Abstract: Dyestuff of the formula: ##STR1## in which A represents a mono- or disulphonated naphthalene residue which is unsubstituted or substituted by a hydroxy group and/or by an amino group, B represents an aliphatic, aromatic or heterocyclic residue and D represents the residue of a pyrazolone or an ester or amide of .beta.-ketonic acid; process for the coloration of animal or polyamide fibres in which the coloring agent is a dyestuff of the above formula and articles based on animal or polyamide fibres colored by means of such a dyestuff.

Abstract: The invention relates to a process for the preparation of the dyestuff Direct Yellow 11 directly in the form of stable concentrated solutions, in which caustic soda in aqueous solution is reacted, at a temperature from 40.degree. to 90.degree. C., with a solution containing 4-nitro-toluene-2-sulfonic acid, one or more alkanolamines, one or more alcohols containing an etheroxide function or a second alcohol function, then the caustic soda is neutralized by addition of sulfuric acid and the sodium sulfate thus formed is separated by filtration. The solutions obtained by the process according to the invention are particularly suitable for dyeing cellulosic materials and leather.

Abstract: Dyestuffs of the formula: ##STR1## in which C.sub.2 represents the radical of the formula: ##STR2## where X is NH.sub.2 or OH, C.sub.1 and C.sub.3 are different residues of molecules C.sub.1 H and C.sub.3 H free from azo groups and selected from the group consisting of acetylacetic derivatives, pyrazolonic derivatives, benzenic derivatives, and naphthalenic derivatives, only one of the molecules C.sub.1 H and C.sub.3 H being a naphthalenic derivative, one at least of the residues C.sub.1 and C.sub.3 having at least one and at most two sulphonic acid groups, and n having the value 0 or 1 and leather colored with such dyestuffs.

Abstract: A process for preparing 2-(4'-aminophenyl) 5-amino benzimidazole, a known intermediate used in the synthesis of azo dyes, is disclosed wherein p-nitrobenzoic acid is condensed with aniline, and the N(4'-nitrobenzoyl) aniline produced is dinitrited to N(4'-nitrobenzoyl) 2,4-dinitroaniline; the latter is reduced to the corresponding triamine, which, upon cyclodehydration, results in the 2-(4'-aminophenyl) 5-amino benzimidazole.

Abstract: Dyestuffs of the formula: ##STR1## in which C.sub.2 represents the radical of the formula: ##STR2## where X is NH.sub.2 or OH, C.sub.1 and C.sub.3 are different residues of molecules C.sub.1 H and C.sub.3 H free from azo groups and selected from the group consisting of acetylacetic derivatives, pyrazolonic derivatives, benzenic derivatives, and naphthalenic derivatives, only one of the molecules C.sub.1 H and C.sub.3 H being a naphthalenic derivative, one at least of the residues C.sub.1 and C.sub.3 having at least one and at most two sulphonic acid groups, and n having the value 0 or 1 and leather colored with such dyestuffs.

Abstract: Liquid dyestuffs of the general formula: ##STR1## in which A and B each represent the residue of an aromatic benzene or naphthalene primary amine, possibly substituted by alkyl or alkoxy groups containing 1 to 2 carbon atoms, n represents 0 or 1, y represents 0 or 1, x and Z each represent a whole number such that the sum x + y + z is a whole number from 5 to 17, a process for the preparation of such dyestuffs in which there is coupled in aqueous medium the diazo derivative of an amine of the general formula:A - [N=N - B].sub.n -NH.sub.2in which A, B, n have the same significance as in claim 1, with a compound of the formula: ##STR2## in which x, y and z have the same significance as above, and the use of these dyestuffs for the coloration of petroleum products, inks, fats, waxes and plastics material.

Abstract: Liquid dyestuffs of the general formula: ##STR1## in which y represents 0 or 1, x and z each represent a whole number in which the sum x + y + z is a whole number from 5 to 17; a process for the preparation of such dyestuffs in which the bis-diazo derivative of bis-(4-amino-phenyl)-sulphide is coupled in aqueous medium with a 2-N-alkylamino-naphthalene of the formula: ##STR2## x, y and z having the same significance as above, in the proportion of two molecules of naphthalene derivative to one molecule of bis-diazo derivative; and the use of these dyestuffs for the coloration of petroleum products, inks, fats, waxes and plastics materials.

Abstract: The invention is directed to pentakisazo dyestuffs of the formula: ##SPC1##In which A.sub.1 and A.sub.2 may be the same or different and each is monosulphonaphthylene, hydroxy-monosulpho-naphthylene or hydroxy-disulphonaphthylene and B.sub.1 and B.sub.

Abstract: Azo dyestuffs of the formula: ##SPC1##In which n is zero or 1, R represents a hydrogen atom or an alkyl or aryl group, A.sub.1, A.sub.2 and A.sub.3 each represent the residue of a diazotisable aromatic primary amine, which may be the same or different with at least one of these residues containing at least one sulphonic or carboxylic acid group, and the nucleus B is unsubstituted or substituted by one or two nitro, hydroxy or water-solubilising groups, metalliferous complexes of such dyestuffs and salts of the dyestuffs and of their metalliferous complexes. The dyestuffs of the above formula where n is zero may be prepared by a process which comprises coupling the diazo derivative of a diazotisable aromatic primary amine or the diazo derivatives of two different amines A.sub.1 NH.sub.2 and A.sub.2 NH.sub.2 with a coupling compound of the formula: ##SPC2##In which B and R have the same meaning as in claim 1, at the rate of two molecules of amine to each molecule of coupling compound.