The invention comprises dyestuffs of formula R-N = N-R1-X, where R is a naphthylamine sulphonic acid residue bound to the azo group in a position vicinal to the amino group, R1 is a benzenic residue and X is a heterocyclic residue having no dyestuff character bound through a nitrogen bridge to R1 and containing a reactive halogen atom and a single heterocyclic ring. Preferred are dyestuffs of formula <FORM:0780591/IV (b)/1> where R is the residue of a 2-naphthylamine mono-sulphonic acid bound to the azo group in the 1-position, R1 is as before and A is an alkyl, aralkyl, cycloalkyl or aryl residue bound through an NH-group to the triazine nucleus and particularly dyestuffs of formula <FORM:0780591/IV (b)/2> where Y is an alkyl, aralkyl or aryl sulphone group or advantageously an N-substituted sulphonamide group and A is as before. The dyestuffs are made by coupling aminonaphthalene sulphonic acids, e.g. 2-naphthylamine-3,6- and -3,7-disulphonic acids, 2-amino-8-naphthol-3,6-disulphonic acid, 2-naphthylamine-3- or -5-oxy-7, -8-oxy-6- and -7-oxy-4-sulphonic acids, 2-naphthylamine-6-, -7- and -8-sulphonic acids, 2-methyl-, -b -oxyethyl- and -phenyl-amino-8-naphthol-6-sulphonic acids, in an acid medium with a diazo compound of an amine of formula H2N-R1-X. Specified compounds corresponding to X are a ,g -dichloroquinoline, 1,4-dichlorophthalazine, methyldichloro- and 2,4-dichloro - pyrimidine, 2,4 - dichloro - quinazoline and 2,4,7-trichloro-quinazoline, trichloroand tribromo-pyrimidine, preferred being 2,4,6-trichloro-1,3,5-triazine or a 2,4-dihalo-1,3,5-triazine containing an -NH2 or an aliphatic, alicyclic, araliphatic or aromatic residue advantageously containing at most 12 carbon atoms bound to the triazine nucleus through an O, S or N bridge. Compounds mentioned from which the groups containing up to 12 carbon atoms are derived are aliphatic or aromatic hydroxy compounds, mercaptans and especially amines, amides, amino-alcohols, aminoacids and urethanes. Specified amines from which the diazo compounds are prepared are the equimolar condensation products of 2,4-dichloroquinazoline and 1,4-diaminobenzene-2-sulphonic acid, 2,5 - diaminobenzene - 1 - sulphonic acid-N-ethylanilide and 2,5-diamino-1,11-diphenylsulphone. Other condensation products may be obtained from 1 mol. of 1,4-diamino-benzene-2 - sulphonic acid, 1,3 - diaminobenzene - 4 - sulphonic acid, 1,3- and 1,4-diaminobenzene, 4,41 - diaminodiphenylamine and -diaminodiphenyl, 4,41 - dimethyl - 3,31 - diaminodiphenylamine, 4,41- and 2,41-diaminodiphenyl ether, 4,41 - dichloro - 2,21 - diaminodiphenyl ether, 4,41- and 2,21-diaminodiphenyl sulphide, 4,41- and 3,31-diamino-diphenyl-sulphone, 2,5-diaminobenzene-1-methyl and -ethyl sulphones, 2,5-diamino-41-methyl- and -methoxy-1,11-diphenyl - sulphone, 2,5 - diamino - 1,11 - diphenyl - sulphone, 2,5 - diaminobenzene - 1 - sulphonamide, 2,5 - diaminobenzene - 1 - sulphonic acid methyl-, ethyl-, phenyl-, p-tolyl-, cyclohexyl-, dimethyl- and diethyl-amides and 2,5-diaminobenzene-1-sulphonic acid N-methyl-and ethyl-anilides and 1 mol. of a condensation product from equimolar quantities of cyanuric chloride and methanol, ethanol, butanol, phenol, o-, m- and p-cresols, 4-sec.-butyl-phenol, 4-tert.-amyl-phenol, dialkyl-phenols, p-chlorophenol, methyl-, dimethyl-, ethyl-, diethyl-, isopropyl-, butyl-, hexyl-, phenyl-, tolyl-, 4-chlorophenyl-, N-methylphenyl- and cyclohexyl-amines, ethanolamines, acetamide, butyramide, urea, thiourea, toluene sulphonamides, glycocoll, methyl and ethyl esters of aminocarbonic acid, ethylaminoacetate, aminoacetamide, 1- and 2-naphthylamine-4- and -6-sulphonic acids, aniline-3-and -4-sulphonic acids and the sulphones or sulphonamides of these acids. The dyestuffs may also be made by condensing, advantageously in the presence of an acid-binding agent and an organic medium, equimolar quantities of a dyestuff of formula R-N=N-R1-Z where R and R1 are as above and Z is an amino group containing at least one reactive hydrogen atom and an