Abstract: Novel stilbene compounds of the formula ##STR1## in which R.sub.1 and R.sub.2 independently of one another are hydrogen or chlorine and A is a mono-nuclear or poly-nuclear aromatic heterocyclic structure which contains oxygen atoms or oxygen and nitrogen atoms and is unsubstituted or substituted by non-chromophoric substituents, as well as their use in a process for optically brightening organic material are disclosed.

Abstract: Novel stilbene compounds of the formula ##STR1## in which R.sub.1 and R.sub.2 independently of one another are hydrogen or chlorine and A is a mono-nuclear or poly-nuclear aromatic heterocyclic structure which contains oxygen atoms or oxygen and nitrogen atoms and is unsubstituted or substituted by non-chromophoric substituents, as well as their use in a process for optically brightening organic material are disclosed.

Abstract: A new process for the manufacture of cyanosubstituted stilbene compounds, new stilbene compounds as well as their use as fluorescent brighteners or as intermediates for the manufacture of fluorescent brighteners are provided.

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.

Abstract: Process for the manufacture of styrene compounds of the formula ##STR1## wherein A denotes one of the ring systems ##STR2## and wherein R.sub.1 denotes hydrogen, alkyl with 1 to 8 carbon atoms, cyclohexyl, phenylalkyl with 1 to 3 carbon atoms in the alkyl part, phenyl, alkoxy with 1 to 4 carbon atoms, or chlorine, or, conjointly with R.sub.2, denotes alkylene with 3 or 4 carbon atoms, R.sub.2 denotes hydrogen or alkyl with 1 to 4 carbon atoms or, conjointly with R.sub.1, denotes alkylene with 3 or 4 carbon atoms, R.sub.3 denotes hydrogen or methyl, R.sub.4 denotes hydrogen, m-methyl, alkyl with 2 to 8 carbon atoms, phenyl, alkoxy with 1 to 4 carbon atoms, or chlorine, or, conjointly with R.sub.5, denotes a fused benzene ring, R.sub.5 denotes hydrogen or chlorine or, conjointly with R.sub.4, denotes a fused benzene ring, X.sub.1 denotes hydrogen, alkyl with 2 to 4 carbon atoms, alkoxy with 1 to 4 carbon atoms or chlorine, X.sub.

Abstract: Styrene compounds of the formula ##STR1## wherein Q denotes one of the ring systems of the formulae ##STR2## wherein M represents oxygen or sulphur, Z represents hydrogen, lower alkyl or phenyl and n represents the number 1 or 2 and the rings A and B can each contain 1 to 3 non-chromophoric substituents.

Abstract: Stilbene compounds of the formula ##STR1## wherein Q denotes the 1,3,4-oxadiazol-2,5-ylene or 1,2,4-oxadiazol-3,5-ylene radical and Q.sub.1 denotes one of the radicals ##STR2## and the rings A, B, C, D and E can each contain 1 to 3 non-chromophoric substituents.

Abstract: A new process for the manufacture of cyano-substituted stilbene compounds, new stilbene compounds as well as their use as fluorescent brighteners or as intermediates for the manufacture of fluorescent brighteners are provided.

Abstract: The invention provides a new process for the manufacture of aromatic compounds which at least once contain a benzene ring of an aromatic carbocyclic ring system bonded by an ethylene double bond in conjugation with a further aromatic ring system, i.e. contain the stilbene skeleton or stilbene analogon as central structural element, as well as certain classes of new compounds of this type. The process is characterized by the reaction of a Schiff base of an aromatic aldehyde with an aromatic carbocyclic six-membered ring compound which contains one to four methyl groups bonded to ring carbon atoms of a benzene ring, which furthermore contains aromatic rings which are exclusively six-membered carbocyclic rings, and wherein those benzene rings whose methyl groups are to be caused to react are free of other substituents which contain atoms which are replaceable by alkali metal. The reaction is carried out in the presence of (a) a strongly basic alkali compound and (b) an N-dialkyl-acylamide as solvent.

Abstract: The present invention provides the new bis-stilbene compounds, which are useful as optical brighteners and correspond to the formulaR.sub.1 -- CH = CH -- X -- CH = CH -- R.sub.2in which X represents a diphenyl residue bound in positions 4 and 4' to the =CH-- groups; R.sub.1 and R.sub.2 independently of each other, each represents a monocyclic benzene residue, a diphenyl, naphthyl or pyridyl residue, and in which at least one of the cyclic systems R.sub.1, R.sub.2, X contains a possibly functionally modified sulphonic acid group, a sulphone group, a possibly functionally modified carboxylic acid group, a nitrile, hydroxyl, mercapto or methyl group.