The invention is directed to new benzoxazole-styryls of the formula ##STR1## wherein the rings A, B, C and D can be substituted, as well as processes for their preparation. The invention relates also to a process for optically brightening high-molecular organic materials on using said compounds.

The present invention relates to new benzoxazole-styryls, processes for 
their manufacture and their use for the optical brightening of 
high-molecular organic materials. 
The new benzoxazole-styryls correspond to the formula 
##STR2## 
wherein the rings A, B, C and D can carry non-chromophoric substituents. 
Within the scope of the formula (1), compounds which are of interest are, 
above all, those of the formula 
##STR3## 
wherein R.sub.1 denotes hydrogen, unsubstituted alkyl with 1 to 4 carbon 
atoms, alkyl, with 1 to 3 carbon atoms, which is substituted at the 
terminal carbon atom by a cyano group or COOR group, wherein R represents 
hydrogen, a salt-forming cation or alkyl with 1 to 5 carbon atoms, 
cyclohexyl, phenylalkyl with 1 to 3 carbon atoms in the alkyl part, phenyl 
which is optionally substituted by 1 or 2 substituents from the series 
chlorine, methyl or methoxy; alkoxy with 1 to 4 carbon atoms, phenoxy 
which is optionally substituted by 1 or 2 substituents from the series 
chlorine, methyl or methoxy; chlorine, bromine, cyano, COOR, wherein R 
represents hydrogen, a salt-forming cation, alkyl with 1 to 5 carbon atoms 
or benzyl, CONR' (R.sub.1 '), wherein R' represents hydrogen, alkyl with 1 
to 6 carbon atoms, alkyl, with 2 to 4 carbon atoms, which is substituted 
at the terminal carbon atom by a dialkylamino group or an optionally 
quaternised dialkylamino group with 1 to 4 carbon atoms in each alkyl 
part, hydroxyalkyl with 1 to 4 carbon atoms, alkoxyalkyl with 2 to 8 
carbon atoms, phenyl or benzyl and R.sub.1 ' represents hydrogen, alkyl 
with 1 to 6 carbon atoms, hydroxyalkyl with 1 to 4 carbon atoms or 
alkoxyalkyl with 2 to 8 carbon atoms, or R' and R.sub.1 ', conjointly with 
the nitrogen, represent a morpholino or piperidino radical; SO.sub.2 OY, 
wherein Y denotes hydrogen, a salt-forming cation, alkyl with 1 to 5 
carbon atoms, phenyl or alkyl-substituted phenyl, SO.sub.2 NR' (R.sub.1 
'), wherein R' and R.sub.1 ' have the meaning indicated above, 
alkylsulphonyl with 1 to 6 carbon atoms, benzylsulphonyl, phenylsulphonyl 
or phenylsulphonyl which is substituted by chlorine or methyl, or R.sub.1, 
conjointly with R.sub.2, denotes a fused phenyl ring, R.sub.2 denotes 
hydrogen, alkyl with 1 to 5 carbon atoms, alkoxy with 1 to 4 carbon atoms 
or chlorine or, conjointly with R.sub.1, a fused phenyl ring, R.sub.3 
denotes hydrogen or methyl, X.sub.1 denotes hydrogen, alkyl with 1 to 4 
carbon atoms, cyclohexyl, phenylalkyl with 1 to carbon atoms in the alkyl 
part, phenyl, alkoxy with 1 to 4 carbon atoms, phenoxy, chlorine, cyano, 
COOR, CONR' (R.sub.1 '), SO.sub.2 OY, SO.sub.2 NR' (R.sub.1 '), wherein Y, 
R, R' and R.sub.1 ' each have the abovementioned meaning, alkylsulphonyl 
with 1 to 6 carbon atoms, benzylsulphonyl, phenylsulphonyl or 
phenylsulphonyl which is optionally substituted by chlorine or methyl, 
X.sub.2 denotes hydrogen, chlorine, methyl or methoxy and Z denotes 
hydrogen, chlorine or phenyl. 
Of particular practical interest are the benzoxazole-styryls of the formula 
##STR4## 
wherein R.sub.4 denotes hydrogen, chlorine, unsubstituted alkyl with 1 to 
4 carbon atoms, alkyl, with 2 to 3 carbon atoms, which is substituted at 
the terminal carbon atom by a cyano group or COOR group, wherein R 
represents hydrogen, a salt-forming cation or alkyl with 1 to 5 carbon 
atoms, cyclohexyl, phenylalkyl with 1 to 3 carbon atoms in the alkyl part, 
phenyl or alkoxy with 1 to 4 carbon atoms, R.sub.5 denotes hydrogen or 
alkyl with 1 to 4 carbon atoms, X.sub.3 denotes hydrogen, alkyl with 1 to 
4 carbon atoms, alkoxy with 1 to 4 carbon atoms, chlorine, carbalkoxy with 
2 to 5 carbon atoms, sulphamoyl or sulphamoyl which is monosubstituted or 
disubstituted by alkyl with 1 to 4 carbon atoms or hydroxyalkyl with 2 to 
4 carbon atoms, or alkylsulphonyl with 1 to 4 carbon atoms and Z denotes 
hydrogen, chlorine or phenyl. 
Compounds to be singled out are those of the formula 
##STR5## 
wherein R.sub.4 ' denotes hydrogen, chlorine, unsubstituted alkyl with 1 
to 4 carbon atoms, alkyl, with 2 to 3 carbon atoms, which is substituted 
at the terminal carbon atom by a cyano group or COOR group, wherein R 
represents hydrogen, sodium, potassium or alkyl with 1 to 5 carbon atoms, 
cyclohexyl, phenyl, alkoxy with 1 to 4 carbon atoms or alkylsulphonyl with 
1 to 4 carbon atoms, R.sub.5 denotes hydrogen or alkyl with 1 to 4 carbon 
atoms and Z denotes hydrogen, chlorine or phenyl. 
