concentrated under reduced pressure. After column chromatography, the pure product was obtained as orange-yellow crystals (0.225 g, 50%), mp. 270-272 oC, (Lit. > 250 oC).40
IR . (KBr) cm.-1: 3435, 3045, 2977, 2941, 2362, 1600, 1571, 1519, 1469, 1418, 1375, 1277, 1096, 1048, 987, 828, 749.
1H-NMR (500 MHz, CDCl3): . 8.37-8.39 (d, J = 8.00 Hz, 2H), 7.94-7.95 (d, J = 8.50 Hz, 2H), 7.71- 7.73 (d, J = 8.50 Hz, 2H), 7.46-7.48 (d, J = 8.00 Hz, 2H), 7.28-7.29 (dd, J = 8.50, 1.00 Hz, 2H), 7.12-7.14 (d, J = 8.00 Hz, 2H), 6.88-6.91 (ddd, J = 8.50, 8.00, 1.50 Hz, 2H), 6.37-6.41 (ddd, J = 8.50, 7.00, 1.50 Hz, 2H), 4.25 (s, 6H).
MS (EI): m/z, (%) 439 (21), 438 (63), 423 (28), 395 (28), 380 (24), 350 (25), 203 (22), 195 (30), 181 (36), 180 (34), 175 (100), 174 (40), 168 (24), 111 (22), 97 (33), 85 (43), 84 (22), 83 (43), 71 (43).
Benzo[c]phenanthrene (36) was obtained in 84 % yield (0.125 g) on a 0.65 mmol scale by (method B). It was purified by column chromatography on silica gel using petroleum ether as eluent to afford colorless solid, mp. 68-69 oC (Lit. 67-68 oC).41
IR . (KBr) cm.-1: 3042, 3007, 2926, 1618, 1599, 1518, 1494, 1458, 1418, 832, 806, 744.
1H-NMR (200 MHz, CDCl3): . 9.12-9.16 (d, J = 8.00 Hz, 2H), 8.01-8.05 (dd, J = 8.00, 2.00 Hz, 2H), 7.81-7.89 (dd, J = 8.00 Hz, 4H), 7.58-7.73 (m, 4H).
MS (EI): m/z, (%) 230 (02), 229 (19), 228 (100), 227 (48), 226 (43), 113 (17), 112 (06).
2-Chlorobenzo[c]phenanthrene (37) was obtained in 67% yield (0.10 g) on a 0.567 mmol scale by (method B). It was purified by column chromatography on silica gel using petroleum ether as eluent to afford colorless solid, mp. 62-64 oC (Lit. 61.4-61.8 oC).41
IR . (KBr) cm.-1: 3046, 2924, 1596, 1487, 1440, 1419, 1110, 1092, 1039, 838, 779, 747.
1H-NMR (200 MHz, CDCl3): . 9.11 (d, J = 1.30 Hz, 1H), 9.03-9.06 (d, J = 9.70 Hz, 1H), 8.01-8.03 (dd, J = 7.70, 0.80 Hz, 1H), 7.93-7.95 (d, J = 8.50 Hz, 1H), 7.90-7.93 (d, J = 8.50 Hz, 1H), 7.80- 7.87 (m, 3H), 7.71-7.75 (m, 1H), 7.63-7.66 (m, 1H), 7.56-7.58 (dd, J = 8.50, 2.00 Hz, 1H).
MS (EI): m/z, (%) 265 (06), 264 (32), 263 (20), 262 (100), 228 (10), 227 (57), 226 (84), 225 (21), 224 (23), 113 (72), 112 (33).
Acknowledgements
We wish to thank Department of Science and Technology, New Delhi for the financial support (SR/SI/OC-42/2006; for HRT) and Council of Scientific and Industrial Research, New Delhi for the award of a fellowship (ARC). We are grateful to Prof. B.V. Kamath, Head, Department of Chemistry for the laboratory facilities. We also thank RSIC, Punjab University, Chandigarh and Apicore Pharmaceuticals Ltd. for recording the NMR spectra.
References
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