHz CDCl3) δ 136.0, 134.0, 128.5,
125.2, 125.0, 124.8, 112.7, 31.6, 29.5, 29.0, 27.8, 22.6, 14.1. IR
(KBr): 3370, 2927, 1683, 1604, 1525, 1454, 795, 763, 695 cm−1;
MS (EI) m/z 227 (M+).
Ethyl 2-methyl-4-m-tolyl-1H-pyrrole-3-carboxylate (2u): m.p.
89-90 °C; 1H-NMR (400 MHz, CDCl3) δ 8.36 (s, 1 H), 7.25-7.18
(m, 3H), 7.06 (d, J = 6.8 Hz, 1H), 6.53 (d, J = 2.3 Hz, 1H), 4.17
(q, J = 7.2 Hz, 2H), 2.51 (s, 3H), 2.35 (s, 3H), 1.16 (t, J = 7.2 Hz,
3H); 13C-NMR (100 MHz, CDCl3) δ 165.9, 136.8, 136.1, 135.7,
130.0, 127.4, 127.2, 126.9, 126.4, 115.3, 109.9, 59.3, 21.4, 14.1,
13.9; IR (KBr): 3337, 1669, 1442, 1301, 1136, 782 cm−1; MS
(EI) m/z 243 (M+).
Ethyl 2-methyl-4-o-tolyl-1H-pyrrole-3-carboxylate (2v): m.p.
128-130 °C; 1H-NMR (400 MHz, CDCl3) δ 8.23 (s, 1 H), 7.20-
7.13 (m, 4H), 6.45 (d, J = 2.3 Hz, 1H), 4.03 (q, J = 7.2 Hz, 2H),
2.56 (s, 3H), 2.16 (s, 3H), 0.98 (t, J = 7.0 Hz, 3H); 13C-NMR
(100 MHz, CDCl3) δ 165.7, 137.4, 136.3, 135.4, 130.2, 129.0,
126.7, 126.1, 124.8, 114.9, 111.1, 59.0, 20.3, 13.8, 13.8; IR
(KBr): 3352, 1667, 1440, 1296, 1141, 759 cm−1; MS (EI) m/z 243
(M+).
1
3-Methyl-2,4-diphenyl-1H-pyrrole (2n): m.p. 119-123 °C; H-
NMR (400 MHz CDCl3) δ 8.17 (s, 1H), 7.48-7.38 (m, 8H), 7.29-
7.23 (m, 2H), 6.92 (d, J = 2.4 Hz, 1H), 2.34 (s, 1H); 13C-NMR
(100 MHz CDCl3) δ 136.2, 133.5, 129.7, 128.7, 128.3, 128.2,
126.9, 126.8, 126.3, 125.7, 115.9, 113.9, 11.5; IR (KBr): 3454,
3056, 1692, 1603, 1492, 1449, 766, 755, 699 cm−1; MS (EI) m/z
233 (M+).
Acknowledgment
4-Oxo-2,4-diphenylbutanal oxime (4a): m.p. 119-120 °C; 1H-
NMR (400 MHz CDCl3) δ 7.94 (dd, J = 8.4, 1.1 Hz, 2H), 7.61 (d,
J = 4.5 Hz, 1H), 7.55 (t, J = 7.5 Hz, 1H), 7.44 (t, J = 7.7 Hz, 2H),
7.36-7.24 (m, 6H), 4.39-4.35 (m, 1H), 3.78 (dd, J = 17.2, 8.2 Hz,
1H), 3.26 (dd, J = 17.2, 5.7 Hz, 1H); 13C-NMR (100 MHz
CDCl3) δ197.5, 152.6, 140.0, 136.8, 133.1, 128.8, 128.6, 128.2,
128.1, 127.3, 41.2, 41.3; IR (KBr): 3268, 2913, 1690, 1449, 936,
703 cm−1; MS (EI) m/z 235 (M+- H2O).
This work was financially supported by the MEXT-Supported
Program for the Strategic Research Foundation at Private
Universities, Grant-in-Aid for Scientific Research, and the
Kansai University Research Grants: Grant-in-Aid for
Encouragement of Scientists.
References and notes
1. Jones, R. A. Ed. Pyrroles Part II, Wiley, New York, 1992.
2. (a) Fan, H.; Peng, J. N.; Hamann, M. T.; Hu, J. F. Chem. Res.