The compounds of the formula 
##STR6## 
wherein R.sub.6 denotes hydrogen, chlorine, alkyl with 1 to 4 carbon 
atoms, .beta.-cyanoethyl, cyclohexyl, phenyl or alkoxy with 1 to 4 carbon 
atoms and Z denotes hydrogen, chlorine or phenyl, and of the formula 
##STR7## 
wherein X.sub.3 denotes hydrogen, alkyl with 1 to 4 carbon atoms, alkoxy 
with 1 to 4 carbon atoms, chlorine, carbalkoxy with 2 to 5 carbon atoms, 
sulphamoyl which is optionally monosubstituted or disubstituted by alkyl 
with 1 to 4 carbon atoms or hydroxyalkyl with 2 to 4 carbon atoms, or 
alkylsulphonyl with 1 to 4 carbon atoms, also deserve particular mention. 
The compound of the formula 
##STR8## 
proves to be particularly valuable. 
Possible salt-forming cations (symbols R and Y) are, inter alia, alkali 
metal ions or alkaline earth metal ions, ammonium ions which are 
optionally substituted by alkyl or hydroxyalkyl and amine salt ions of 
cyclic amines, such as, for example, pyridine, morpholine or piperidine. 
Sodium ions and potassium ions are preferred here. 
R.sub.1 in the formula (2), R.sub.4 in the formulae (3) and (4) and R.sub.6 
in the formula (5) are preferably in the 5-position of the benzoxazole 
radical, whilst the p-position to the bond to the triazole radical is 
preferred for X.sub.1 in the formula (2) or for X.sub.3 in the formulae 
(3) and (6). Z preferably denotes hydrogen in the preceding formulae. 
The new benzoxazole-styryls of the formula (1) can be manufactured 
according to various processes. 
A large proportion of the new compounds can be manufactured according to a 
new process which is characterised in that a methyl compound of the 
formula 
##STR9## 
is reacted with a Schiff's base of the formula 
##STR10## 
wherein Ar denotes an aromatic radical, in dimethylformamide as the 
reaction medium and in the presence of a strongly basic alkali metal 
compound, it being possible for the reaction mixture to be initially 
irradiated with ultraviolet light. 
The irradiation with ultraviolet light is effected by a source applied 
either outside or inside the reaction vessel. The irradiation with 
ultraviolet light can be used for starting the reaction, and not for 
complete reaction of the reactants. Thus an irradiation time of a few 
minutes is mostly sufficient. Ultraviolet light with a wavelength of over 
300 nm is preferably used. 
The symbol Ar generally represents an optionally substituted naphthyl or, 
in particular, phenyl radical. Ar preferably represents the radical of the 
formula 
##STR11## 
wherein h denotes hydrogen or chlorine. 
In general, a compound of the formula 
EQU MOC.sub.n-1 H.sub.2n-1 ( 10) 
wherein M denotes potassium or sodium and n denotes an integer from 1 to 6, 
is used as the strongly basic alkali metal compound. 
Examples of compounds of the formula (10) which may be mentioned are sodium 
methylate, potassium tertiary-butylate, sodium hydroxide and potassium 
hydroxide. 
In the case of alcoholates, the reaction should be carried out in a 
virtually anhydrous medium, whilst in the case of hydroxides contents of 
water of up to 25% are allowed. 
In the case of potassium hydroxide, which is preferably to be used, a water 
content of up to about 15% has proved appropriate. 
The compound containing the methyl group is appropriately reacted with the 
Schiff's base in equivalent amounts, so that no substantial excess of 
either component is present. At least the equivalent amount of the alkali 
metal compound is advantageously used, that is to say at least 1 mol of 
alkali metal compound per mol of Schiff's base. When potassium hydroxide 
is used preferably two times to eight times the equivalent amount is 
employed. 
The reaction according to the invention can generally be carried out at 
temperatures in the range between about 10 and 40.degree. C. If potassium 
hydroxide is used in the reaction the reaction generally already takes 
place at room temperature, in which case no external supply of heat is 
required. 
If other alkali metal compounds are used, the reaction is to be carried out 
at elevated temperatures, depending on their basic strength. A reaction 
temperature as low as possible is, however, desirable, since side 
reactions, such as, for example, ring cleavage, can occur at higher 
temperatures. 
The end products can be worked up from the reaction mixture according to 
customary methods which are in themselves known. 
