New ligands, viz., thioether-containing beta-aminovinyl ketones, and Ni-II complexes with these ligands were synthesized. The compounds were characterized by X-ray diffraction analysis, EXAFS, NMR, and IR spectroscopy, and magnetochemistry.
Tetradentate ligands are used to form neutral 99m-technetium complexes which may be useful as radiopharmaceuticals e.g. as brain imaging agents. The ligands have the structure ##STR1## where n is 2 or 3, m is 0-4, R is H or substituted or unsubstituted C.sub.1 -C.sub.6 alkyl, provided that one CR.sub.2 group adjacent the starred nitrogen atom represents CO and forms with the adjacent N atom, a --CONH-- amide group, Y is unsubstituted or substituted C.sub.1 -C.sub.6 alkyl, and one of X and X' represents H or a labile thiol protecting group while the other is unsubstituted or substituted C.sub.1 -C.sub.6 alkyl, alkenyl or alkynyl.
2-Amino-4<i>H</i>-3,1-benzoxazin-4-ones as Inhibitors of C1r Serine Protease
作者:Sheryl J. Hays、Bradley W. Caprathe、John L. Gilmore、Nilam Amin、Mark R. Emmerling、Walter Michael、Ravi Nadimpalli、Rathna Nath、Kadee J. Raser、Daniel Stafford、Desiree Watson、Kevin Wang、Juan C. Jaen
DOI:10.1021/jm970394d
日期:1998.3.1
A series of 2-amino-4H-3,1-benzoxazin-4-ones have been synthesized and evaluated as inhibitors of the complement enzyme C1r. C1r is a serine protease at the beginning of the complement cascade, and complement activation by beta-amyloid may represent a major contributing pathway to the neuropathology of Alzheimer's disease. Compounds such as 7-chloro-2-[(2-iodophenyl)amino]benz[d][1,3]oxazin-4-one (32) and 7-methyl-2-[(2-iodophenyl)amino]benz[d] 4-one (37) show improved potency compared to the reference compound FUT-175. Many of these active compounds also possess increased selectivity for C1r compared to trypsin and enhanced hydrolytic stability relative to 2-(2-iodophenyl)-4H-3,1-benzoxazin-4-one (1).
SARMA P. K.; BAROOAH S. K.; GOGOI B. D., CURR. SCI. (INDIA). 1977,