Patent GB-980406-A (GB)
Title: Methine dyes and their preparation
IPC: C07D277/66
Filed: 1963-08-07
Abstract: Intermediates for the production of methine dyes include aldehydes of the general formula <FORM:0980406/C2/1> in which R is alkyl, benzyl, phenethyl, hydroxyethyl, cyanoethyl, chloroethyl, bromoethyl, alkoxymethyl, alkoxyethyl,2-(2-hydroxyethoxy)-ethyl, or an -(alkylene)-SO3M radical; X and Y are hydrogen, alkyl, alkoxy, fluorine chlorine or bromine; the alkylene attached to SO3M is a straight or branched chain of 2-4 carbon atoms; the alkyl and alkoxy groups have 1-4 carbon atoms; M is hydrogen, alkali metal, alkaline-earth metal, or ammonium. The sulpho group may be introduced by reacting the corresponding halogen compound with an alkali metal sulphite.  A large number of aldehydes is given and in specific examples the following are prepared:-p - [ethyl(2 - sulphoethyl) - amino] - benzaldehyde; p - [methyl-(2 - sulphoethyl) - amino] - benzaldehyde; p - [bis(2 - sulphoethyl) - amino] - benzaldehyde; p - [(4 - chlorobutyl)methyl amino] - benzaldehyde. Other intermediates described are compounds obtained by condensing an alkyl cyano acetic ester with an aldehyde of the stated general formula or with an amino-sulphonic acid of one of the following general formulae <FORM:0980406/C2/2> In specific examples, the following compounds are prepared:-the sodium salt of a -cyano-4-[ethyl - (2 - sulphoethyl) - amino] - cinnamic acid; 4 - [bis(2 - chloroethyl) - amino] - a  - cyanocinnamic acid ethyl ester; 4-[bis(2-sulphoethyl) - amino] - a  - cyanocinnamic acid ethyl ester; 6-(cyanoacetamido)-1-naphthol-3-sodium sulphonate; 2 - [p - (cyanoacetamido) - phenyl] - 6 - methyl - 7 - benzothiazole sodium sulphonate; 7 - (cyanoacetamido) - 1 - naphthol - 3 - sodium sulphonate; 4,41 - bis(cyanoacetamido) - 2,21 - stilbene disulphonic acid disodium salt; 2 - [p - (cyanoacetamido) - phenyl] - 6 - methyl - 7 - benzothiazole calcium sulphonate.ALSO:The invention comprises methine dyes of the general formula <FORM:0980406/C4-C5/1> in which ArSO3M is 6 or 7 naphthyl-1-hydroxy-3-sulphonic acid, 2,21-stilbene disulphonic acid, or 2 - phenyl - 6 - methyl - 7 - benzthiazole sulphonic acid, n is 1 or 2, R is alkyl, benzyl, phenethyl, 2-hydroxyethyl, 2-cyanoethyl, 2-chloroethyl, 2-bromoethyl, alkoxymethyl, 2-alkoxyethyl, 2 - (2 - hydroxyethoxy) - ethyl or alkylene-SO3M.  X and Y are hydrogen, alkyl, alkoxy, fluorine, chlorine or bromine, the alkylene group being a straight or branched aliphatic hydrocarbon chain having 2-4 carbon atoms in which the sulphonic acid group is on a carbon atom 2-4, the above alkyl and alkoxy radicals contain 1-4 carbon atoms, M is hydrogen, an alkali or alkaline earth metal or the ammonium radical.  The compounds are obtained by condensing (a) a p-aminobenzaldehyde compound having at least one sulphoalkyl group attached to the nitrogen or a group capable of being converted to same, preferably a haloethyl group, (b) an alkyl cyanoacetate, and (c) an aminoaryl sulphonic acid.  The condensations are done by two methods: I, a-\sYb giving ab, followed by ab-\sYc giving abc, or II b-\sYc giving bc, followed by a-\sYbc giving abc.  When the p-aminobenzaldehyde compound does not contain a sulphonic acid group, this may be introduced at any stage of the above condensation processes by treating with an alkali metal sulphite to replace the halogen in the haloethyl group.ALSO:Paper is dyed in the pulp form with dyes having the general formula <FORM:0980406/D1-D2/1> in which ArSO3M is 6 or 7-naphthyl-1-hydroxy-3 sulphonic acid, 2,21-stilbene-disulphonic acid or 2-phenyl-6 methyl-7-benzthiazole sulphonic acid, n is 1 or 2, R is alkyl, benzyl, phenethyl, 2-hydroxyethyl, 2-cyanoethy, 2-chloroethyl, 2-bromoethyl, alkoxymethyl, 2-alkoxyethyl, 2-(2-hydroxy-ethoxy)-ethyl, 2-cyanoethyl, 2-chloroethyl, 2-bromoethyl, alkyl, alkoxy, fluorine, chlorine or bromine, the alkylene group being a straight or branched aliphatic hydrocarbon chain having 2-4 carbon atoms in which the sulphonic acid group is on a carbon atom 2-4, the above alkyl and alkoxy radicals contain 1-4 carbon atoms, M is hydrogen, or alkali or alkaline ester metal or the ammonium radical.  Examples 21 and 22 give paper dyeing processes.