GB993055A - Improvements in or relating to optical whitening agents - Google Patents

Abstract

The invention comprises compounds of the general formula <FORM:0993055/C2/1> in which X is -SO2R where R is an alkylene group containing at least two carbon atoms and which may be interrupted by one or more oxygen atoms, Y is hydrogen, halogen, alkoxy, alkylamino, dialkylamino or an acylamino group. The group R is preferably an hydroxyl group which may be esterified for example by mono or dibasic carboxylic acids, sulphuric acid or phosphoric acid. R is preferably CH2CHOH.R1 where R1 is alkyl or (CH2OCH2)n, n=0 or an integer, e.g. 1-5. X and Y are preferably para orientated. The compounds may be prepared by condensing a compound of general formula XC6H4NHNH2 (II) with a compound of the general formula <FORM:0993055/C2/2> where R2 and R3 are alkyl, e.g. CH3 or C2H5 or together form a heterocyclic ring with the adjacent nitrogen atom. Alternatively, instead of III, there may be used p-YC6H4COCH=CH2 or YC6H4COCH2CH2.Hal where Hal is generall C1 or Br. The stannic chloride complex compound of II may be used. This is prepared from the coresponding primary amine which is diazotized and then reduced in the presence of stannic chloride. The reaction between II and III may be effected by heating the reactants in a solvent medium or reacting in an aqueous alkaline solution. Typical examples describe the preparation of:-(1) 1-[41-(211-hydroxyethylsulphonyl)phenyl] - 3 - (41 -chlorophenyl) pyrazoline from the stannic chloride complex of 4 - (21 - hydroxyethylsulphonyl)-phenyl hydrazine and 3-dimethylamino-4-chloro propiophenone hydrochloride; (2) the product of Example (1) from the uncomplexed hydrazine and propiophenone of Example (1); (3) 1 - [41 - (211 - hydroxyethylsulphonyl)-phenyl] - 3 - [41 chlorophenyl] pyrazoline from 4 (21 - hydroxyethylsulphonyl)phenyl hydrazine sulphate and 3,41-dichloropropiophenone; (4) 1 - [4 - (211 - hydroxy propyl sulphonyl)-phenyl] - 3 - (4 - chlorophenyl) pyrazoline from 4-chlorophenyl vinyl ketone and 4-(21 - hydroxy propyl sulphonyl) phenyl hydrazine; (6) 1-[41-(211-hydroxy ethyl sulphonyl)phenyl]-3-(41 dimethyl amino phenyl) pyrazoline from 3,41 bis (dimethylamino)propiohenone hydrochloride and the stannic chloride complex of 4-(21-hydroxyethyl sulphonyl) phenyl hydrazine. The products may be incorporated in detergent compositions and act as optical whitening agents (see Division D1).ALSO:A composition for treating fabrics comprises an optical whitening agent of general formula <FORM:0993055/D1-D2/1> where X is the group SO2R in which R is an alkylene group containing at least two carbon atoms and which may be interrupted by one or more oxygen atoms, said alkylene group containing at least one group (generally OH or esterified OH or CH2CHOHR1 where R1 = (-CH2OCH2-)n n = 0 or integer e.g. 1-5) and Y is hydrogen, halogen, alkoxy, acylamino, alkylamino, or dialkylamino. The compound may be used in admixture with a detergent of the soap or soapless class, washing agent or other textile auxillary in suitable proportion e.g. 0.01-0.5% preferably 0.01-0.2% by weight. In an example (1) nylon fabric was treated for 30 min at 80 DEG C. in baths containing per litre 0.05-0.5 g of 1[41-(211 hydroxy ethyl sulphonyl) phenyl] -3-(41-chlorophenyl) pyrazoline, the fabric-liquor ratio being 1 : 40. The compound was dissolved in dimethylformamide and diluted with water, containing a small quantity of a non-ionic detergent, to the required volume.