US3341530A - Naphtho(1, 2)triazole brighteners for fine fabrics - Google Patents

Description

3,341,530 NAPHTHO(1,2)TRIAZOLE BRIGHTENERS FOR FINE FABRICS Albert F. Strobel, Delmar, and Sigmund C. Catlno, Castleton, N.Y., assignors to General Aniline 81 Film Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed May 24, 1965, Ser. No. 458,369

12 Claims. (Cl. 260-240) This application is a continuation-in-part of our applications Ser. Nos: 40,197, filed July 1, 1960, now abandoned; 113,575, filed Mar. 31, 1961, now abandoned, and 185,189, filed Apr. 5, 1962, now abandoned.

This invention relates to a new class of fluorescent naphthotn'azole compounds possessing new and useful properties which render them particularly useful as fluorescent optical bleaching or whitening agents for fine fabrics, such as nylon, Dacron, Orlon and the like.

It is well established that textiles tend to develop a yellowish shade on ageing which cannot be removed by ordinary methods of bleaching or washing. The heretofore used methods of blueing white materials with blue pigments or fugitive blue dyestufis have become quite obsolete in modern laundry practice and have been largely superceded by methods employing fluorescent optical bleaching agents or brighteners as additives to the soap or detergent in the washing bath. These brightening agents are usually conveniently supplied commercially in the form of intimate admixtures with the soap or detergent in bars, flakes, powders, etc. The fluorescent optical bleaching agents perform their desired function by virtue of their characteristic absorption of ultraviolet radiations and subsequent conversion of this energy to light energy within the visible spectrum. This converted and emitted light energy tends to neutralize any yellowness of the material and thereby increase the apparent whiteness thereof.

It is known that blue-fiuorescing 2-(4-styrylphenyl)- 2H-naphtho[l,2]triazole compounds (containing a sulfonic acid group in the stilbene nucleus) can be used from a neutral to a weakly acid bath for the brightening of wool and cellulose fibers. None of them, however, have appreciable afiinity for the synthetic fibers such as Dacron and Orlon made from terephthalic acid and ethylene glycol, acrylonitrile, etc. The lack of afiinity is probably due to the fact that the fine fabrics like Dacron and Orlon, being strongly hydrophobic materials, are not penetrated by these relatively water soluble sulfonated products.

It is also known that the sulfonic acid substituent in the stilbene nucleus of the above foregoing 2-(4-styrylphenyl)-2H-naphtho[1,2]triazoles can be replaced by cyano, sulfone and sulfonamide groups to produce optical brightening agents which are useful for example in brightening paraflin, polymeric synthetic materials such as polymeric amides from ethylene diamine and adipic acid, polyvinyl chloride, polyacrylonitrile, polyacrylic acid esters and copolymers of these materials, cosmetic preparations, ointment bases and the like.

United States Patent 2,784,183 pertains to brighteners which have sulfonic acid or other ionic substituents as an integral part of the molecule. We have found that the ionic compounds of this patent do not have afiinity for line fabrics like Dacron and Orlon.

Even when the ionic groups which are present in these compounds are substituted by a non-ionic nitrile group, as in United States Patent 2,972,611, the non-ionic compounds do not have outstanding aflinity for fine fabrics.

We have now discovered that certain fluorescent naphthotriazoles, free from sulfonic and carboxylic acid groups as well as cyano, sulfone and sulfonamide groups, are

intone m-r 3,341,530 Patented Sept. 12, 1967 "ice readily incorporated in specified amounts into polyamides (nylon), polyesters (e.g., Dacron), polyvinyl chloride, polyvinylidene chloride, polystyrene, polyurethane, polyethylene, polyacrylonitrile (e.g., Orlon), and similar film, fiber and fabric forming materials as effective brightening agents. These new fluorescent naphthotriazoles are especially unusual in that they have great affinity for nylon, and superior brightening power on nylon over the corresponding sulfone and sulfonamide substituted 2-(4-styrylphenyl)-2H-naphtho[1,2]triazoles as well as cyano substituted derivatives of the same. In fact, we have found that these new fluorescent naphthotriazoles have exceedingly high brightness and whitening power in melt application on ethylene glycolterephthalic acid polyester fabric of any brightener we have experimented with, either of our own synthesis or with competitive products. In this connection, it is interesting to note that these fluorescent naphthotriazoles are outstanding on nylon, and are particularly adaptable on films, fibers and fabrics made from polyvinyl chloride, polyvinylidene chloride, polystyrene, polyethylene, polymethyl methacrylate, cellulose nitrate and polyurethane.