appropriate heterocyclic halogen compound, and, if the resulting product contains two exchangeable halogen atoms, exchanging one by condensation with an appropriate compound. The dyestuffs dye animal fibres such as leather, silk and wool, and animalized artificial silk and superpolyamides and superpolyurethanes from a weakly acid, neutral or weakly alkaline dyebath. Examples are provided illustrating the preparation of the dyestuffs from certain of the above reactants and their use in dyeing wool which is coloured red shades, additional compounds specified for condensation with cyanuric chloride are 2- and 3-chloro- and 2- and 4-methoxy- and -methylphenylamines, a further specified compound corresponding to R1 being 2-amino-5-methylamino-41-methyl-diphenylsulphone.ALSO:Dyestuff intermediates of formula H2NR1X are described where R1 is a benzene residue and X is a heterocyclic residue having no dyestuff character bound to R1 through a nitrogen bridge and which contains a reactive halogen atom and a single heterocyclic ring. Preferred are compounds in which the heterocyclic ring is a 1,3,5-triazine, other rings specified being quinoline, phthalazine, quinazoline and pyrimidine. Preferably the triazine nucleus contains an alkyl, aralkyl, cycloalkyl or aryl substituent bound to the ring through an NH group, the two N atoms attached to R1 are in p-position and R1 contains an alkyl, aralkyl or aryl sulphonyl group oto the NH2 group. Advantageously the triazine substituent contains at most 12 carbon atoms and is bound to the triazine nucleus through an O, S or N bridge. The triazine substituent may be derived from ammonia, aliphatic and aromatic hydroxy compounds, mercaptans, amines, amides, amino-alcohols and -acids and urethanes. The compounds are prepared by the condensation, optionally in the presence of acid-binding agents and organic solvents, of appropriate diamines and heterocyclic halides which, in the case of triazines, may contain the required substituent. Alternatively the triazine substituent may be added by condensing the product of the reaction between appropriate diamines and cyanuric halides, with an appropriate compound. Specified condensation products are those made by reacting 2,4-dichloroquinazoline with 1,4-diaminobenzene - 2 - sulphonic acid, 2,5 - diamino - benzene - 1 - sulphonic acid - N - ethylanilide and 2,5 - diamino - 1,11 - diphenylsulphone. Other condensation products may be made from 1,4-diaminobenzene-2- and 1,3-diaminobenzene - 4 - sulphonic acids, 1,3 - and 1,4 - diaminobenzene, 4,41 - diaminodiphenylamine and -diphenyl, 4,41 - dimethyl - 3,31 -diaminodiphenylamine, 4,41- and 2,41-diaminodiphenyl ether, 4,41 - dichloro - 2,21 - diaminodiphenyl ether, 4,41 - and 2,21 - diaminodiphenyl sulphide, 4,41- and 3,31-diaminodiphenylsulphone, 2,5 - diaminobenzene - 1 - methyl and -ethyl sulphones, 2,5-diamino-41-methyl-and -methoxy-1,11-diphenyl sulphone, 2,5 - diamino - 1,11 - diphenylsulphone, 2-amino - 5 - methylamino - 41 - methyldiphenylsulphone, 2,5 - diaminobenzene - 1 - sulphonamide, 2,5 - diaminobenzene - 1 - sulphonic acid methyl-, ethyl-, phenyl-, p-tolyl-, cyclohexyl-, dimethyl- and diethyl-amides and 2,5-diaminobenzene - 1 - sulphonic acid N - methyl- and -ethyl-anilides and the reaction product from equimolar quantities of cyanuric chloride and methanol, ethanol, butanol, phenol, o-, m- and p-cresols, 4-sec.-butylphenol, 4-tert.-amylphenol, dialkyl - phenols, p - chlorophenol, methyl-, dimethyl-, ethyl-, diethyl-, isopropyl-, butyl-, hexyl-, phenyl-, tolyl-, 2-, 3- and 4-chloro- and 2-and 4-methoxy- and -methylphenyl-, N-methylphenyl- and cyclohexylamines, ethanolamines, acetamide, butyramide, urea, thiourea, toluene sulphonamides, glycocoll, methyl and ethyl esters of aminocarbonic acid, ethylaminoacetate, aminoacetamide, 1- and 2-naphthylamine-4- and -6-sulphonic acids, aniline-3- and -4-sulphonic acids and the sulphones and sulphonamides of these acids. The preparation of the dyestuffs from the intermediates is in Group IV (c).