2’-(3’’,4’’-Methylenedioxyphenyl)-imidazo[4’,5’-f]-2,9-dimethyl-1,10-phenanthroline

Li-Feng Tan, Hui-Chao*, Xiang-Li Wang and Liang-Nian Ji*

Department of Chemistry, Sun Yat-Sen University, Guangzhou 510275, P. R. China.

Fax: +86-20-84035497, E-mail: [email protected]; [email protected]

Received: 14 October 2003 / Accepted: 23 February 2004 / Published: 24 February 2004 

Keywords: polypyridyl ligand; 2,9-dimethyl-1,10-phenanthroline; imidazole

2,9-dimethyl-1,10-phenanthroline-5,6-dione was synthesized by the procedure for the preparation of 1,10-phenanthroline-5,6-dione [1]. A mixture of 3,4-methylenedioxy- benzaldehyde (0.45 g, 3 mmol), 2,9-dimethyl-1,10-phenanthroline-5,6-dione (0.714 g, 3 mmol), ammonium acetate (4.62 g, 60 mmol) and glacial acetic acid (30 cm³) was refluxed with stirring at 130 ^oC for 2 hours. The cooled solution was filtered, diluted with water (ca, 40 cm³) and neutralized with concentrated aqueous ammonia. The orange precipitate was collected and purified by column chromatography on alumina with ethanol-toluene (16:1 v/v) as eluent. The title compound was obtained as amorphous yellow solid (0.52 g), Yield: 47%.

Elemental analysis: Found C, 71.48; H, 4.13; N, 14.97. Calc for C₂₂H₁₆N₄O₂ C, 71.73; H, 4.38; N, 15.21.

¹H NMR (500 MHz, d₆-DMSO): δ14.1 (br, s, 1H), 8.90 (d, 2H), 7.84 (m, 2H), 7.81 (d, 1H), 7.79 (d, 1H), 7.18 (d, 1H), 6.09 (s, 2H), 2.50 (s, 6H).

IR (KBr, cm^-1): 542(w), 629(w), 731(w), 818(s), 871(w), 931(m), 1038(s), 1102(w), 1242(s), 1351(m), 1445(s), 1472(s), 1497(s), 1585(m), 1623(w), 2776(w), 2890(w), 3067(w).

FAB-MS ([M+1]⁺): 369.

Acknowledgement

Support for this research provided by the National Natural Science Foundation of China, the National Science Foundation of Guangdong Province and Research Fund of Royal Society of Chemistry U.K. is gratefully acknowledged.

Reference

1. M. Yamada, Y. Tanaka, Y. Yoshimoto, S. Kuroda, and I. Shimao, Bull. Chem. Soc. Jpn. 1992, 65, 1006.

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