Copper complexes of carboxamidrazone derivatives as anticancer agents. 3. Synthesis, characterization and crystal structure of [Cu(appc)Cl-2], (appc = N-1(2-acetylpyridine)pyridine-2-carboxamidrazone)

Copper(II) complexes of the derivatives of pyridyl-2-carboxamidrazone [Cu(a ppc)Cl-2] (1) (appc = N-1-(2-acetylpyridine)pyridine-2-carboxamidrazone) an d [Cu(atpc)Cl-2] (2) (ATPC = N-1-(2-acetylthiophene)pyridine-2-carboxamidra zone) have been prepared and characterized by various physicochemical techn iques including electrochemistry, IR and UV-Vis spectroscopy. The crystal s tructure of 1 is reported (space group P2(1)/n, a = 8.2535(6) Angstrom, b = 16.7479(15) Angstrom, c = 10.5320(8) Angstrom). The geometry around copper in 1 is best described as trigonal bipyramidal (tau = 0.58) where the chlo ride ions occupy equatorial positions on the trigonal plane in a cis-config uration and are involved in the hydrogen bonding interactions with the prot ons of the amino group of the neighboring molecules. The in vitro antiproli ferative activity against mouse melanoma cell line B16F10 indicates compoun d 1 to be highly potent, clearly establishing the importance of copper conj ugation in the drug design for melanomal cancers. (C) 2001 Elsevier Science B.V. All rights reserved.