A large proportion of the compounds of the formula (1) and, for example, 
those of the formula 
##STR12## 
wherein R.sub.2, R.sub.3, R.sub.4, R.sub.5 and Z have the meaning 
indicated above and R.sub.7 denotes hydrogen, unsubstituted alkyl with 1 
to 4 carbon atoms, alkyl, with 1 to 3 carbon atoms, which is substituted 
at the terminal carbon atom by a cyano group or COOR group, wherein R 
represents hydrogen, a salt-forming cation or alkyl with 1 to 5 carbon 
atoms, cyclohexyl, phenylalkyl with 1 to 3 carbon atoms in the alkyl part, 
phenyl which is optionally substituted by 1 or 2 substituents from the 
series chlorine, methyl or methoxy; alkoxy with 1 to 4 carbon atoms, 
phenoxy which is optionally substituted by 1 or 2 substituents from the 
series chlorine, methyl or methoxy; chlorine, bromine, cyano, COOR, 
wherein R represents hydrogen, a salt-forming cation, alkyl with 1 to 5 
carbon atoms or benzyl, CONR' (R.sub.1 '), wherein R' represents hydrogen, 
alkyl with 1 to 6 carbon atoms, alkyl, with 2 to 4 carbon atoms, which is 
substituted at the terminal carbon atom by a dialkylamino group or an 
optionally quaternised dialkylamino group with 1 to 4 carbon atoms in each 
alkyl part, hydroxyalkyl with 1 to 4 carbon atoms, alkoxyalkyl with 2 to 8 
carbon atoms, phenyl or benzyl and R.sub.1 ' represents hydrogen, alkyl 
with 1 to 6 carbon atoms, hydroxyalkyl with 1 to 4 carbon atoms or 
alkoxyalkyl with 2 to 8 carbon atoms, or R' and R.sub.1 ', conjointly with 
the nitrogen, represent a morpholino or piperidino radical, SO.sub.2 NR' 
(R.sub.1 '), wherein R' and R.sub.1 ' have the meaning indicated above, 
phenylsulphonyl or phenylsulphonyl which is substituted by chlorine, or 
R.sub.7, conjointly with R.sub.2, denotes a fused phenyl ring, X.sub.1 ' 
denotes hydrogen, alkyl with 1 to 4 carbon atoms, cyclohexyl, phenylalkyl 
with 1 to 3 carbon atoms in the alkyl part, phenyl, alkoxy with 1 to 4 
carbon atoms, phenoxy, chlorine, unsubstituted phenylsulphonyl or 
phenylsulphonyl which is substituted by chlorine, X.sub.2 ' denotes 
hydrogen, chlorine, methyl or methoxy and X.sub.3 ' denotes hydrogen, 
alkyl with 1 to 4 carbon atoms, alkoxy with 1 to 4 carbon atoms, chlorine, 
carbalkoxy with 2 to 5 carbon atoms or sulphamoyl which is optionally 
monosubstituted or disubstituted by alkyl or hydroxyalkyl with 2 to 4 
carbon atoms, are obtained in an analogous manner, by reacting a methyl 
compound of the formula 
##STR13## 
with a Schiff's base of the formula 
##STR14## 
wherein X.sub.1 ', X.sub.2 ', X.sub.3 ', R.sub.2, R.sub.3, R.sub.4, 
R.sub.5, R.sub.7, Z and Ar have the meaning indicated above. 
The starting materials of the formulae (7), (8) and (13) to (16) are 
obtained analogously to processes which are in themselves known. 
The compounds of the formulae (1) to (6a) can also be manufactured by 
reacting a methyl compound of the formulae (7), (13) or (14) with an 
aldehyde of the formula 
##STR15## 
wherein the rings B, C and D and the substituents X.sub.1, X.sub.2, 
X.sub.3 and Z have the meaning indicated above, in the presence of a 
catalyst which splits off water or in an inert, high-boiling solvent and 
in the presence of a catalyst, with the simultaneous removal of the water 
of reaction. 
Possible catalysts which split off water are, for example, zinc chloride or 
acetic anhydride. Hydrocarbons and halogenated hydrocarbons such as, for 
example, xylene or chlorobenzene, can be used as inert, high-boiling 
solvents and, for example, p-toluenesulphonic acid together with 
dialkylformamide or dialkylacetamide, preferably dimethylformamide, can be 
used as catalysts for the condensation in the inert solvent. 
Another process, which is in itself known, for the manufacture of most of 
the new compounds of the formula (1) consists in reacting a compound of 
the formula 
##STR16## 
with a compound of the formula 
##STR17## 
wherein the symbol A.sub.1 denotes a grouping of the formula 
##STR18## 
wherein D.sub.1 represents an optionally further substituted alkyl 
radical, preferably an alkyl radical with up to 6 carbon atoms, an aryl 
radical, preferably a phenyl radical, a cycloalkyl radical, preferably a 
cyclohexyl radical, or an aralkyl radical, preferably a benzyl radical, 
and A.sub.2 is a formyl group. 
This manufacturing process is advantageously carried out in inert solvents. 
Examples of these which may be mentioned are hydrocarbons, such as toluene 
and xylene, or alcohols, such as methanol, ethanol, isopropanol, butanol, 
glycols, glycol ethers, such as 2-methoxyethanol, hexanols, cyclohexanol 
and cyclooctanol, and also ethers, such as diisopropyl ether, 
tetrahydrofurane and dioxane, as well as dimethylsulphoxide, formamide and 
N-methylpyrrolidone. Polar organic solvents, such as dimethylformamide and 
dimethylsulphoxide, are particularly suitable. Some of the reactions can 
also be carried out in aqueous solution. 
The temperature at which the reaction is carried out can vary within wide 
limits. It is determined (.alpha.) by the resistance of the solvent used 
to the strongly basic alkali metal compounds, (.beta.) by the reactivity 
of the condensation partners and (.gamma.) by the effectiveness of the 
solvent/base combination as a condensation agent. 
In practice, accordingly, temperatures between 10.degree. and 100.degree. C 
are generally possible, in particular if dimethylformamide or 
dimethylsulphoxide is used as the solvent. The preferred temperature range 
is 20.degree. to 60.degree. C. 
Possible strongly basic alkali metal compounds which can be used are, above 
all, the hydroxides, amides and alcoholates (preferably those of primary 
alcohols containing 1 to 4 carbon atoms) of the alkali metals, those of 
lithium, sodium and potassium being of predominant interest for economical 
reasons. However, in principle and in particular cases, alkali metal 
sulphides and carbonates, aryl-alkali metal compounds, such as, for 
example, phenyl-lithium, or strongly basic amines (including ammonium 
bases), for example trialkylammonium hydroxides, can also be used 
successfully. 
