Stilbene compounds
AssigneeCiba-Geigy Corporation
InventorsGeza Kormany, Guglielmo Kabas, Hans Schlapfer, Adolf Emil Siegrist
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Abstract
Stilbene compounds of the formula ##STR1## wherein R denotes the radical ##STR2## and wherein the rings A, B, C, D and E can carry non-chromophoric substituents are useful for the optical brightening of organic materials.
Claims18
Stilbene compounds of the formula ##STR56## wherein R.sub.1 denotes hydrogen, chlorine, alkyl with 1 to 8 carbon atoms, alkoxy with 1 to 4 carbon atoms, alkoxycarbonyl with 1 to 4 carbon atoms in the alkoxy rest, cyanoalkyl, alkylsulphonyl, phenylalkyl with 1 to 3 carbon atoms in the alkyl part, sulfamoyl, cyclohexyl, phenyl, phenylsulphonyl or benzyl, R.sub.2 denotes hydrogen or alkyl with 1 to 4 carbon atoms and R' denotes a radical ##STR57## wherein R.sub.3 represents hydrogen, chlorine, alkyl with 1 to 4 carbon atoms, alkoxy with 1 to 4 carbon atoms, carbalkoxy with 2 to 5 carbon atoms, unsubstituted sulphamoyl or sulphamoyl which is monosubstituted or disubstituted by alkyl or hydroxyalkyl with 1 to 4 carbon atoms or represents alkylsulphonyl with 1 to 4 carbon atoms.
Process for the manufacture of stilbene compounds of the formula ##STR75## wherein R denotes the radical ##STR76## and wherein the rings, A, B, C, D and E can possess nonchromophoric substituents selected from the group consisting of chlorine, alkyl with 1 to 8 carbon atoms, alkoxy with 1 to 4 carbon atoms, alkoxycarbonyl with 1 to 4 carbon atoms in the alkoxy rest, cyanoalkyl, alkylsulphonyl with 1 to 4 carbon atoms in the alkyl rest,
- phenylalkyl with 1 to 3 carbon atoms in the alkyl part, sulfamoyl, cyclohexyl, phenyl, phenylsulphonyl or benzyl, which comprises reacting a methyl compound of the formula ##STR77## in dimethylformamide as the reaction medium and in the presence of a strongly basic alkali metal compound, with a Schiff's base of the formula ##STR78## wherein A, B, C and R have the abovementioned meaning and Ar denotes an aromatic radical, the reaction mixture being irradiated with an effective amount of UV light to initiate the reaction.
Dependencies are inferred from the claim text.