Verwendung neuer Phenyl-1,3,4-oxydiazol-Derivate

1,148,745. Phenyl - 1,3,4 - oxdiazole derivatives. CIBA Ltd. 10 May, 1966 [10 May, 1965], No. 20728/66. Heading C2C. [Also in Division C3] The invention comprises compounds of the formula wherein A, represents a 1,3,4-oxdiazolyl, phenyl, 2-benzoxazolyl or 2-naphthoxazolyl residue and B represents a residue (where A 2 stands for a 2-naphthoxazolyl or 2- benzoxazolyl residue and A 3 for a phenyl, 2- benzoxazolyl or 1,3,4-oxdiazolyl residue), and R represents a hydrogen atom or a monovalent, non-chromophoric substituent from the series: a halogen atom, or an alkyl, phenyl, carboxyl, sulpho, hydroxyl or amino group and substitutive or functional derivatives of the foregoing groups, and where terminal phenyl nuclei in the residue A 1 , A 2 or A 3 in the above formulµ may contain 1 or 2 substituents R and/or the phenylene nuclei of the formulµ may contain one such substituent R. Examples of substitutive and functional derivatives of the foregoing groups include halo-, hydroxy-, carboxy-, amino and phenyl-alkyl groups, alkyl-, halo-, alkoxy- and carboxyhydrazide groups and the analogous sulphonic acid derivatives; alkoxy, aralkoxy, phenoxy and hydroxy-alkoxy groups and amino groups which are alkylated, arylated or acylated. The compounds of the invention are obtained by reacting appropriate carboxylic acid halides with appropriate carboxylic hydrazides and cyclizing the products, e.g. by dropping in thionyl chloride at elevated temperature. The products may be converted to water soluble derivatives, e.g. by sulphonation or quaternation. Many specific products are described. Hydrazides employed as starting materials are prepared by reacting corresponding methyl or ethyl carboxylates with hydrazine hydrate. Carboxylic acid chlorides employed as starting materials are obtained by reacting corresponding carboxylic acids with thionyl chloride. The phenyl-1,3,4-oxidiazole derivatives are employed as optical brighteners (see Division C3).