Patent GB-632095-A (GB)
Title: Manufacture of new monoazo-dyestuffs
IPC: C09B45/16
Filed: 1947-07-02
Abstract: Dye intermediates free from carboxylic and sulphonic acid groups and of the general formula <FORM:0632095/IV (b)/1> wherein x represents an aryl (e.g. phenyl), substituted aryl (e.g. chloro-, alkyl- or alkoxy-phenyl), aralkyl (e.g. benzyl), alkyl (e.g. methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, isoamyl or tert.-amyl) or cycloalkyl (e.g. cyclohexyl) radical and y represents hydrogen or an alkyl radical, are produced by condensing 2-hydroxynaphthalene - 6 - sulphochloride with a primary or secondary amine in the presence of an acid-binding agent (e.g. sodium carbonate or pyridine) in an aqueous or anhydrous medium.  Specification 3796/14, [Class 2 (iii)], is referred to.ALSO:Monoazo dyestuffs are manufactured by coupling diazotized 4-chloro-2-aminophenol-6-sulphonic acid with a coupling component of the general formula <FORM:0632095/IV (c)/1> which is free from carboxylic and sulphonic acid groups and in which x represents an aryl or substituted aryl, aralkyl, alkyl or cycloalkyl radical and y hydrogen or an alkyl group, especially such compounds in which x is phenyl which may be substituted by halogen, alkyl or alkoxy and y is hydrogen or alkyl, or which x and y are both alkyl radicals, which may be identical or different.  The products can be used for dyeing and printing various fibres, but principally those of animal origin (e.g. wool, silk or leather), and may be converted into complex metal (especially chromium) compounds in substance, in the dye bath or on fibre, e.g. by the single-bath chroming and after-chroming processes.  Examples describe the use of 2-hydroxynaphthalene-6-sulphonic acid anilide as coupling component, and the dyeing of wool violet-blue with the product from a bath containing potassium chromate, ammonium sulphate, Glauber salt and, in later stages, acetic acid.  Other coupling components specified are the o-anisidide, p-phenetidide, N-methylamilide, diethylamide and o-chloranilide of 2-hydroxynaphthalene-6-sulphonic, and it is stated that x may also represent a benzyl, cyclohexyl, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, isoamyl or tert.-amyl radical. Specification 3796/14, [Class 2 (iii)], is referred to.  The Specification as open to inspection under Sect. 91 comprises also the use as diazo components of other o-aminophenolsulphonic acids, which may contain further substituents, preferably incapable of salt formation, e.g. nitro, alkyl or alkoxy groups. It is not essential (though preferable) for the products to contain only one sulphonic acid group and to be free from carboxylic acid groups.  Additional examples describe the production of the dyestuffs 2 - aminophenol - 4 - sulphonic acid-->the diethylamide or anilide of 2 - hydroxynaphthalene - 6 - sulphonic acid, 4 - methyl - 2-aminophenol - 6 - sulphonic acid-->the p-phenetidide or o-anisidide, 4-nitro-2-aminophenol - 6 - sulphonic acid-->the N - methylanilide, and 6 - nitro - 2 - aminophenol - 4-sulphonic acid-->the o-anisidide, anilide or diethylamide, and the after-chromed dyeing of wool with the first of these dyestuffs.  2-Aminophenol - 4 : 6 - disulphonic acid and 6 - chloro - 2 - aminophenol - 4 - sulphonic acid are also specified as diazo components.  This subject-matter does not appear in the Specification as accepted.