Abstract: A dyeing process has been found which enables to dye uniformly polyacrylonitrile fiber materials, by using as dyestuffs basic azo dyestuffs being non-quarternized and containing neither cationic quaternary ammonium groups nor cationic N-substituted or N-unsubstituted iminium groups, said azo dyestuffs containing on the other hand at least one unsubstituted or substituted amino group, hydrazino group, amidino group or guanidino group capable of forming salts. The very dyeing process as such is carried out according to usual processing data for dyeing polyacrylonitriles in a slightly acid medium. Especially with the use of several of these dyestuffs for polychromic dyeing, such as trichromic dyeing, special advantages are obtained, insofar that even at cut-rate dyeing periods and for preparing light color shades, there are obtained even dyes with constant color shades, when using these dyestuffs having good migrating properties.

Abstract: New basic azo dyestuffs of the formula ##STR1## where D.sup.(+) is the radical of an aromatic or heterocyclic diazo component containing a quaternary nitrogen atom,A is an aromatic radical or, together with the -(NR)-member of the formula, forms a heterocyclic radical,R is hydrogen, optionally substituted lower alkyl, aralkyl or cycloalkyl,X.sup.(-) is an anion, andZ is hydrogen or methyl,Had been found which are suitable for dyeing and forming, for example, tannin-treated cellulose fibers, silk, leather, acetate silk, acid modified polyamide or polyester fibers and for dyeing and printing and spin-dyeing of polyacrylonitrile or polyvinylidene cyanide containing fibers. The dyeings and prints obtained are generally are of high tinctorial strength and brilliant and have very good fastnesses.

Abstract: An improved process for isolating 2-hydroxynaphthalenecarboxylic acids from reaction mixtures of the alkali metal salts of the 2-hydroxynaphthalene with carbon dioxide had been found which comprises diluting with water the reaction mixture which contains the di-alkali metal salt of 2-hydroxynaphthalenecarboxylic acid and 2-hydroxynaphthalene, while keeping the mixture at a temperature of at least 80.degree. C, then adjusting the pH-value to about 6 to 7 by means of aqueous mineral acid, separating the lower phase at at least 80.degree. C, cooling the upper phase to about 15.degree. to 25.degree. C, separating the 2-hydroxynaphthalene, then adjusting the pH-value to about 1 to 2 by means of aqueous mineral acid and isolating the separated 2-hydroxynaphthalenecarboxylic acid.

Abstract: New valuable basic oxazine dyestuffs of the formula ##STR1## in which R is hydrogen or lower alkyl, R.sub.1 is hydrogen or lower alkyl substituted by halogen, lower alkoxy, cyano or hydroxy, R.sub.2 and R.sub.3 each is hydrogen or lower alkyl or lower alkyl substituted by halogen, lower alkoxy, cyano or hydroxy, or R.sub.1 and R.sub.2 form together with the nitrogen atom the pyrrolidino, piperazino, piperidino or morpholino ring, and the phenyl nucleus a is substituted by lower alkyl, lower alkoxy, acetyl, cyano, halogen, phenoxy or trifluoromethyl, and X.sup.(.sup.-) is an anion has been found which are well suitable for the dyeing or printing of tanned cellulose fibers, silk, leather, or acetate rayon, synthetic polyamide fibers or acid-modified polyester and polyamide fibers and fibers containing polyacrylonitrile or polyvinylidene cyanide. The dyeings and prints obtained are bright and color-intensive and have good fastnesses to light and to wet processing.