Patent GB-878942-A (GB)
Title: New stilbene brightening agents
IPC: C07D257/04
Filed: 1957-10-04
Abstract: The invention comprises stilbene tetrazoles of the general formula <FORM:0878942/IV (b)/1> wherein R represents hydrogen or an alkyl or aryl radical, X1 and X2 represent, independently of each other, a sulphonic acid, carboxylic acid or sulphonamide group and Y represents an acylamino or carbamido group, a disubstituted triazinylamino group, an arylotriazolyl -(2)-group (which may be substituted by sulphonic acid, carboxylic acid, alkyl or alkoxy groups or by another arylotriazolyl -(2)- group or which may be fused to a 2-substituted triazolyl system) or a tetrazoyl -(1)-group which may be substituted by an alkyl or aryl radical; and salts of these compounds.  These compounds may be prepared, according to one method, by diazotizing an amine of the general formula <FORM:0878942/IV (b)/2> and treating the diazonium product in an alkaline medium with a mono- or diacyl hydrazine such as diformyl-, diacetyl- or benzoyl-hydrazine.  A second method comprises contacting amino stilbene tetrazoles of the general formula <FORM:0878942/IV (b)/3> with agents capable of converting the free amino group into a member of the group as defined above by Y.  Thus, the amino group may be reacted with a carboxylic acid chloride or an appropriate isocyanate or with cyanuric chloride followed be replacement of the remaining chlorine atoms by aliphatic, aromatic or heterocyclic amines; alternatively, the amino group may be diazotised and the diazo product coupled with an aromatic amine capable of coupling in the o-position to the amino group and the resulting o-amino azo compound oxidised, or the diazo product may be coupled with a mono- or di-acyl hydrazine in sodium carbonate solution and then treated with sodium hydroxide solution.  The products may be used as optical brightening agents for natural or synthetic textile materials, detergents, paper, leather and resins (see Groups III and IV(c)).  In Examples: (1) the tris-sodium salt of a 4-(sulpho-naphtho triazolyl)-41- tetrazolyl-stilbene-2,21-disulphonic acid is prepared by diazotising the corresponding 41-amino stilbene-naphtha triazole trisulphonic acid and reacting the product with diformyl hydrazine in aqueous NaOH; (2) the di-sodium salt of 4-naphthotriazolyl-41-tetrazolyl stilbene -2,21-disulphonic acid is prepared by diazotising 4-nitro-41-amino stilbene disulphonic acid, coupling with diformyl hydrazine yielding 4-nitro-41-tetrazolyl-stilbene disulphonic acid, reducing the nitro group to the amino group with iron and acetic acid, diazotising the product and coupling with b -naphthylamine and oxidising the resulting dye stuff with ammoniacal copper sulphate; (3) the tris-sodium salt of another 4-(sulpho naphtho triazoyl)-41-tetrazolyl stilbene-2,21-disulphonic acid is prepared by coupling the diazotised 4-amino-41-tetrazolyl stilbene disulphonic acid of (2) with sodium 2-amino-naphthalene-5-sulphonate and oxidising the resulting dye.  Numerous other stilbene tetrazole products are described including some wherein X1 and X2 represent -SO3Na and either R is hydrogen and Y a methoxy benzamido, phenyl carbamido or 3-anilino-5-hydroxyethyl amino- or 3-anilino-5-morpholino-triazolyl group, or R is phenyl and Y the phenyl tetrazolyl radical; the compounds wherein X1 and X2 represent -COONa, R is hydrogen and Y is the naphtho-triazolyl radical, and the symmetrical benzo bis[4-methyl-tetrazolyl-(1)-2,21-disulpho stilbenyl-41)-triazole] tetra sodium salt.  Amino-stilbene tetrazole starting materials of the above general formula may be prepared from amino stilbenes of the general formula <FORM:0878942/IV (b)/4> wherein Z is an acylamino or nitro group, by diazotising, coupling with a mono- or diacyl hydrazine in sodium carbonate solution, treating the mixture with aqueous NaOH and converting the substituent Z in the resulting stilbene tetrazole into a primary amino group by hydrolysis or reduction.ALSO:Paper, leather and natural and synthetic textile materials such as articles of wool, natural or regenerated cellulose, cellulose acetate, polyesters, polyamides and polyacrylonitriles are optically brightened by treatment with fluorescent stilbene tetrazoles having the general formula:- <FORM:0878942/IV(c)/1> wherein R represents hydrogen or an alkyl or aryl radical, X1 and X2 represent, independently of each other, a sulphonic acid, carboxylic acid or sulphonamide group and Y represents an acylamino or carbamido group, a di-substituted triazinyl amino group, an arylotriazolyl-2 group (wherein the arylo group may be substituted by sulphonic acid, carboxylic acid, alkyl or alkoxy groups or by another arylotriazolyl-(2) group or which may be fused to another 2-substituted-triazolyl group), or a tetrazolyl-1 group which may bear alkyl or aryl substituents, or salts of these compounds.  The brightening agents may be used in aqueous or organic solution or as a dispersion.  In examples:-(1) a white cotton material is rinsed in an aqueous bath containing the trisodium salt of a 4-(sulphonaphthotriazolyl)- 4-tetrazolyl stilbene-2 : 21-disulphonic acid; (2) unbleached cotton material is bleached in a buffered aqueous hypochlorite bath containing the di-sodium salt 4-naphthotriazolyl-41-tetrazolyl stilbene-2 : 21-disulphonic acid; (3) white or yellowish poly-caprolactam fibre is treated with an aqueous bath containing a brightening agent analogous to that used in (1), the bath being acidified with acetic acid.  Numerous other stilbene tetrazoles are mentioned.  o-Amino azo dyestuffs may be prepared as intermediates for the stilbene tetrazoles (see Group IV(b)) by diazotizing an amino stilbene tetrazole of the general formula:-  <FORM:0878942/IV(c)/2> wherein X1, X2 and R are as above defined and coupling the diazo product with an aromatic amine capable of coupling in the o-position to the amino group.  In Examples (2) and (3), 4-amino-41-tetrazolyl-stilbene-2  : 21-disulphonic acid sodium salt is diazotized and coupled with b -naphthylamine or 2-aminonaphthalene-5-sulphonic acid.ALSO:Soaps and other detergents are optically brightened by treatment with fluorescent stilbene tetrazoles having the general formula <FORM:0878942/III/1> wherein R represents hydrogen or an alkyl or aryl radical, X1 and X2 represent, independently of each other, a sulphonic acid, carboxylic acid or sulphonamide group and Y represents an acylamino or carbamido group, a disubstituted triazinylamino group, an arylotriazolyl-(2)-group (which may be substituted by sulphonic acid, carboxylic acid, alkyl or alkoxy groups or by another arylotriazolyl-(2)-group or which may be fused to a 2-substituted triazolyl system), or a tetrazolyl-(1) group which may be alkyl or aryl substituted, and salts of these compounds.