The fluorescent naphthotriazoles, i.e., 2-(2-carbamyl- 4-styrylphenyl)-2H-naphtho[1,2]triazoles prepared in accordance with the present invention are characterized by the following general formulae:

wherein R and R represent either hydrogen, halogen such as chlorine, bromine, iodine or fluorine, lower alkyl such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl and lower alkoxy such as methoxy, ethoxy, propoxy, butoxoy, isobutoxy, cyclohexyloxy, and the like. R represents either hydrogen, alkyl, such as methyl, ethyl, propyl, butyl, cyclo hexyl, etc., dialkylamino alkyl, such as dimethyl aminoethyl, dimethyl aminopropyl, dimethyl aminobutyl, diethyl aminobutyl, dipropyl aminoethyl, dipropyl aminobutyl, dibutyl aminoethyl, dibutyl aminobutyl, dicyclohexylaminoethyl, dicyclohexylaminopropyl, dicyclohexylaminobutyl, etc., morpholino-N-alkyl and piperidino-N-alkyl, wherein the alkyl group contains from 2 to 4 carbon atoms, or hydroxyalkyl, e.g., hydroxyethyl, hydroxypropyl, hydroxybutyl, etc., R represents an alkyl group of from 1 to 4 carbon atoms such as methyl, ethyl, propyl, isoproyl, butyl, isobutyl, hydroxyalkyl of the same value as in R and the like, and R represents the atoms necessary to complete a 5- or 6- membered heterocyclic ring system with the nitrogen atom and selected from the class consisting of morpholino,

3 piperidino, hexamethyleneimino, pyrrolidino, imidazolo, pyrazolo, 1,2,3-triazolo, 4-pyridono, -piperidono, and the like.

The unsubstituted carboxamide is prepared by diazotizing a stilbene of the formula:

R1 CONH:

wherein R and R have the same values as above, in glacial acetic acid adding hydrochloric acid and sodium nitrite to the amine as a solution or suspension in water or hydrochloric acid. After diazotization is complete, 2- napthylamine, as the hydrochloride or as a slurry, is added to the diazo in equimolar amount. After coupling has occurred, the monoazo dye is oxidized to the triazol, for example, by heating with copper sulfate in a basic solvent such as pyridine or ,8,a-picoline, and the like. The brightener is isolated by first precipitating and filtering the copper as the sulfide and then separating from the solvent either by steam distillation or dilution with water and cooling, and then filtering. The substituted carboxamides are prepared by diazotizing a stilbene of the formula:

wherein R and R have the same values as above, in acetic acid by adding thereto hydrochloric acid and sodium nitrite, preferably in aqueous solution, to the amine at a temperature of -10" C. After diazotization is complete, Z-naphthylamine, as the hydrochloride or as a slurry, is added to the diazo in equimolar amount, care being exercised that the reaction remains weakly acid. After coupling has occurred, the monoazo dye is oxidized to the triazole, for example, by heating with copper sulfate in a basic solvent such as pyridine or ,6,a-picoline, and the like. The resulting compound is then treated with thionyl chloride or a mixture of phosphorous oxychloride and phosphorus pentachloride in the known manner to convert the carboxylic acid group to the acid chloride. The latter is then further reacted with an appropriate amine in the known manner to give products shown by Formulas l and 2 above.

Alternatively, the fluorescent substituted carboxamido naphthotriazoles of the present invention are prepared from the intermediates of the following formula:

CH=CH -No.

n, doNH-R, Q Q

CH=CH No,

R1 ON(R4): and

wherein R R R R and R have the same values as above by reducing the nitro group to the amino group, diazotizing and coupling with Z-naphthylamine and then oxidizing the thus formed azo dye to form the triazole compound.

