SE359833

1308048 1,11-Disubstituted-4,41-bipyridylium salts IMPERIAL CHEMICAL INDUSTRIES Ltd 2 Oct 1970 [21 Oct 1969] 51557/69 Heading C2C 1,11-Disubstituted-4,41-bipyridylium salts are prepared by reacting an N-substituted pyridinium salt having a carboxyl group or salt thereof in the 4-position with cyanide ions and subsequently oxidizing the resulting interaction product. The cyanide ions may be added in the form of a cyanide, preferably sodium cyanide, the reaction preferably being carried out under basic conditions at from 25 to 120‹ C. in a polar aprotic solvent. The oxidizing agent may be air, oxygen or an inorganic oxyacid anhydride and is preferably sulphur dioxide, the oxidation is preferably carried out in acid conditions. The interaction product is preferably isolated from the reaction mixture prior to oxidation. The N-substituent on the N-substituted pyridinium salt is preferably an alkyl group or a carbamidoalkyl group.