The compounds of the formulae (2) to (6a) are manufactured in an equally 
corresponding manner, for example by reacting a compound of the formula 
##STR19## 
with a compound of the formula 
##STR20## 
wherein R.sub.1 to R.sub.4, X.sub.1 to X.sub.3, Z, A.sub.1 and A.sub.2 
have the meanings indicated above. 
The starting materials of the formulae (20) and (21) and (26) to (29) are 
known or are obtained analogously to processes which are in themselves 
known. 
The new compounds defined above exhibit a more or less pronounced 
fluorescence in the dissolved or finely dispersed state. They can be used 
for optically brightening the most diverse synthetic, semi-synthetic or 
natural organic materials or substances which contain such organic 
materials. 
The following groups of organic materials, where optical brightening 
thereof is relevant, may be mentioned as examples of the above, without 
the survey given below being intended to express any restriction thereto: 
I. Synthetic organic high-molecular materials 
a. Polymerisation products based on organic compounds containing at least 
one polymerisable carbon-carbon double bond, that is to say their 
homopolymers or copolymers as well as their after-treatment products such 
as, for example, cross-linking, grafting or degradation products, polymer 
blends or products obtained by modification of reactive groups, for 
example polymers based on .alpha.,.beta.-unsaturated carboxylic acids or 
derivatives of such carboxylic acids, especially on acrylic compounds 
(such as, for example, acrylic esters, acrylic acid, acrylonitrile, 
acrylamides and their derivatives or their methacrylic analogues), on 
olefine hydrocarbons (such as, for example, ethylene, propylene, styrenes 
or dienes and also so-called ABS polymers), and polymers based on vinyl 
and vinylidene compounds (such as, for example, vinyl chloride, vinyl 
alcohol and vinylidene chloride), 
b. Polymerisation products such as are obtainable by ring opening, for 
example polyamides of the polycaprolactam type, and also polymers which 
are obtainable both via polyaddition and via polycondensation, such as 
polyethers or polyacetals, 
c. Polycondensation products or precondensates based on bifunctional or 
polyfunctional compounds possessing condensable groups, their 
homocondensation and co-condensation products, and after-treatment 
products, such as, for example, polyesters, especially polyesters which 
are saturated (for example ethylene glycol terephthalic acid polyester) or 
unsaturated (for example maleic acid dialcohol polycondensates as well as 
their crosslinking products with copolymerisable vinyl monomers), 
unbranched or branched (also including those based on polyhydric alcohols, 
such as, for example, alkyd resins), polyamides (for example 
hexamethylenediamine adipate), maleate resins, melamine resins, their 
precondensates and analogues, polycarbonates and silicones, and 
d. Polyaddition products, such as polyurethanes (crosslinked and 
non-crosslinked) and epoxide resins. 
II. Semi-synthetic organic materials, for example, cellulose esters of 
varying degrees of esterification (so-called 21/2-acetate or triacetate) 
or cellulose ethers, regenerated cellulose (viscose or cuprammonium 
cellulose), or their after-treatment products, and casein plastics. 
III. Natural organic materials of animal or vegetable origin, for example 
based on cellulose or proteins, such as cotton, wool, linen, silk, natural 
lacquer resins, starch and casein. 
The organic materials to be optically brightened can be in the most diverse 
states of processing (raw materials, semi-finished goods or finished 
goods). On the other hand, they can be in the form of structures of the 
most diverse shapes, that is say, for example, predominantly 
three-dimensional bodies, such as slabs, profiles, injection mouldings, 
various machined articles, chips, granules or foams, and also as 
predominantly two-dimensional bodies, such as films, sheets, lacquers, 
coverings, impregnations and coatings, or as predominantly one-dimensional 
bodies, such as filaments, fibres, flocks and wires. The said materials 
can, on the other hand, also be in an unshaped state, in the most diverse 
homogeneous or inhomogeneous forms of division, such as, for example, in 
the form of powders, solutions, emulsions, dispersions, latices, pastes or 
waxes. 
Fibre materials can, for example, be in the form of continuous filaments 
(stretched or unstretched), staple fibres, flocks, hanks, textile 
filaments, yarns, threads, fibre fleeces, felts, waddings, flocked 
structures or woven textile fabrics, textile laminates, knitted fabrics 
and papers, cardboards or paper pulps. 
The compounds to be used according to the invention are of importance, 
inter alia, for the treatment of organic textile materials, especially 
woven textile fabrics. Where fibres, which can be in the form of staple 
fibres or continuous filaments or in the form of hanks, woven fabrics, 
knitted fabrics, fleeces, flocked substrates or laminates, are to be 
optically brightened according to the invention, this is advantageously 
effected in an aqueous medium, wherein the compounds in question are 
present in a finely divided form (suspensions, so-called microdispersions 
or possibly solutions). If desired, dispersing agents, stabilisers, 
wetting agents and further auxiliaries can be added during the treatment. 
Depending on the type of brightener compound used, it may prove 
advantageous to carry out the treatment in a neutral or alkaline or acid 
bath. The treatment is usually carried out at temperatures of about 
20.degree. to 140.degree. C, for example at the boiling point of the bath 
or near it (about 90.degree. C). Solutions or emulsions in organic 
solvents can also be used for the finishing, according to the invention, 
of textile substrates, as is practised in the dyeing trade in so-called 
solvent dyeing (pad-thermofix application, or exhaustion dyeing process in 
dyeing machines). 