The stilbene intermediates characterized by Formulae a, b and c are prepared in accordance with the method of Pfeiifer, Berichte, 44, 1119, by condensing the methyl ester of S-nitro-o-tolucarboxylic acid with anyone of the following benzaldehydes:

benzaldehyde 0-, m-, and p-bromobenzaldehyde 0-, mand p-chlorobenzaldehyde 4 2,3-, 2,4-, 3,4- and 2,6-dichlorobenzaldehyde 0-, mand p-tolualdehyde S-bromo-Z-methoxybenzaldehyde 5-chloro-2-methoxybenzaldehyde 2-methovy-m-tolualdehyde S-methoxy-o-tolualdehyde 3-bromo-4-cthoxybenzaldehyde 4-butoxy-3-chl0robenzaldehyde 0-, mand p-methoxybenzaldehyde 2,4-dibromobenzaldehyde 0-, mand p-ethoxybenzaldehyde 3,4-diethoxybenzaldehyde o-, mand p-propoxybenzaldehyde 2,3-dimethoxybenzaldehyde o-, mand p-butoxybenzaldehyde p-fluorobenzaldehyde 4-chloro-o-tolualdehyde 3-chloro-p-tolualdehyde 2,4-, 2,5- and 3,5-dimethylbenzaldehyde 4- and 5-isopropyl-o-tolualdehyde 2,4- and 2,5-diethylbenzaldehyde p-tertiarybutylbenzaldehyde p-ethylbenzaldehyde p-iodobenzaldehyde The foregoing condensation products which contain a carboxylic acid group in the 2-position and a nitro group in the 4-position of the stilbene nucleus are then converted to the corresponding acid chlorides in the known manner, i.e., by treatment with thionyl chloride and finally reacting the latter with an appropriate amine in the conventional way. The resulting product is then subjected to the reduction of the nitro group to yield the 4-amino stilbene derivative. The resulting amino stilbene intermediate is then further treated by diazotization and coupling, followed by oxidation as will be noted from the following examples.

Alternatively, the stilbene intermediates characterized by Formulae a, b and 0 may be prepared by the reaction of the appropriate benzaldehyde with the appropriate 5- nitro-o-toluamide according to the method of Macovski, Georgescu and Bachmeyer, Ben, 74B 1279-84 (1941); Chem. Abstracts, 36, 4813 (1942). The resulting product is then subjected to the reduction of the nitro group to yield the 4-aminostilbene derivative. The resulting aminostilbene intermediate is then further treated by diazotization and coupling, followed by oxidation to the triazole compound.

The unsubstituted carboxamido nitro stilbene intermediate may be prepared most efiicaciously by condensing S-nitro-o-tolunitrile with any of the foregoing benzaldehydes whereby the nitrile is converted in the reaction to a CONH group. The nitro group in the 4-position of the stilbene nucleus is further treated, as above, to reduce it to an amino group.

As examples of organic amines which may be reacted with the carboxylic acid chloride substituted naphthotriazoles or the 4-amino stilbene derivatives, the following are illustrative:

Methylamine Ethylamine Propylamine Butylamine Dimethylaminoethylamine Dimethylaminopropylamine Dimethylaminobutylamine Diethylaminoethylamine Diethylaminopropylamine Diethylaminobutylamine Dipropylaminoethylamine Dipropylaminopropylamine Dipropylaminobutyl amine Dibutylaminoethylamine Dibutylaminopropylamine Dibutylaminobutylamine Morpholinoaminoethylamine Morpholinoaminopropylamine Morpholinoaminobutylamine Piperidinoaminoethylamine Piperidinoarninomethylamine Dimethylamine Diethylamine Dipropylamine Dibutylamine Imidazole Morpholine Piperidine 1,2-dihydropyridine Pyrrolidine -Piperidone 4-pyridone Pyrazole 1 ,2,3-tn'azole 2-aminoethanol l-amino-Z-propanol 2,2'-iminodiethano1 In connection with the naphthotriazoles of Formulas 1, 2 and 3, it is to be noted that those which have an ionic substituent in the 3-position of the 4-styrylphenyl configuration, such as, for example,

are water soluble and dye both nylon and Orlon. Those which do not contain a water solubilizing group, such as CONH CONl-I=alkyl, are water insoluble and dye nylon and Dacron. Those fluorescent dyes which contain a hydroxyl solubilizing group such as, for example, -CON1-IC H OH are more water soluble and dye nylon preferentially.

