Synthesis and Transformations of 2-Amino-1-(4,5-Dihydro-1H-imidazol-2-yl)benzimidazoles. A Route to 2,3-Dihydrobenzo[4,5]imidazo[1,2-c]imidazo[1,2-a][1,3,5]triazine Ring System
摘要:
Starting from 3-(4,5-dihydro-1H-imidazol-2-yl)-2-oxo-2,3-dihydrobenzimidazole-1-carbonitriles (la-e) the 2-amino-1-(4,5-dihydro-1H-imidazol-2-yl)benzimidazoles (2a-e) and 1-(4,5-dihydro-1H-imidazol-2-yl)-2-oxo-2,3-dihydrobenzimidazoles (3a-e) have been synthesized. Cyclocondensation of 2a with acetic anhydride or acyl chlorides gave novel functionalized 2,3-dihydrobenzo[4,5]imidazo[1,2-c]imidazo[1,2-a]triazines (4a-d).
A series of novel N-(4,5-dihydroimidazol-2-yl)-1,3-dihydrobenzimidazole derivatives 2a-d, 3a-d and 4a-p were prepared and their structure was determined by IR and NMR spectroscopic data as well as X-ray analysis of carbonitrile 2a. The compounds were studied as potential inhibitors of the human blood platelet aggregation induced by adrenaline or ADP. Compounds of type 3 proved efficacious for the reduction of arterial blood pressure upon intravenous administration to normotensive rats.