Patent GB-721281-A (GB)
Title: Improvements in or relating to diaminostilbene disulphonic acid derivatives
Filed: 1951-12-17
Abstract: Cellulosic fabrics and pellicles are whitened and brightened by treating them with an aqueous solution of a stilbene derivative as below and drying them.  The brightening agents are those of the formula <FORM:0721281/IV (c)/1> where Alk and R are C1-C4 alkyl groups, r is 0-2, m is an integer so that (r + m) is 1-3, Y is hydrogen or an alkali metal or ammonium ion, and R1 is amino, alkylamino, hydroxyalkylamino, arylamino, hydroxy, alkoxy, alkoxy-alkoxy or aryloxy.  The treatment may be carried out during or after bleaching, the compounds being unaffected by hypochlorites. Specified compounds are those in which R1 is phenoxy or anilino and in which the acyl group on the left-hand side of the formula is 4-methoxybenzoyl, 2 - ethoxybenzoyl, 2 : 4 - di - methoxybenzoyl, 2 - methoxy - 4 - methyl - benzoyl and 2 : 5 - dimethyl - 4 - methoxy - benzoyl.  Other suitable groups are mentioned.  Specification 662,558 is referred to.ALSO:The invention comprises stilbene-triazine derivatives of the formula <FORM:0721281/IV (b)/1> where Alk and R are C1-C4 alkyl groups, r is 0-2, m is an integer so that (r+m) is 1-3, Y is hydrogen or an alkali metal or ammonium ion, and R1 is amino, alkylamino, hydroxyalkylamino, arylamino, hydroxy, alkoxy, alkoxy-alkoxy or aryloxy.  These compounds are made by (1) reacting an acylated 4 : 41-diaminostilbene-2 : 21-disulphonic acid with cyanuric chloride in aqueous solution and treating the product with R1H; (2) as in (1) using the diamino-stilbene-disulphonic acid itself and acylating the final product; (3) condensing 2 mols. of 4 - nitro - 41 - aminostilbene - 2 : 21 - disulphonic acid with cyanuric chloride, treating the product with R1H, reducing the nitro groups to amino and acylating the latter; or (4) acylating 4 - nitro - 41 - aminostilbene - 2 : 21 - disulphonic acid, reducing the nitro group to amino, condensing 2 mols. of the product with cyanuric chloride and treating the product with R1H.  The entire sequence of reactions may be carried out in situ, but when the intermediate <FORM:0721281/IV (b)/2> (or the corresponding compound with the chlorine atom replaced) is obtained this is preferably isolated and acylated under anhydrous conditions.  The final product may be converted into its alkali metal or ammonium salt.  In the examples: (1) 2 mols. of 4-nitro-41-aminostilbene-2 : 21-disulphonic acid are condensed with cyanuric chloride and the product reacted with aniline.  The product (formula given) is salted out and the two nitro groups reduced to amino.  The diamino compound is isolated and treated with p-anisoyl chloride in pyridine; (2) as in (1) using o-ethoxybenzoyl chloride for the acylation; (3) as in (1) acylating with a mixture of 2 : 4-dimethoxybenzoic acid and thionyl chloride; (4) as in (3) using 2-methoxy-4-methylbenzoic acid; (5) 2 mols. of 4-nitro-41-aminostilbene-2 : 21-disulphonic acid are condensed with cyanuric chloride and the product reacted with phenol; reduction is carried out as in (1) and acylation effected with 2 : 4-dimethoxybenzoyl chloride; (6) as in (5) using o-ethoxybenzoyl chloride; (7) as in (5) acylating with p-anisoyl chloride; (8) as in (5) using 2 : 5-dimethyl-4-methoxybenzoyl chloride.  Other alkoxybenzoic acids are specified.  The third chlorine atom in the triazine ring may be reacted with ammonia, aniline, chloraniline, toluidine, anisidine, amylamine, diethylamine, methylaniline, aminopyridine, ethanolamines, water, ethanol, propanol, benzyl alcohol, phenol, chlorophenol, cresol, cyclohexanol and polyglycol ethers. Specification 662,558 is referred to.ALSO:Detergent compositions for whitening and brightening cellulosic fabrics and pellicles comprise a detergent, e.g. soap, and a stilbene derivative of the formula <FORM:0721281/III/1> where Alk and R are C1-C4 alkyl groups, r is O-2, m is an integer so that (r+m) is 1 - 3, Y is hydrogen or an alkali metal or ammonium ion, and R1 is amino, alkylamino, hydroxyalkylamino, arylamino, hydroxy, alkoxy, alkoxyalkoxy or aryloxy.  Specified compounds are those in which R1 is phenoxy or anilino and in which the acyl group on the left hand side of the formula is 4-methoxybenzoyl, 2-ethoxybenzoyl, 2 : 4-dimethoxybenzoyl, 2-methoxy-4-methylbenzoyl and 2 : 5 dimethyl-4-methoxybenzoyl.  Other suitable groups are mentioned. Specification 662,558 is referred to.