3-(4-Chlorophenyl)-2-(4-methoxyphenyl)-1-methylene-1,2-dihydropyrazino[1,2-a]benzimidazole 4-(3-(4-Chlorophenyl)-1-methylenepyrazino[1,2-a]benzimidazol-2(1H)-yl)phenyl methyl ether AIDS-150399 AIDS150399 NSC687530