The brightening agents of this invention are applied either from an aqueous textile bath or by melt incorporation into the aforementioned film, fibre and fabric-forming polymers. As to fabrics, the brightening agents may be applied in dispersed form. The dispersion may be made by kneading the brightener with a suitable dispersing agent in a Werner-Pfleiderer mixer, or it may be dispersed by dissolving the brightener in a suitable solvent and pouring the solution into water giving a finely divided precipitate. The dispersed brightener is usually applied to the fabric by heating in water together with the fabric for about 45 minutes at a temperature near the boil. The amount of brightener may vary a great deal, and in fact may range from 0.0035% to 0.5% based on the weight of the fiber.

The following examples will serve to illustrate the present invention without being deemed limitative thereof. Parts are by weight unless otherwise indicated.

EXAMPLE I JONH:

The intermediate having the formula:

H H Cl C=C NO:

( JONH:

6 This mixture is shaken well and allowed to stand in a closed vessel for several days. The charge is filtered, and the presscake washed on the funnel with 100 ml. of glacial acetic acid. The cake is, ground in a mortar with 50 mls. of glacial acetic acid, filtered, washed with an additional 50 mls. of glacial acetic acid and finally washed with 100 mls. of water and dried in air to yield the crude intermediate. The melting point of this product is 272.5 C.

All of the above crude nitro intermediate is slurried in about 500 mls. of 1% aqueous sodium hydroxide solution at 70 C., filtered and then washed with 200 mls. of water. The resulting cake is once more reslurried in 500 mls. of 1% aqueous sodium hydroxide solution at 70 C., filtered, washed with 500 mls. of water and dried at C. in air to give the yield of 46 grams of the intermediate.

The nitro intermediate as obtained above is reduced to the amine in the following manner:

Into a 1-liter flask are charged 110 mls. of dimethyl formamide, 55 mls. of water, 39 grams of iron borings 60 mesh, and 6.7 mls. of concentrated hydrochloric acid. The material is then heated for 10 minutes at 95 C. and a solution of 30.2 grams of the reslurried nitro material obtained as above in 150 mls. of dimethyl formamide was added in small portions at 100 C. The product was heated for 1 hour at 107-l10 C. The charge is then neutralized with soda ash to a negative test with potassium ferricyanide or phenolphthalein alkalinity. The charge is filtered through super cel at 108 C. and the cake washed with 200 mls. of hot dimethyl formamide. The filtrate is then diluted to 4 liters volume with water, filtered and washed with additional 2 liters of water and then air dried to give 24 grams of amine product.

11.8 grams of the amine product is dissolved at 80 C. in 300 mls. of glacial acetic acid and a solution of 21 mls. of concentrated hydrochloric acid in 75 mls. of water is added. The resulting charge is cooled to 0 C. and 8.6 mls. of sodium nitrite solution (38.5% wt./vol.) (=.047 mole) is added dropwise to the amine hydrochloride slurry at 0-5 C. and stirred for A hour at 5-10 C., followed by addition of 3 mls. of 10% aqueous sulfamic acid solution to destroy excess nitrous acid. A solution of 6.75 grams of 2-naphthylamine is dissolved at C. in 250 mls. of water and 8.4 mls. of concentrated hydrochloric acid, filtered by gravity and added slowly to the diazo at 0-5 C. the resulting slurry is stirred for 2 hours at 0-10 C. and then the charge filtered and the cake washed with 1 liter of cold water.

The resulting dyestuff after drying is dissolved at 85 C. in 2400 mls. of picoline and at a temperature of C. a solution consisting of 27.2 grams of copper sulfate in 50 mls. of water is then added. The material is heated for 2 hours at reflux. The copper is precipitated with sodium sulfide, 8 filtered at 98 C. and then washed with 250 mls. of picoline at a temperature of 120 C. The combined filtrate and picoline wash is cooled to 5 C. and filtered. Then the brightener cake is washed with mls. of picoline at 0 C., followed by washing with 250 mls. of water. The resulting brightener is dried at 80 C. in air.

In order to determine what brightening effect, if any, the replacement of the carboxylic acid amide group, in the stilbene moiety of the fluorescent naphthotriazole compound prepared as above, by a cyano group, a .05% dyeing (O.W.F.) on nylon of the instant compound is compared with a .05% dyeing of the compound of the formula:

The dyeings are made by dissolving .05 gram of dye in 100 mls. of dimethyl formamide. 5 mls. of this solution is dissolved in 150 mls. of an 0.1% aqueous Peregal solution (commercially available surfactant). A gram swatch of nylon is dyed at 100 F. for 45 minutes, rinsed 3 times and dried.

