Patent GB-1132314-A (GB)
Title: Triazolyl stilbene derivatives and their use as brightening agents
Inventor: DORLARS ALFONS
IPC: D06L4/60
Filed: 1967-01-18
Abstract: 1,132,314. Triazolyl stilbene derivatives. FARBENFABRIKEN BAYER A.G. 18 Jan., 1967 [18 Jan., 1966; 17 Feb., 1966], No. 2601/67. Heading C2C. [Also in Divisions C3, C4 and D1] The invention comprises compounds of the formula where R 1  represents halogen or a cyano, acylamino, carboxy, carboxylic ester, or substituted or unsubstituted carboxylic amide group, R 2  represents a substituted or unsubstituted aryl group, X 1  and X 2  independently represent hydrogen or a sulpho, sulphonic acid ester, a substituted or unsubstituted sulphonic acid amide, an alkyl sulphone, aryl sulphone, a carboxy, carboxylic ester, substituted or unsubstituted carboxylic amide or cyano group, and Y represents hydrogen, halogen or an acylamino, or substituted or unsubstituted triazolyl, ben otriazolyl, naphthotriazolyl or pyrazolyl group, and the alkali metal or amine salts of those compounds in which R 1  and/or X 1  and/or X 2  are carboxy and/or sulpho groups. The compounds can be prepared by a variety of methods, (1) by condensing a bis-hydrazinostilbene of the formula with a 1,2,4-oxadiazole of the Formula III in which R 3  represents a substituted or unsubstituted alkyl or aryl radical, to yield a bishydrazone which is converted by known methods to compounds of the formula in which the acylamino groups may be hydrolysed to free amino groups which may then be acylated to give different acylamino groups or diazotized and converted to halogen or cyano groups by the Sandmeyer reaction, (2) by coupling the diazo compounds of amines of the Formula V with α-nitro-ketoximes of the Formula VI to yield bis-azo compounds which are converted by known methods, e.g. by treatment with acid, to the corresponding bis-nitro-triazolyl-(2)- stilbenes which on reduction yield to corresponding amines; the amines can be reacted as in (1), (3) by coupling the diazo compounds of the amine V with an enamine of the Formula VII where R 4  is a cyano, carboxy, carboxylic ester or amide group, of the tautomeric ketimides thereof, to give bis-azo compounds which are converted to copper complexes, e.g. by reaction with copper sulphate, which on heating yield the bis-[triazolyl-(2)]-stilbenes, the cyano, ester or amide group of which can be hydrolysed to the free acid, and (4) to prepare the unsymmetrical compounds, by reacting a monohydrazino stilbene of the formula or a diazo compound of the monoamine of the formula with a 1,2,4-oxadiazole of the Formula III above, or an α-nitro-ketoxime of the Formula VI above, or an enamine of the Formula VII above and converting the mono-hydrazones or azo compounds so obtained to mono-[triazolyl-(2)]- stilbenes of the formula which are reduced to the amine and converted to values of Y as above, and (5), to prepare unsymmetrical compounds in which Y is hydrogen, halogen or an optionally substituted triazolyl or pyrazolyl, by reacting compounds of the formula as set out in (4) above. The triazolyl-stilbenes exhibit blue-fluorescence and are used as optical brightening agents (see Divisions C3 and D1).