Synthesis and antiprotozoal activity of novel bis-benzamidino imidazo[1,2-a]pyridines and 5,6,7,8-tetrahydro-imidazo[1,2-a]pyridines
作者:Mohamed A. Ismail、Reem K. Arafa、Tanja Wenzler、Reto Brun、Farial A. Tanious、W. David Wilson、David W. Boykin
DOI:10.1016/j.bmc.2007.10.042
日期:2008.1
acid yielded the 2,6-bis(4-cyanophenyl)-imidazo[1,2-a]pyridine derivatives 4a-d. The bis-amidoximes 5a-d, obtained from 4a-d by the action of hydroxylamine, were converted to the bis-O-acetoxyamidoximes which on catalytic hydrogenation in a mixture of ethanol/ethyl acetate gave the acetate salts of 2,6-bis[4-(amidinophenyl)]-imidazo[1,2-a]pyridines 7a-d. In contrast, catalytic hydrogenation of the
关键的二腈中间体 4a-d 是通过苯甲酰溴 1 和适当的 2-氨基-5-溴吡啶反应生成 3a-d 合成的。3a-d 与 4-氰基苯基硼酸的 Suzuki 偶联产生 2,6-双 (4-氰基苯基)-咪唑并 [1,2-a] 吡啶衍生物 4a-d。通过羟胺的作用从 4a-d 获得的双-酰胺肟 5a-d 被转化为双-O-乙酰氧基酰胺肟,在乙醇/乙酸乙酯的混合物中催化氢化得到 2,6-双的乙酸盐[4-(脒基苯基)]-咪唑并[1,2-a]吡啶7a-d。相反,5a 的双-O-乙酰氧基酰胺肟在冰醋酸中催化氢化得到饱和类似物 2,6-双[4-(脒基苯基)]-5,6,7,8-四氢-咪唑并[1,2 -a]吡啶 8. 酰胺肟 5a-d 的 O-甲基化得到 N-甲氧基脒 6a-d。二脒表现出很强的 DNA 结合亲和力,在体外对 T. br 非常活跃,IC(50) 值在 7 到 38nM 之间,但对 P. f. 的效果较差。IC(50)