The new optical brighteners according to the present invention can further 
be added to, or incorporated in, the materials before or during their 
shaping. Thus they can, for example, be added to the compression moulding 
composition or injection moulding composition during the manufacture of 
films, sheets (for example hot milling into polyvinyl chloride) or 
mouldings. 
Where fully synthetic or semi-synthetic organic materials are being shaped 
by spinning processes or via spinning compositions, the optical 
brighteners can be applied in accordance with the following processes: 
Addition to the starting substances (for example monomers) or intermediates 
(for example precondensates or prepolymers), that is to say before or 
during the polymerisation, polycondensation or polyaddition, 
Powdering onto polymer chips or granules for spinning compositions, 
Bath dyeing of polymer chips or granules for spinning compositions, 
Metered addition to spinning melts or spinning solutions, and 
Application to the tow before stretching. 
The new optical brighteners according to the present invention can, for 
example, also be employed in the following use forms: 
a. Mixed with dyestuffs (shading) or pigments (coloured pigments or 
especially, for example, white pigments), or as an additive to dye baths, 
printing pastes, discharge pastes or reserve pastes, or for the 
after-treatment of dyeings, prints or discharge prints. 
b. Mixed with so-called "carriers," wetting agents, plasticisers, swelling 
agents, anti-oxidants, light stabilisers, heat stabilisers and chemical 
bleaching agents (chlorite bleach or bleaching bath additives). 
c. Mixed with crosslinking agents or finishing agents (for example starch 
or synthetic finishes), and in combination with the most diverse textile 
finishing processes, especially synthetic resin finishes (for example 
creaseproof finishes such as "wash-and-wear," "permanent-press" or 
"no-iron"), as well as flameproof finishes, soft handle finishes, 
anti-soiling finishes or anti-static finishes, or anti-microbial finishes. 
d. Incorporation of the optical brighteners into polymeric carriers 
(polymerisation, polycondensation or polyaddition products), in a 
dissolved or dispersed form, for use, for example, in coating agents, 
impregnating agents or binders (solutions, dispersions and emulsions) for 
textiles, fleeces, paper and leather. 
e. As additives to so-called "master batches." 
f. As additives to the most diverse industrial products in order to render 
these more marketable (for example improving the appearance of soaps, 
detergents and pigments). 
g. In combination with other optically brightening substances. 
h. In spinning bath preparations, that is to say as additives to spinning 
baths such as are used for improving the slip for the further processing 
of synthetic fibres, or from a special bath before stretching the fibre. 
i. As scintillators for various purposes of a photographic nature, such as, 
for example, for electrophotographic reproduction or supersensitisation, 
and for the optical brightening of photographic layers, optionally in 
combination with white pigments such as, for example, TiO.sub.2. 
j. Depending on substitution, as laser dyestuffs. 
If the brightening process is combined with textile treatment methods or 
finishing methods, the combined treatment can in many cases advantageously 
be carried out with the aid of appropriate stable preparations which 
contain the optically brightening compounds in such concentration that the 
desired brightening effect is achieved. 
In certain cases, the brighteners are made fully effective by an 
after-treatment. This can represent, for example, a chemical treatment 
(for example acid treatment), a thermal treatment (for example heat) or a 
combined chemical/thermal treatment. Thus, for example, the appropriate 
procedure to follow in optically brightening a range of fibre substrates, 
for example polyester fibres, with the brighteners according to the 
invention, is to impregnate these fibres with the aqueous dispersions (or 
optionally also solutions) of the brighteners at temperatures below 
75.degree. C, for example at room temperature, and to subject them to a 
dry heat treatment at temperatures above 100.degree. C, it being generally 
advisable additionally to dry the fibre material beforehand at a 
moderately elevated temperature, for example at not less than 60.degree. C 
and up to about 130.degree. C. The heat treatment in the dry state is then 
advantageously carried out at temperatures between 120.degree. and 
225.degree. C, for example by heating in a drying chamber, by ironing 
within the specified temperature range or by treatment with dry, 
superheated steam. The drying and dry heat treatment can also be carried 
out in immediate succession or be combined in a single process stage. 
The amount of the new optical brighteners to be used according to the 
invention, relative to the material to be optically brightened, can vary 
within wide limits. A distinct and durable effect is already achievable 
with very small amounts, in certain cases, for example, amounts of 0.0001 
percent by weight. However, amounts of up to about 0.8 percent by weight 
and optionally of up to about 2 percent by weight can be employed. For 
most practical purposes, amounts between 0.0005 and 0.5 percent by weight 
are of preferred interest. 
The new optical brighteners are also particularly suitable for use as 
additives for wash liquors or industrial and domestic washing agents, to 
which they can be added in various ways. They are appropriately added to 
wash liquors in the form of their solutions in water or organic solvents 
or in a finely divided form, as aqueous dispersions. They are 
advantageously added to domestic or industrial washing agents in any stage 
of the manufacturing process of the washing agents, for example to the so 
called "slurry" before spraydrying to the washing powder, or during the 
preparation of liquid washing agent combinations. They can be added either 
in the form of a solution or dispersion in water or other solvents or, 
without auxiliaries, as a dry brightening powder. For example, the 
brighteners can be mixed, kneaded or ground with the detergent substances 
and, in this form, admixed to the finished washing powder. However, they 
can also be sprayed in a dissolved or pre-dispersed form onto the finished 
washing agent. 
