Patent GB-792212-A (GB)
Title: Improvements in or relating to water-insoluble monoazo dyestuffs
IPC: C09B29/12
Filed: 1956-02-23
Abstract: 1 - Aminophenyl - 4 - carbamic acid esters, in which the benzene nucleus may be substituted by halogen atoms, nitro or hydroxy groups or alkyl, alkoxy or alkylsulphonyl groups containing 1-4 carbon atoms, are used as diazo components in azo dyes (see Group IV (c)) and may be prepared by reducing the nitro group or hydrolysing the acylamino group of 1-nitro- or -acylamino-phenyl-4-carbamic acid esters.  Specified compounds are 1 - amino - 2 - methylsulphonylphenyl - 4 - carbamic acid ethyl ester and the (31-methoxy)-butyl, phenyl, 21-, 31- or 41-alkylphenyl, 21-, 31- or 41-alkoxyphenyl, benzyl, 21-phenylethyl and 21-morpholinoethyl esters of 1-aminophenyl-4-carbamic acid. 1-Aminophenyl-4-carbamic acid (31-methoxy)-butyl and phenyl esters are prepared by reacting 1-acetylamino-4-aminobenzene with chloroformic acid 3-methoxy)-butyl or phenyl ester, filtering off the 1 - acetylaminophenyl - 4 - carbamic acid (31-methyl)-butyl or phenyl ester and hydrolysing it with hydrochloric acid.  1-Amino-2-methylsulphonylphenyl-4-carbamic acid ethyl ester is prepared by reacting 1 : 4-diamino-2-methylsulphonylbenzene (obtainable by reduction of 1 - amino - 2 - methylsulphonyl - 4 - nitrobenzene) with ethyl chloroformate.ALSO:The invention comprises water-insoluble monoazo dyes of formula <FORM:0792212/IV (b)/1> wherein R is the radical of a hydroxybenzene coupled ortho- or parato the hydroxy group, which may be substituted by halogen atoms, or alkyl, alkoxy, amino or alkyl-, dialkyl- or acyl-amino groups, R1 is an alkyl, cycloalkyl, aralkyl or aryl radical which may be substituted and the nucleus A may be substituted by halogen atoms, alkyl, alkoxy or alkysulphonyl groups containing 1-4 carbon atoms, nitro and hydroxy groups.  The dyestuffs may be prepared by (a) coupling the diazo compound of a 1-aminophenyl-4-carbamic acid ester (see Group IV (b)) with a hydroxybenzene or (b) reacting an aminomonoazo compound of formula <FORM:0792212/IV (b)/2> with a chloroformic acid ester.  If the dyestuff contains a free amino group this may be closed by acylation with an aliphatic carboxylic acid or a derivative thereof, or with a chloroformic acid ester.  The dyestuffs dye cellulose ester fibres (see Group IV (a)) and synthetic polyamide, polyvinyl and polyester fibres in yellow to orange shades.  Some of the dyestuffs may also dye wool and silk and colour lacquer oils and synthetic resins.  The degree of dispersion of the dyes in the dyeing process is improved by grinding the dye with suitable wetting, dispersing or emulsifying agents, preferably in the presence of inorganic salt such as sodium sulphate, or by preparing a dyestuff powder by mixing an aqueous paste of the dyestuff with a dispersing agent and drying.  In examples: (1) the dyes are prepared by coupling (some couplings taking place in the presence of pyridine and calcium hydroxide), the following components being specified: 1-aminophenyl-4-carbamic acid (31-methoxy)-butyl or phenyl or 21-, 31- or 41-alkylphenyl or 21-, 31- or 41-alkoxyphenyl or benzyl or 21-phenylethyl or 21-morpholinoethyl ester and 1-amino-2-methylsulphonylphenyl-4-carbamic acid ethyl ester; 1-hydroxy-3-acetyl-, -trifluoroacetyl-, -mono- or trichloroacetyl-, -hydroxyacetyl-, -butyryl-, isobutyryl-, -crotonyl-, -methoxyacetyl-, -(31-methoxy or -hydroxy)-propionyl-, -(41-methoxy or -hydroxy)-butyryl-, -hexanoyl-, -decanoyl-, dodecanoyl-, -tetradecanoyl-, -hexadecanoyl-, -octadecanoyl-, -phenylacetyl-, -benzoyl-, -hexahydrobenzoyl -, - methylsulphonyl -, [N - (41-methyl) - phenylsulphonyl - N - methyl] -, - ethyl - or - diethyl - aminobenzene and 1-hydroxy-2-or -4-methylbenzene; (2) 21-hydroxy - 51 - methyl - 4 - amino - 1:11 - azobenzene is dissolved in pyridine and reacted with ethyl chloroformate; (3) 1-aminophenyl-4-carbamic acid (31-methoxy)-butyl ester is diazotized and coupled with m-aminophenol and the resultant dyestuff reacted with acetic anhydride to acetylate the amino group.  In a Table dyestuffs of formula <FORM:0792212/IV (b)/3> are described, the following values being given to the various radicals: R1, 3-methoxy-butyl, phenyl, 2-phenoxyethyl, 2-(21-methoxy)-ethoxyethyl, ethyl, methyl, n-butyl, 2-ethoxyethyl, cyclohexyl, 2-hydroxyethyl and allyl; x and y, 2-chloro, 2-methoxy-5-methyl, 2-methylsulphonyl, 2-nitro and 2-hydroxy; R, 2-hydroxy-3 - carboethoxyamino - 5 - methyl - phenyl, 2 - hydroxy - 5 - acetylamino - phenyl, 2 - hydroxy - 4 - acetylamino - 5 - methylphenyl, 2-hydroxy-5-chloro-, -methyl-, -tert.-butyl-, -isoamyl-, -iso-octyl-, -phenyl- or -cyclohexylphenyl, 2:4-dihydroxyphenyl, 2-amino-, -acetylamino-, -propionylamino- or -(41-methyl) - phenylsulphonylamino - 4 - hydroxyphenyl, 3 - acetylamino - 4 - hydroxyphenyl, 4 - hydroxyphenyl and 4 - hydroxy - 5 - acetylamino-, -amino-, -methyl-, -carbomethoxy- or -isonitrosomethyl-phenyl.ALSO:Cellulose esters may be dyed in the mass before spinning using water-insoluble monoazo dyes of formula: <FORM:0792212/IV (a)/1> wherein R is the radical of a hydroxybenzene (coupled ortho- or parato the hydroxy group) which may be substituted by halogen atoms or alkyl, alkoxy, amino or alkyl-, dialkyl- or acylamino groups, R1 is an alkyl, cycloalkyl, aralkyl or aryl radical, which may be substituted, and A may be substituted by halogen atoms, nitro or hydroxy groups and alkyl, alkoxy or alkylsulphonyl groups containing 1-4 carbon atoms.  A preferred group of dyes is specified.  In an example the monoazo dye 1-aminophenyl - 4 - carbamic acid (31 - methoxy)-butyl ester --> 1 - hydroxy - 3 - decanoylaminobenzene is added to an acetone/methanol solution of cellulose acetate, the mixture is stirred until part of the solvent has evaporated and then the dyed mass is spun in the normal way.