Patent GB-498051-A (GB)
Title: Manufacture of dyestuffs
IPC: C09B29/32
Filed: 1937-07-14
Abstract: Azo dyes; azo dyes, forming upon the material; regenerated celluloses, dyeing; printing; pseudo-azimidobenzene derivatives.-Azo dyestuffs are manufactured by coupling, in substance or on the fibre, a diazo compound containing no hydroxy, sulphonic acid or carboxylic acid group with an arylide of acetoacetic acid of the general formula <FORM:0498051/IV/1> where R is a residue of the benzene series, (obtainable by condensing the corresponding amines with ethyl acetoacetate).  The production of the dyes on the fibre may be applied to the colouring of vegetable fibres, regenerated celluloses, silk or wool, e.g. by padding the fibre in alkaline solution with the arylides and developing with a diazo compound, or by using preparations or printing colours containing an alkali salt of one of the arylides and a stabilized diazo compound in the form of a nitrosamine or a diazoamino compound, and developing, e.g. by passage through an acid, or by printing with mixtures of the free diazo components or the corresponding N-nitramines and alkali salts of the arylides and treating with nitrous acid, followed, if desired, by alkali.  The dyes produced in substance are useful as pigments or for colouring lacquers or varnishes.  In examples: (1) o-nitraniline is diazotized and coupled with the product obtained by heating 5-amino-2-phenyl-pseudo-azimidobenzene with ethyl acetoacetate in chlorobenzene in the presence of dimethylaniline; (2) cotton is impregnated with the coupling component of (1), and a greenish-yellow dyeing is developed with diazotized 1-amino-2-methyl-4-nitrobenzene, 1 - amino - 2 - methyl - 4 - chlorobenzene, 1-amino-2-nitro-4-chlorobenzene or 1-amino-2-nitro-4-methylbenzene, or redder shades with diazotized 1-amino-2-nitro-4-methoxybenzene or o-aminoazotoluene.  Other diazo components specified are: aniline, ethers or esters of aminophenols, e.g. o- or p-anisidine or 4-chlor-2-aminodiphenyl ether, monoacylated products from 2 : 5-diaminohydroquinone diethyl or dimethyl ether and benzoyl or phenoxyacetyl chloride, aminoazo compounds, e.g. 4-amino-5-methoxy- or -2 : 5-dimethoxyazobenzene, chlorotoluidines, e.g. 4-chloro-1-methyl-2-aminobenzene, nitranilines, e.g. 4-nitro-2-methoxy-1-aminobenzene, o- or m-chloraniline or a - or b -naphthylamine.  Samples have been furnished under Sect. 2 (5) of cotton yarn dyed by the formation thereon of the following dyestuffs: (I) o-nitraniline --> the condensation product from ethyl acetoacetate and 5 - amino - 2 - (41 - methoxy) - phenyl-pseudo-azimidobenzene (obtainable by oxidizing the azo dyestuff p-anisidine --> m-phenylenediamine); (II) 1-amino-2-nitro-4-methylbenzene --> the same coupling component; (III) 1-amino-2-nitro-4-methoxybenzene --> the same coupling component; (IV) o-nitraniline --> the condensation product from ethyl acetoacetate and 5-amino-2-(41-ethoxy)-phenyl-pseudo-azimidobenzene (obtainable by oxidizing the azo dyestuff p-phenetidine --> m-phenylenediamine); (V) p-nitraniline --> the same coupling component; (VI) 1 - amino - 2 - nitro - 4 - methoxybenzene --> the same coupling component; (VII) o-aminoazotoluene --> the condensation product from 5-amino-6-methyl-2-phenyl-pseudo-azimidobenzene; (VIII) 1-amino-2-nitro-4-chlorobenzene --> the condensation product from ethyl acetoacetate and 5-amino-6-methyl-2-(41-methoxy)-phenyl-pseudo-azimidobenzene (obtainable by oxidizing the azo dyestuff p-anisidine --> 2 : 4-diaminotoluene); (IX) 2 : 5-dichloraniline --> the condensation product from ethyl acetoacetate and 5-amino-6-methoxy-2-(41-methoxy) -phenyl-pseudo-azimidobenzene (obtainable by oxidizing the azo dyestuff p-anisidine --> 1 : 3-diamino-6-methoxybenzene; (X) 4 : 41-dichloro-2-aminodiphenyl ether --> the condensation product from ethyl acetoacetate and 5-amino-6-methoxy - 2 - (41 - methoxy) - phenyl - pseudo - azimidobenzene; (XI) 1-amino-2-nitro-4-chlorobenzene --> the same coupling component; (XII) o-nitraniline --> the same coupling component.  The Specification as open to inspection under Sect. 91 comprises also the manufacture of intermediate products by condensing esters of b -ketocarboxylic acids in general with 5-amino-2-aryl-pseudo-azimidobenzenes, and the manufacture of azo dyes by coupling the products in substance or on the fibre with diazo compounds in general.  Additional starting materials specified for use in the preparation of the intermediates are, on the one hand, benzoylacetic and terephthaloylacetic esters, and, on the other hand, 5-amino - 6 - methyl- and 6-methoxy-2-(41-ethoxy)-phenyl-pseudo-azimidobenzene and 5-amino-2-(11-naphthyl) - pseudo - azimidobenzene. Reference is made to the use of sulphonated diazo components, e.g. sulphanilic acid, whereby wool dyestuffs are obtained, and of o-hydroxylated or o-carboxylated diazo components, which yield products which may be converted in substance or on the fibre into metalliferous dyestuffs. This subject - matter does not appear in the Specification as accepted.