Possible washing agents are the known mixtures of detergent substances such 
as, for example, soap in the form of chips and powders, synthetics, 
soluble salts of sulphonic acid half esters of higher fatty alcohols, 
arylsulphonic acids with higher and/or multiple alkyl substituents, 
sulphocarboxylic acid esters of medium to higher alcohols, fatty acid 
acylaminoalkyl- or acylaminoaryl-glycerolsulphonates, phosphoric acid 
esters of fatty alcohols and the like. Possible so-called "builders" which 
can be used are, for example, alkali metal polyphosphates and 
polymetaphosphates, alkali metal pyrophosphates, alkali metal salts of 
carboxymethylcellulose and other "soil redeposition inhibitors," also 
alkali metal silicates, alkali metal carbonates, alkali metal borates, 
alkali metal perborates, nitrilotriacetic acid, ethylenediaminotetraacetic 
acid, and foam stabilisers, such as alkanolamides of higher fatty acids. 
The washing agents can further contain, for example: antistatic agents, 
skin protection agents which restore fat, such as lanolin, enzymes, 
anti-microbial agents, perfumes and dyestuffs. 
The new optical brighteners have the particular advantage that they are 
also active in the presence of active chlorine donors, such as, for 
example, hypochlorite, and can be used without significant loss of the 
effects in wash liquors containing non-ionic washing agents, for example 
alkylphenol polyglycol ethers. 
The compounds according to the invention are added in amounts of 0.005-1% 
or more, relative to the weight of the liquid or pulverulent, finished 
washing agent. Wash liquors which contain the indicated amounts of the 
optical brighteners claimed impart a brilliant appearance in daylight when 
used to wash textiles of cellulose fibres, polyamide fibres, cellulose 
fibers with a high quality finish, polyester fibres, wool and the like. 
The washing treatment is carried out, for example, as follows: 
The textiles quoted are treated for 1 to 30 minutes at 20.degree. to 
100.degree. C in a wash liquor which contains 1 to 10 g/kg of a composite 
washing agent containing a builder and 0.05 to 1%, relative to the weight 
of washing agent, of the brighteners claimed. The liquor ratio can be 1:3 
to 1:50. After washing, rinsing and drying are carried out as usual. The 
wash liquor can contain 0.2 g/l of active chlorine (for example as 
hypochlorite) or 0.1 to 2 g/l of sodium perborate, as a bleaching 
additive. 
The new optical brighteners are also suitable, depending on substitution, 
as laser dyestuffs for emission in the region of shortwave visible light.

In the examples, unless otherwise indicated, parts are always parts by 
weight and percentages are always percentages by weight. Unless otherwise 
noted, melting points and boiling points are uncorrected. 
EXAMPLE 1 
4.00 g (0.03 mol) of 2-methyl-benzoxazole of the formula 
##STR21## 
7.50 g (0.03 mol) of 2-phenyl-4-(p-formylphenyl)-2H-1,2,3-triazole of the 
formula 
##STR22## 
(melting point: 149.degree. C), 6.55 g (0.035 mol) of toluene-4-sulphonic 
acid monohydrate and 2.85 g (0.039 mol) of dimethylformamide are stirred 
in 60 ml of xylene for 90 minutes under reflux, in a sulphonating flask 
which is provided with a water separator, during which 1.17 ml of water 
are isolated by xylene/water azeotropic distillation. The reaction mixture 
is then cooled to room temperature and the product is filtered off and 
washed with 50 ml of toluene. The olive-green product is suspended in 
water, the aqueous suspension is adjusted to pH 10 with 2 N sodium 
hydroxide solution, warmed to 40.degree. C and filtered whilst warm. This 
gives 10.1 g (corresponding to 92% of theory) of the compound 
2-[-4-(2'-phenyl-(2H)-1,2,3-triazolyl(4')-styryl)-]-benzoxazole of the 
formula 
##STR23## 
as a green-yellow product. After recrystallising twice from chlorobenzene 
(fuller's earth) 6.4 g of greenish-tinged yellow crystals of melting point 
217.degree.-218.degree. C are obtained. 
Analysis: C.sub.23 H.sub.16 N.sub.4 O (364.39) 
calculated: C, 75.81; H, 4.43; N, 15.38. 
found: C, 75.80; H, 4.20; N, 15.40. 
The compounds of the formula 
##STR24## 
listed in the table which follows can be manufactured in an analogous 
manner. 
TABLE I 
__________________________________________________________________________ 
No. 
U.sub.1 
U.sub.2 U.sub.3 
U.sub.4 
Z Melting point.degree. C 
__________________________________________________________________________ 
105 
H H 
##STR25## 
H H 215 - 216 
106 
H SO.sub.2 CH.sub.3 
H H H 264 
107 
H CH.sub.3 H H H 214 
108 
H CH.sub.2 CH.sub.2 CN 
H H H 208 
109 
##STR26## H H H 198 
110 
H 
##STR27## 
H H H 219 
111 
H CH.sub.3 CH.sub.3 
H H 224 
112 
H CH.sub.3 H CH.sub.3 
H 200 
113 
H OCH.sub.3 
H H H 205 
114 
H C(CH.sub.3).sub.3 
H H H 172 
115 
H Cl H H H 223 
116 
H 
##STR28## 
H H H 180 
117 
H 
##STR29## 
H H H 253 
118 
H COOCH.sub.3 
H H H 229 
119 
H NaSO.sub.3 
H H H recrystallised 
from water/ethanol 
120 
H CH.sub.2 CH.sub.2 CN 
H H Cl 184 
121 
H H H H Cl 186 
122 
H H H H 
##STR30## 
187 
__________________________________________________________________________ 
example 2 
4.39 g (0.021 mol) of 5-phenyl-2-methyl-benzoxazole of the formula 
##STR31## 
4.54 g (0.02 mol) of 
2-(p-methylsulphonyl-phenyl)-4-(p-formylphenyl)-(2H)-1,2,3-triazole of the 
formula 
##STR32## 
(melting point: 330.degree. C), 4.37 g (0.023 mol) of toluene-4-sulphonic 
acid monohydrate and 1.90 g (0.026 mol) of dimethylformamide are stirred 
in 50 ml of xylene for 1 hour under reflux, in a sulphonating flask which 
is provided with a water separator. The white suspension is converted to a 
brown solution, 2.00 ml of water being isolated by xylene/water azeotropic 
distillation. The reaction mixture is then cooled to room temperature and 
the product is filtered off and washed with 60 ml of toluene. The brown 
product is suspended in water, the aqueous suspension is adjusted to pH 10 
with 2 N sodium hydroxide solution, warmed to 40.degree. C and filtered 
whilst warm. This gives 5.7 g (corresponding to 79.3% of theory) of the 
compound 
2-[-4-(2'-p-methylsulphonylphenyl)-(2'H)-1',2',3'-triazolyl(4')-styryl-]-b 
enzoxazole of the formula 
##STR33## 
as a pale yellow product. After recrystallising twice from 
dimethylformamide (active charcoal) 2.7 g of greenishtinged yellow 
crystals of melting point above 300.degree. C are obtained. 
