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3.6.1. 7,7-Dimethyl-5-oxo-2-(phenyl)-5,6,7,8-tetrahydro-
quinoline 5a. Yield 94%, mp 65–67 ꢀC (MeOH); IR (KBr)
vmax 3059, 2950, 2867, 1678, 1581, 1446, 1395, 1304,
150 (100), 141 (20), 104 (73), 76 (31), 43 (100). Anal. Calcd
for C17H16N2O3: C, 68.90; H, 5.44; N, 9.45. Found: C,
68.99; H, 5.36; N, 9.50.
1
1186, 1122, 837, 778; H NMR (300 MHz, CDCl3, TMS)
d 1.15 (6H, s), 2.02 (2H, s), 3.08 (2H, s), 7.49 (3H, m),
7.70 (1H, d, J¼7.5 Hz), 8.05 (2H, m), 8.26 (1H, d,
J¼8.3 Hz); 13C NMR (50 MHz, CDCl3) d 25.2, 28.0, 32.6,
46.4, 51.7, 118.4, 125.2, 127.1, 128.5, 129.6, 136.7, 138.1,
160.6, 162.0, 197.3; MS (EI) m/z 251 (M+, 76%), 236
(12), 223 (23), 208 (7), 195 (100), 167 (28), 141 (23), 77
(10). Anal. Calcd for C17H17NO: C, 81.24; H, 6.82; N,
5.57. Found: C, 81.19; H, 6.79; N, 5.66.
3.6.6. 7,7-Dimethyl-5-oxo-2-(4-methoxyphenyl)-5,6,7,8-
tetrahydroquinoline 5f. Yield 90%, mp 125 ꢀC (MeOH);
IR (KBr) vmax 3071, 2959, 2932, 2840, 1676, 1580, 1510,
1
1447, 1307, 1254, 1173, 1028, 830, 809, 759; H NMR
(300 MHz, CDCl3, TMS) d 1.15 (6H, s), 2.52 (2H, s), 3.05
(2H, s), 3.90 (3H, s), 6.95 (2H, d, J¼8.7 Hz), 7.65 (1H, d,
J¼8.0 Hz), 8.05 (2H, d, J¼8.7 Hz), 8.25 (1H, d, J¼8.0 Hz);
13C NMR (50 MHz, CDCl3) d 28.2, 32.8, 46.6, 51.9, 55.2,
113.5, 114.1, 117.7, 124.8, 128.7, 130.4, 130.8, 135.0,
161.2, 162.2, 197.6; MS (EI) m/z 281 (M+, 100%), 267 (6),
254 (8), 239 (8), 226 (61), 183 (11), 151 (28), 136 (95),
128 (22), 109 (10), 105 (10), 89 (35), 77 (44), 52 (35), 42
(55). Anal. Calcd for C18H19NO2: C, 76.84; H, 6.81; N,
4.98. Found: C, 76.73; H, 6.88; N, 5.01.
3.6.2. 7,7-Dimethyl-5-oxo-2-(4-methylphenyl)-5,6,7,8-
tetrahydroquinoline 5b. Yield 91%, mp 120 ꢀC (MeOH);
IR (KBr) vmax 3028, 2951, 2926, 2868, 1676, 1581, 1448,
1
1387, 1303, 1180, 802, 757; H NMR (300 MHz, CDCl3,
TMS) d 1.15 (6H, s), 2.42 (3H, s), 2.53 (2H, s), 3.10 (2H,
s), 7.25 (2H, d, J¼7.9 Hz), 7.65 (1H, d, J¼8.3 Hz), 7.95
(2H, d, J¼8.3 Hz), 8.25 (1H, d, J¼8.3 Hz); 13C NMR
(50 MHz, CDCl3) d 21.1, 28.1, 32.7, 46.5, 51.9, 119.2,
125.1, 127.1, 129.9, 135.0, 139.9, 150.8, 160.8, 162.1,
197.5; MS (EI) m/z 265 (M+, 40%), 236 (7), 209 (43), 181
(87), 154 (36), 140 (100), 71 (7), 43 (22). Anal. Calcd for
C18H19NO: C, 81.47; H, 7.22; N, 5.28. Found: C, 81.39;
H, 7.29; N, 5.31.
3.6.7. 7,7-Dimethyl-5-oxo-2-(1-naphthyl)-5,6,7,8-tetrahy-
droquinoline 5g. Yield 95% (flash column chromatography
on SiO2, eluting with light petroleum, gave compound 5g
as pale yellow oil); IR (film) vmax 3053, 2956, 2870,
1729, 1686, 1581, 1560, 1508, 1396, 1305, 1115, 848,
1
801, 778, 741, 663; H NMR (300 MHz, CDCl3, TMS)
d 1.20 (6H, s), 2.60 (2H, s), 3.15 (2H, s), 7.45–7.65 (5H,
m), 7.85–7.95 (2H, m), 8.10 (1H, m), 835 (1H, d,
J¼8.3 Hz); 13C NMR (50 MHz, CDCl3) d 28.2, 32.9,
46.5, 52.0, 123.5, 125.1, 125.2, 125.4, 125.9, 126.6,
127.7, 128.4, 129.5, 130.7, 133.9, 134.8, 137.5, 162.1,
163.3, 197.8; MS (EI) m/z 301 (M+, 38%), 217 (11), 171
(16), 156 (50), 138 (11), 128 (71), 118 (57), 106 (46), 89
(27), 66 (51), 64 (93), 42 (100). Anal. Calcd for
C21H19NO: C, 83.69; H, 6.35; N, 4.65. Found: C, 83.61;
H, 6.41; N, 4.71.
