. . . . . . . . . . . "Aime Joseph Arsac, Pierre Frank, \"Process for making 2-(4'-aminophenyl) 5-amino benzimidazole.\" U.S. Patent US4109093, issued 1893."@en . . . . . . . "experimental"@en . . . . . . . . . "Benzimidazole"@en . . . . . . . . . . . . . . "51-17-2"@en . . .