Patent GB-1115614-A (GB)
Title: Bisbenzoxazoles, process for their preparation and their use
IPC: C07D235/20
Filed: 1965-09-01
Abstract: Addition and condensation polymers are optically brightened by addition of a bisbenzoxazolo of the formula <FORM:1115614/C3/1> where R1 and R2 are identical or different and represent hydrogen or halogen or a hydroxyl, nitrile, alkyl, cycloalkyl, alkenyl, phenyl, phenylalkyl, alkoxy, phenoxy, hydroxyalkyl, cyanoalkyl, halogenoalkyl, carboxyalkyl, carbalkoxyalkyl, carboxyl, carbonamide, carboxylic acid ester, sulphonic acid, sulphonic acid ester or a sulphonamide group, and B1 is a direct bond, or a bivalent residue -CH=CH- or <FORM:1115614/C3/2> which residue may be substituted by a nonchoromorphic group, i.e. a group which does group, i.e. a group which does not disturb the fluorescence emission.  The brightening agent may be added before, during or after formation of the polymer, preferably in amounts of 0.001-0.5% by wt. of polymer.  Polyesters, polynamides and polymers based on ethylene, vinyl and acrylic esters and unsaturated halogen compounds are specified.  Examples describe compositions based on (8) polyterephthalic acid ethylene glycol ester granulate, (9) a polyamide derived from hexamethylenediamine adipate, (10) a polyamide derived from e -caprolactam and (11) polypropylene.ALSO:Detergent compositions comprise optical brighteners having the formula <FORM:1115614/C4-C5/1> where R1 and R2 are the same or different and represent hydrogen or halogen or an alkyl, alkenyl, cycloalkyl, phenyl, phenyalkyl, alkoxy, phenoxy, hydroxyalkyl, cyanoalkyl, halogenoalkyl, carboxyalkyl, carbalkoxyalkyl, carboxyl, carbonamide, carboxylic acid ester, sulphonic acid, sulphonic acid ester or sulphonamide group, and R1 is a direct bond or a bivalent residue -CH1=CH- or <FORM:1115614/C4-C5/2> which residue may be substituted by nonchromophoric groups, i.e. those groups which do not disturb the fluorescence emission. Specified detergents are soaps, salts of sulphonate washing agents, and non-ionic detergents.ALSO:The invention comprises bis-benzoxazole derivatives of the formula <FORM:1115614/C2/1> where R1 and R2 are the same or different and represent hydrogen, halogen or a nitrile, hydroxyl, alkyl, cycloalkyl, alkenyl, phenyl, phenylalkyl, alkoxy, phenoxy, hydroxyalkyl, cyanoalkyl, halogenoalkyl, carboxyalkyl, carbalkoxyalkyl, carboxyl, carbonamide, carboxylic acid ester, sulphonic acid, sulphonic acid ester or a sulphonamide group, and B1 represents a direct bond or one of the bivalent residues, -CH=CH- <FORM:1115614/C2/2> <FORM:1115614/C2/3> <FORM:1115614/C2/4> <FORM:1115614/C2/5> <FORM:1115614/C2/6> <FORM:1115614/C2/7> which residues may be substituted by non-chromophoric groups, i.e. those groups which do not disturb the fluorescence emission.  The compounds may be prepared by heating 1 mol of a compound of the formula <FORM:1115614/C2/8> with 2 mols of an hydroxy amine of the formula <FORM:1115614/C2/9> to give the amide <FORM:1115614/C2/100> which cyclizes with loss of water to the benzoxazole. The reaction may be effected without isolation of the intermediate amide, preferably by heating to 120-350 DEG  C. in an inert atmosphere, in the presence of an inert solvent and a catalyst, e.g. boric acid, boric anhydride, ZnCl2, p-toluene sulphonic acid or a phosphoric acid.  The bis-benzoxazoles are used as optical brighteners (see Divisions D1 and C3).  Examples relate to the unsubstituted heterocycles and compounds in which R1 or R2 are, and B1 is substututed by, alkyl groups or halogen atoms.ALSO:Optical brightening agents for fibrous materials comprise bis - benzoxazoles of the formula <FORM:1115614/D1-D2/1> where R1 and R2 are identical or different and represent hydrogen or halogen or a hydroxyl, nitrile, alkyl, cycloalkyl, alkenyl, phenyl, phenylalkyl, alkoxy, phenoxy, hydroxyalkyl, cyanoalkyl, halogenoalkyl, carboxyalkyl, carbalkoxyalkyl, carboxyl, carbonamide, carboxylic acid ester, sulphonic acid, sulphonic acid ester or a sulphonamide group, and B1 is a direct band, or a bivalent residue - CH = CH - or <FORM:1115614/D1-D2/2> which residue may be substituted by a nonchromo-phoric group. The preferred materials are natural or synthetic woven fabrics. Treatment may be effected using an aqueous suspension or solution of the bis - benzoxazole, optionally containing a dispersant impregnating the material at a temperature below 75 DEG C, drying the material at a temperature up to 100 DEG C and subjecting the impregnated material to heat treatment at 120 DEG - 225 DEG C. Example 7 describes the treatment of a polyester fabric.