Analysis: C.sub.30 H.sub.22 N.sub.4 O.sub.3 S (518.60) 
calculated: C, 69.48; H, 4.28; N, 10.80. 
found: C, 69.40; H, 4.40; N, 10.90. 
2-Phenyl-4-(p-formylphenyl)-2H-1,2,3-triazole of the formula 
##STR34## 
used as the starting material for the manufacture of the compound of the 
formula (103) can be prepared as follows: 
5.7 g (0.065 mol) of 2-nitropropane are introduced into a solution of 1.15 
g (0.05 mol) of sodium in 1,000 ml of ethanol at about 20.degree. C. The 
reaction mixture is stirred for 1 hour and warmed to 35.degree. C, and 
16.0 g (0.05 mol) of 2-phenyl-4-(p-bromomethylphenyl)-2H-1,2,3-triazole 
are now added. The solution is then stirred for 20 hours, without external 
warming, and the suspension formed is filtered off and washed with water 
until neutral. A further amount of product can be obtained by 
concentrating the mother liquor. After recrystallisation from ethanol, 8.9 
g (corresponding to 69.5% of theory) of the compound of the formula (204) 
are obtained as a white crystalline powder of melting point 149.degree. C. 
The two aldehydes of the formulae 
##STR35## 
melting point: 210.degree. C and 
##STR36## 
melting point: 140.degree. C, can be manufactured according to the same 
process. 
2-Phenyl-4-(p-formylphenyl)-5-chloro-v-triazole of the formula 
##STR37## 
is manufactured as follows: 
1-N-Oxy-2-phenyl-4-tolyl-v-triazole is dissolved in a dioxane/water solvent 
mixture, hydrogen chloride is passed in at 90.degree. C for 9 hours and 
the reaction mixture is then evaporated and the residue is recrystallised 
from hexane. The product, that is to say 
2-phenyl-4-tolyl-5-chloro-v-triazole, (melting point 
87.degree.-88.degree.l C) is reacted with bromosuccinimide, in carbon 
tetrachloride as the solvent and using a catalytic amount of dibenzoyl 
peroxide, to give 2-phenyl-4-(p-bromomethylphenyl)-5-chloro-v-triazole 
(melting point 121.degree.-122.degree. C). From this compound, the 
compound 2-phenyl-4-(p-formylphenyl)-5-chloro-v-triazole of melting point 
119.degree. C is manufactured according to the same process as that 
described for the compound (204). 
2-Methyl-benzoxazole-5-propionitrile (starting material for the compounds 
(108) and (120)) of the formula 
##STR38## 
is manufactured as follows: 
4-Hydroxy-phenyl-propionitrile is nitrated in glacial acetic acid with 65% 
strength nitric acid at 10.degree.-15.degree. C, in the course of 2 hours, 
the 3-nitro-4-hydroxyphenyl-propionitrile (melting point = 104.degree. C) 
is reduced with hydrogen, using 5% strength palladium charcoal as the 
catalyst, in ethanol at room temperature to give 
3-amino-4-hydroxyphenyl-propionitrile (melting point = 125.degree. C) and 
the amine compound is acetylated in toluene with molar equivalent amounts 
of acetic anhydride. The 3-acetamino-4-hydroxyphenyl-propionitrile 
(melting point = 191.degree.-192.degree.) is slowly warmed to 
250.degree.-260.degree. and then rapidly heated up to 300.degree.. The 
melt is cooled to room temperature, the oil is taken up in an alkaline 
aqueous solution, the pH of which is adjusted to 10, and the water/oil 
emulsion is extracted by shaking with chloroform. The chloroform solution 
is separated from the aqueous phase, dried with sodium sulphate and 
concentrated. The pink-beige needle crystals thus obtained melt at 
69.degree.-70.degree. C. 
EXAMPLE 3 
A polyester fabric (25 g) is placed in a bath, which contains, per liter, 
10 g of a condensation product of aromatic sulphonic acids, 25 g of an 
aromatic carboxylic acid ester, as the emulsifier, and 5 g of sodium 
dihydrophosphate and which is adjusted to a pH value of 5 with acetic 
acid, in a liquor ratio of 1:40. After a dyeing time of one hour at the 
boiling point in the presence of 0.05 g/l of a brightener of the formula 
(103) or (107), the fabric exhibits a brilliant brightening with good 
fastness to light. 
