Abstract: Azo dyestuffs free of sulphonic acid groups and carboxylic acid groups are prepared by coupling a diazo compound with a coupler which is prepared by reacting an organic amine with a pyridinium salt having the formula ##STR1## IN WHICH R is substituted or unsubstituted alkyl, cycloalkyl, aralkyl or aryl; andR.sub.1 is substituted or unsubstituted alkyl or aralkyl. The dyestuffs are suitable for dyeing and printing synthetic materials such as polyolefines, polyvinyl compounds, cellulose acetate and triacetate and polyesters to give yellow to blue dyeings and prints with good fastness properties especially to light and sublimation.

Abstract: Disazo dyestuffs of formula ##STR1## in which A represents an alkylene radical with 2 - 5 C atoms,R.sub.1, r.sub.2, r.sub.3 and R.sub.5 represent hydrogen, chlorine, bromine, an alkoxy group or an alkyl group,R.sub.4 represents hydrogen, chlorine, bromine, alkyl, alkoxy or acylamino,R.sub.6 represents an alkyl group,R.sub.7 represents hydrogen or an alkyl group,B represents a 1,4-phenylene or 1,4-naphthylene radical andm represents the numbers 1 - 4,And their use for the dyeing of nitrogen-containing materials, such as wool and silk, but preferably for dyeing synthetic polyamide and polyurethane fibres. Dyeings obtained are characterized by good to very good general fastness properties.

Abstract: Azo dyestuffs of the formula ##STR1## in which D represents the radical of a diazo component,R denotes alkyl, cycloalkyl, aralkyl or aryl,X represents a nitrile group or an optional substituted carbonamide or carboxylic acid ester group,A represents oxygenWhereinR.sub.1 -r.sub.4 denote hydrogen, alkyl or aralkyl as well as their preparation and use for dyeing of synthetic materials are disclosed. For example, polyolefines, polyvinyl polymers, cellulose 2 1/2 acetate, cellulose triacetate and particularly polyesters are dyed by customary dyeing and printing proceses to give yellow to blue dyeings and prints with good fastness properties especially fastness to light and sublimation.

Abstract: Preparation of azo dyestuffs which possess at least one nitrile group in the ortho-position to the azo bridge, by reacting the corresponding ortho-halogenoazo compounds with CuCN or systems which for CuCN, in the presence of nitrogen bases and optionally of surface-active agents, in an aqueous medium, with replacement of at least one halogen substituent, which is in the orthoposition to the azo bridge, by a nitrile group. Preferably the reaction is carried out as one-pot-process. The dyestuffs prepared by the process, a substantial number of which are known, are useful in dyeing natural and synthetic fiber materials.

Abstract: Disazo dyestuffs which in form of the free acid correspond to the formula ##SPC1##Wherein A is an alkylene of 2-5 carbon atoms; R.sub.1, R.sub.2, and R.sub.3 are hydrogen, chloro, bromo, alkoxy, or alkyl; R.sub.4 is alkyl, phenyl, or substituted phenyl; R.sub.5 is hydrogen, alkyl, or alkyl substituted by cyano, carbonamido, or carboxyl; R.sub.6 is a substituent; B is 1,4-phenylene or 1,4-naphthylene; m is a number from 1 to 4; and n is a number from 0 to 2. These dyestuffs are useful for dyeing or printing natural or snythetic fibers containing amide groups, such as wool, silk or polyamide; and the resulting product is distinguished by good fastness properties.