Verwendung von Benzimidazolverbindungen als Aufhellungsmittel mit Ausnahme der Behandlung von Textilfasern in der Textilindustrie

摘要

1,125,535. Imidazole derivatives. FARBENFABRIKEN BAYER A.G. 11 Jan., 1967 [14 Jan., 1966], No. 1565/67. Heading C2C. [Also in Divisions C3, C5 and D1] Novel aryl imidazoles of the formula wherein A is the residual member of an aromatic ring system, and Ar and Ar1 are aromatic radicals, the aromatic and heterocyclic rings optionally bearing substituents other than the nitro group, e.g. halogen, cyano, alkylsulphonyl, carboxamido or alkoxycarbonyl, and the corresponding acid addition salts, and quaternary ammonium derivatives in which the 3-position of the imidazole nucleus bears a substituent R which is an alkyl, alkenyl, cycloalkyl or aralkyl radical which is optionally substituted, are prepared by (1) condensing phenylene diamines with furan-2-carboxylic acids or fractional derivatives thereof, (2) condensing phenylene diamines with furan-2-aldehydes and cyclizing the azomethines so produced by means of an oxidizing agent, or (3) when a carboxamido substituent is present, reducing the corresponding nitroderivative in the presence of an acylating agent, and, if desired quaternizing the products or converting the products to addition salts. The compounds are useful as opticalbrightening agents (see Divisions C3, C5 and D1). 2 - (I1 - Phenyl - benzimidazolyl - (21)) - 5 - (41- nitrophenyl)-furan used as a starting material is obtained by condensing 5-(41-nitrophenyl)- furan - 2 - aldehyde with 2 - amino - diphenylamine and cyclizing the azomethine produced.