EXAMPLE 4 
0.01 percent by weight of a brightener of the formula (103), (105), (106), 
(107), (112) or (203) is milled into opaque soft polyvinyl chloride. The 
polyvinyl chloride exhibits a neutrally white brightening with good 
fastness to light. 
EXAMPLE 5 
100 Parts of polyester granules consisting of terephthalic acid ethylene 
glycol polyester are intimately mixed with 0.05 part of a compound of the 
formula (107) or (108) and the mixture is fused at 285.degree. C, whilst 
stirring. After extruding the spinning composition through customary 
spinnerets, strongly brightened polyester fibres of good fastness to light 
are obtained. 
The abovementioned compounds can also be added to the starting materials 
before or during the polycondensation to give the polyester. 
EXAMPLE 6 
A polyester fabric (for example "DACRON") is padded at room temperature 
(about 20.degree. C) with an aqueous dispersion which contains, per liter, 
2 g of one of the compounds of the formula (103), (107) or (108) and 1 g 
of an addition product of about 8 mols of ethylene oxide and 1 mol of 
p-tert.-octylphenol, and is dried at about 100.degree. C. The dry material 
is then subjected to a heat treatment of 170.degree. to 220.degree. C, 
which, depending on the temperature, lasts 2 minutes to a few seconds. The 
material treated in this way exhibits a strong brightening effect of good 
fastness to light. 
EXAMPLE 7 
0.06 g of Tinegal NA (= alkyl polyglycol ether) is added to 100 ml of 
water. 
A solution of an optical brightener of the formula (103) is prepared by 
dissolving 1 g in 1,000 ml of dimethylformamide. 3 ml of this stock 
solution are added to the solution described above. This aqueous solution 
or dispersion, which contains the brightener, is warmed to 60.degree. C, 
and a nylon fabric weighing 3 g is then placed in the solution. The 
temperature is increased in the course of 10-15 minutes to 
92.degree.-95.degree. C and the bath is left at this temperature for 30 
minutes. The fabric is then rinsed for 2 minutes in running cold water and 
is then dried for 20 minutes at 60.degree. C. 
The fabric treated in this way exhibits a significant brightening effect of 
good fastness to light. 
Analogous effects are achieved with the optical brighteners of the formulae 
(107) or (108). 
EXAMPLE 8 
A fabric of polyamide fibre (Perlon) is placed into a bath, which, 
(relative to the weight of the material) contains 0.1% of one of the 
brighteners of the formulae (103), (107) or (108), and, per liter, 1 g of 
80% strength acetic acid and 0.25 g of an addition product of 30 to 35 
mols of ethylene oxide and one mol of industrial stearyl alcohol, in a 
liquor ratio of 1:40 at 60.degree. C. The bath is warmed to the boiling 
point in the course of 30 minutes and is maintained at the boil for 30 
minutes. After rinsing and drying the fabric, a strong brightening effect 
of good fastness to light is obtained. 
If a fabric consisting of polyamide-66 (nylon) is used instead of the 
fabric consisting of polyamide-6, brightening effects which are similarly 
good are achieved. 
Finally, the process can also be carried out under high temperature 
conditions, for example for 30 minutes at 130.degree. C. For this type of 
use it is advisable to add 3 g/l of hydrosulphite to the liquor. 
EXAMPLE 9 
0.4 g of a washing agent of the following composition is added to 100 ml of 
water: 
______________________________________ 
Dodecylbenzenesulphonate 
16% 
Fatty alcohol sulphonate 
4% 
Na tripolyphosphate 35% 
Tetra-Na pyrophosphate 7% 
Mg silicate (MgSiO.sub.3) 
2% 
Na disilicate (Na.sub.2 (SiO.sub.3).sub.2) 
7% 
Carboxymethylcellulose 1% 
Ethylenediaminetetraacetic acid 
(sodium salt) 0.5% 
Sodium sulphate decahydrate 
about 25%* 
Water 2.5% 
______________________________________ 
*(The washing agent can also contain 10-20% of Na perborate or another 
agent which releases oxygen instead of sodium sulphate decahydrate). 
A solution of the optical brightener of the formula (103) is prepared by 
dissolving 1 g in 1,000 ml of dimethylformamide. 2 ml of this stock 
solution are added to the solution described above. This aqueous solution 
(or dispersion) containing the brightener is warmed to 60.degree. C. A 
nylon fabric weighing 3 g is then placed into the solution and is treated 
at this temperature for 30 minutes. The fabric is then rinsed for 2 
minutes in running cold water and then dried for 20 minutes at 60.degree. 
C. 
The fabric treated in this way exhibits a marked brightening effect of good 
fastness to light. 
Analogous effects are achieved, inter alia, with the optical brighteners of 
the formula (106), (107) and (108) 
EXAMPLE 10 
7 g of anatase (TiO.sub.2) are added to 1,400 ml of dimethylformamide and 
then 350 g of polyacrylonitrile, in powder form, are added and the mixture 
is processed by means of highspeed stirrer to give a viscous composition. 
5 mg of a brightener of the formula (105), (109) or (112) are added to 50 
g of this 20% strength solution. This mixture is homogenised by stirring 
and then kept under a vacuum for one hour to enable the air bubbles formed 
to diffuse out. After this, the composition is poured onto a glass plate 
and drawn out with a metal rod to give a uniform film. The 
polyacrylonitrile film is then dried in a drying cabinet for about 15 
minutes at about 50.degree. C, with ventilation (draught of air), and then 
dried at room temperature with slight ventilation. The polyacrylonitrile 
film can be easily separated from the glass plate. It possesses a 
substantially higher white effect with good fastness to light than a film 
manufactured identically which does not contain the optical brightener.