3.6.3. 7,7-Dimethyl-5-oxo-2-(4-chlorophenyl)-5,6,7,8-tet-
rahydroquinoline 5c. Yield 97%, mp 105 ꢀC (MeOH); IR
(KBr) vmax 2954, 2929, 2867, 1683, 1576, 1416, 1300,
1
1090, 829, 807, 753; H NMR (300 MHz, CDCl3, TMS)
d 1.15 (6H, s), 2.52 (2H, s), 3.05 (2H, s), 7.42 (2H, d,
J¼8.6 Hz), 7.65 (1H, d, J¼8.3 Hz), 8.0 (2H, d, J¼8.8 Hz),
8.28 (1H, d, J¼8.1 Hz); 13C NMR (50 MHz, CDCl3)
d 28.1, 32.8, 46.5, 51.9, 118.3, 125.6, 128.9, 129.5, 131.1,
135.3, 136.0, 136.6, 159.5, 162.3, 197.5; MS (EI) m/z 285
(M+, 27%), 284 (25), 283 (82), 256 (31), 229 (100), 200
(17), 166 (95), 138 (32), 102 (20), 55 (31), 63 (37). Anal.
Calcd for C17H16ClNO: C, 71.45; H, 5.64; N, 4.90. Found:
C, 71.39; H, 5.59; N, 4.99.
Supplementary data
1H NMR, 13C NMR, EIMS, spectra for enaminones 1a–g,
2,3,6-trisubstituted pyridines 3a–g and 4a–g, tetrahydroqui-
noline-5-ones 5a–g. Supplementary data associated with this
3.6.4. 7,7-Dimethyl-5-oxo-2-(4-bromophenyl)-5,6,7,8-tet-
rahydroquinoline 5d. Yield 96%, mp 132 ꢀC (MeOH); IR
(KBr) vmax 2953, 2928, 2867, 1678, 1574, 1413, 1378,
1299, 1070, 1008, 828, 806, 743; 1H NMR (300 MHz,
CDCl3, TMS) d 1.16 (6H, s), 2.52 (2H, s), 3.08 (2H, s),
7.59 (2H, d, J¼9.0 Hz), 7.66 (1H, d, J¼8.3 Hz), 7.95 (2H,
d, J¼8.3 Hz), 8.28 (1H, d, J¼8.3 Hz); 13C NMR (50 MHz,
CDCl3) d 28.1, 32.8, 46.5, 51.9, 118.3, 124.5, 125.6,
128.8, 129.6, 131.8, 135.3, 137.1, 159.5, 162.3, 197.5; MS
(EI) m/z 329 (M+, 96%), 300 (18), 273 (93), 191 (8), 166
(100), 139 (32), 102 (26), 75 (28), 39 (95). Anal. Calcd for
C17H16BrNO: C, 61.83; H, 4.88; N, 4.24. Found: C, 61.77;
H, 4.91; N, 4.31.
References and notes
1. (a) Henry, G. D. Tetrahedron 2004, 60, 6043 and the references
cited therein; (b) Bagley, M. C.; Chapaneri, K.; Dale, D. W.;
Xiong, X.; Bower, J. J. Org. Chem. 2005, 70, 1389; (c)
Balasubrahmanyam, M.; Keak, J. G. Comprehensive
Heterocyclic Chemistry; Katritzky, A. R., Ed.; Pergamon:
Oxford, 1996; Vol. 5, p 245; (d) Gilchrist, T. L. J. Chem.
Soc., Perkin Trans. 1 1999, 2849; (e) Gilchrist, T. L. J. Chem.
Soc., Perkin Trans. 1 2001, 2491.
2. (a) Joule, J. A.; Smith, G.; Mill, K. Heterocyclic Chemistry, 3rd
ed.; Chapman and Hall: London, 1995; pp 72–119; (b) Li, A.-H.;
Moro, S.; Forsyth, N.; Melman, N.; Ji, X.-D.; Jacobsen, K. A.
J. Med. Chem. 1999, 42, 706; (c) Vacher, B.; Bonnand, B.;
Funes, F.; Jubault, N.; Koek, W.; Assie, M.-B.; Cosi, C.;
Kleven, M. J. Med. Chem. 1999, 42, 1648; (d) Choi, W. B.;
Houpis, I. N.; Churchill, H. R. O.; Molina, A.; Lynch, J. E.;
3.6.5. 7,7-Dimethyl-5-oxo-2-(4-nitrophenyl)-5,6,7,8-tet-
rahydroquinoline 5e. Mp 182 ꢀC (MeOH); IR (KBr) vmax
3076, 2928, 2870, 1688, 1575, 1515, 1419, 1344, 835,
1
732; H NMR (300 MHz, CDCl3, TMS) d 1.18 (6H, s),
2.59 (2H, s), 3.12 (2H, s), 7.80 (1H, d, J¼8.3 Hz), 8.22–
8.40 (5H, m); 13C NMR (50 MHz, CDCl3) d 28.1, 32.8,
46.5, 51.9. 119.3, 123.8, 126.4, 128.1, 129.1, 135.6, 144.0,
148.5, 158.0, 162.5, 197.3; MS m/z 296 (M+, 2%), 240 (3),