Patent GB-606814-A (GB)
Title: Manufacture of new ester-like derivatives of azo-dyestuffs
IPC: C09B43/18
Filed: 1945-10-05
Abstract: Ester-like derivatives of dyestuffs are manufactured by subjecting a monazo dyestuff, obtained by coupling a diazotized o-hydroxy aromatic amine with a coupling component which couples in a position vicinal to a hydroxy group or an enolized keto group (the components being so selected that the resulting dyestuff shall be free from substituents imparting solubility in water, and, if it contains no nitro-groups, shall contain at least two halogen atoms) to treatment in the presence of a tertiary base (e.g. pyridine or thiazole) with an organic acylating agent containing, in addition to the acylating group, at least one substituent capable of forming a salt.  The reaction mixture may be worked up by distilling-off the tertiary base under reduced pressure and precipitating the esterification product by pouring the residue into a salt solution, or by converting the esterification product into a sparingly soluble double salt by adding to the original reaction mixture suitable metal chlorides, e.g. zinc chloride, or inorganic or organic acids.  The products may be used for dyeing animal fibres by the metachrome process according to Specification 601,347.  The following components are specified and examples given of the use of appropriate combinations thereof; diazo components: o-aminophenols such as 1-hydroxy-2-aminobenzene and its -4-chloro-, 4- and 5-nitro-, 4 : 6-dinitro-, 4 : 6-dichloro-, 3 : 4 : 6-trichloro-, 3 : 4 : 5 : 6-tetrachloro-, 4-chloro-5-(and -6-)nitro, 4-nitro-6-chloro-, 4-trifluoromethyl- and 4-methoxy-derivatives, and o-aminonaphthols such as 2 : 1 or 1 : 2-aminonaphthol; coupling components: 1-naphthol and its 4- and 5-chloro-, 5 : 8-dichloro-, 4-methoxy-, 4-ethyl- and 5-nitro-derivatives and its 4-methyl and -phenyl ketones, 2-naphthol and its 6- and 7-methoxy-, 4 : 6-dichloro-, 4 : 6-dibromo- and 5- and 6-nitro-derivatives, 2 : 3-hydroxynaphthoic acid arylides such as the anilide and o-anisidide, compounds of the benzene series such as 4-methylphenol and its allyl-n- and isopropyl-, benzyl- and -ethyl-derivatives, 2-methylphenol and its 4-ethyl-, -isopropyl-, -cyclohexyl- and -benzyl-derivatives and 4-n-propyl-2-benzylphenol, and compounds containing enolizable keto-groups such as 3-methyl-5-pyrazolone and its 1-phenyl- and 1-(31-chloro-, 21 : 51-dichloro- and 31-nitrophenyl)-derivatives, 2 : 4-dihydroxyquinoline and acetoacetic acid anilide, o-anisidide and 2 : 4-dichloranilide; esterifying agents: benzoyl chloride-3-sulphonic acid, the dichloride of m-sulphobenzoic acid, benzoic acid 3 : 5-disulphochloride, 5-sulphosalicylic acid dichloride and sulphoacetic acid chloride. Specifications 480,358 and 482,184 also are referred to.  The Specification as open to inspection under Sect. 91 comprises also the use of acylating agents containing substituents imparting solubility after "suitable conversion" and of 4-chloromethylbenzoyl chloride; the treatment of dihydroxyazo dyestuffs containing at least two substituents not imparting solubility other than a plurality of halogen atoms (e.g. the dyestuffs 4-chloro-2-aminophenol-->p-cresol or 4-methoxy-1-naphthol), or containing an additional azo group (e.g. dyestuffs derived from 41-chloro-4-amino-2-methyl-5-hydroxy-1 : 11-azobenzene as diazo component or from 4-(21 : 31-hydroxynaphthoil)-amino-1 : 11-azobenzene as coupling component), and of dyestuffs derived from 1 : 8-aminonaphthol as diazo component; and the use of the products for dyeing (e.g. of wool in the presence of ammonium sulphate, Glauber salt and sodium chromate, or in the presence of acetic acid, Glauber salt and, in the later stages, sulphuric acid with after-treatment with potassium bichromate in the same bath). This subject-matter does not appear in the Specification as accepted.