2008, 118, 264; (b) Grube, A.; Kock, M. Org. Lett. 2006, 8, 4675;
(c) Furstner, A. Angew. Chem. Int. Ed. 2003, 42, 3582; (d) Fujita,
M.; Nakao, Y.; Matsunaga, S.; Seiki, M.; Itoh, Y.; Yamashita, J.;
Von Soest, R. W. M.; Fusetani, N. J. Am. Chem. Soc. 2003, 125,
15700; (e) Boger, D. L.; Boyce, C. W.; Labroli, M. A.; Sehon, C.
A.; Jin, Q. J. Am. Chem. Soc. 1999, 121, 54 and references therein.
3. (a) Weber, L. Curr. Med. Chem. 2002, 9, 2085; (b) Hulme, C.;
Core, V. Curr. Med. Chem. 2003, 10, 51; (c) Roth, B. D. Prog.
Med. Chem. 2002, 40, 1.
4. Lohaya, B. B.; Lohyah, V. Pure. Appl. Chem. 2005, 77, 179.
5. For reviews, see: (a) Dydio, P.; Lichosyt, D.; Jurczak J J. Chem.
Soc. Rev. 2011, 40, 2971; (b) Long, Y.-Z.; Li, M.-M.; Gu, C.;
Wan, M.; Duvail, J.-L.; Liu, Z.; Fan, Z. Prog. Polym. Sci. 2011,
36, 1415; (c) Kim, S. K.; Sessler, J. L. Chem. Soc. Rev. 2010, 39,
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D.; Heeq, M.; Ruth, N.; Jerone, R.; Jerome, C. Chem. Mater.
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Rev. 1997, 97, 207.
6. (a) Bergman, J.; Janosik, T. Comp. Heterocyclic Chem III,
Katritzky, A. R.; Ramsden, C. A.; Scriven, F. F. V. Taylor, R. J.
K. Ed. Elsevier Oxford 2008, Vol 3, p 219; (b) Jones, G. B.;
Chapman, B. J. Comp. Heterocyclic Chem II, Katritzky, A. R.;
Rees, C. W.; Scriven, E. F. V.; Bird, C. W. Ed. Pergamon Oxford
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Heterocyclic Chem II, Katritzky, A. R.; Rees, C. W.; Scriven, E.
F. V.; Bird, C. W. Ed. Pergamon Oxford 1996, Vol 2, p 119.
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Chem. Soc. Rev. 2010, 39, 4402; (b) Belina, F.; Rossi, R.
Tetrahedron 2006, 62, 7213; (c) Ferreira, V. F.; de Souza, M. C.
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Prep. Proced. Int. 2001, 33, 411.
4.3. General Procedure for Selenium-Catalyzed Reaction
of Ethyl 3-Oxobutanoate, Nitro Vinyl Compounds and
Carbon Monoxide. To an autoclave, ethyl acetoacetate (52 mg,
0.4 mmol), vinyl nitro compound (0.4 mmol), selenium (8 mg,
0.1 mmol), and 1-methylpyrrolidine (212 mg, 2.5 mmol), were
added to DMF (2.5 mL). The apparatus was then flushed several
times with carbon monoxide and fully charged with carbon
monoxide (30 atm) at room temperature. The reaction was
carried out at 120 °C for 5 h. The reaction apparatus was then
cooled to room temperature. After the evacuation of the excess
carbon monoxide, the solution was extracted with ethyl acetate.
The organic layer was dried over MgSO4. The resulting mixture
was filtered, and the filtrate was concentrated. Purification of the
residue by silica gel column chromatography afforded the
pyrrole. (Caution: The prepared pyrroles slowly decomposed
during the purification and storing in solution.) The structures of
the products were assigned by their 1H- and 13C-NMR, and mass
spectra. The product was characterized by comparing its spectral
data with those of an authentic sample or previous reports on 2s27
and 2w.28
Ethyl
4-(4-chlorophenyl)-2-methyl-1H-pyrrole-3-carboxylate
(2r): m.p. 165-168 °C; 1H-NMR (400 MHz, CDCl3) δ 8.18 (s,
1H), 7.33-7.26 (m, 4H), 6.58 (d, J = 2.3 Hz, 1H), 4.18 (q, J = 7.2
Hz, 2H), 2.55 (s, 3H), 1.18 (t, J = 7.2 Hz, 3H); 13C-NMR (100
MHz, CDCl3) δ 165.6, 136.3, 134.3, 132.0, 130.1, 127.6, 126.1,
115.4, 109.9, 59.4, 14.2, 14.0; IR (KBr): 3282, 1658, 1298, 1137,
797, 750 cm−1; MS (EI) m/z 263 (M+).