The reason for a dyeing made at 100 F. is that many women wash their personal clothing in wash basins and other facilities, which is normally around 100 F., and not in washing machines where hot water, above 100' F. is generally employed.

Comparative brightness readings are made as follows:

EXAMPLE V Nylon Dyeing at 100 F.

N CI asQ/ O NH:

On nylon at 100 F. compound (1) is far superior to compound (2) despite the fact that neither of the compounds is ionic. The superiority is very distinctive by comparative brightness readings. This is wholly unexpected and surprising, since compounds (1) and (2) are both free from ionic substituents.

EXAMPLE II N H H Cl CONH: N

Example I is repeated with the exception that 42.2 grams of p-chlorobenzaldehyde are replaced by 36.0 grams of p-tolualdehyde.

EXAMPLE 111 N aQas N l C O NH: N

Example I is repeated with the exception that 42.2 grams of p-chlorobenzaldehyde are replaced by 52.5 grams of 2,4-dichlorobenzaldehyde.

EXAMPLE IV Example I is repeated with the exception that 42.2 grams of p-chlorobenzaldehyde are replaced by 40.8 grams of o-methoxybenzaldehyde.

EXAMPLE VI CHH CONH:

Example I is again repeated with the exception that 42.2 grams of p-chlorobenzaldehyde are replaced by 31.8 grams of benzaldehyde.

In order to determine what brightening effect, if any, the replacement of the carboxylic acid amide group, in the stilbene moiety of the fluorescent naphthotriazole compound prepared as above, by the cyano group, a .05% dyeing (O.W.F.) on nylon of the instant compound is compared with a .05% dyeing of the compound of the formula:

The dyeings are made by dissolving .05 gram of dye in mls. of dimethyl formamide. 5 mls. of this solution are dissolved in 150 mls. of a 0.1% aqueous solution of Peregal O. A 5 gram swatch of nylon is dyed at F. for 45 minutes, rinsed 3 times and dried.

Comparative brightness readings are made as follows:

Nylon Dyeing at; 130 F.

CONH: N K) H H l CN N On nylon at 130 F. compound (3) is far superior to compound (4) despite the fact that neither of the compounds is ionic. The superiority is very distinctive by comparative brightness reading and also by visual observation. Due to the fact that the square of the brightness is proportional to the concentration used (30*:900; 25 =625), it requires about 40% more of compound (4) to achieve the same degree of brightness as compound (3). This is wholly unexpected, since compounds 1 and 3 are both free from ionic substituents. The unexpected superiority of (3) over (4) on nylon is of great commercial importance.

Furthermore, in order to ascertain the merit of the instant compound as compared with related ionic substituted compounds 0.05% by weight dyeings are made on Dacron polyester cloth of the instant brightener (3) and the ionic brighteners of the formulae:

(5) 35 N/T soar Q ij =C --N Q Q solNnso n, U

Dacron" Dyeing at On Dacron at 190200 F. compound (3) is far superior to compounds (5) and (6). The superiority is very distinctive by comparative brightness readings. This great difference is probably due to the fact that compound (3) is non-ionic whereas compounds (5) and (6) are ionic,

and compound 3) has much greater affinity for a hydrophobic fiber such as Dacron than the ionic compounds (5) and (6).

In order to ascertain the merit of this compound against a related ionic compound on Arnel cellulose triaeetate fiber and cellulose acetate fiber 0.01% by weight dyeings are made on Arnel" and also cellulose acetate of the instant brightener (3) and ionic substituted brightener (6).

The dyeings are made by dissolving .05 gram of dye in mls. of dimethyl formamide. 1 ml. of this solution is dissolved in mls. of a 1% aqueous Peregal 0 solution. A 5 gram swatch of fabric is dyed at l90200 F, for 45 minutes, rinsed 3 times and dried.

Arnel" Cellulose Dyeing at Acetate -200 F. D yein r at Compound (3) 12 41 Compound (6) 1 20 On both ArneY and cellulose acetate compound (3) is far superior to compound (6). The superiority is very distinctive by comparative brightness readings. This very great difference is probably due to the fact that compound (3) is nonionic whereas compound (6) is ionic, and compound (3) has a much greater afiinity for hydrophobic fibers such as ArneF and cellulose acetate than the related ionic substituted compound.

Further, in order to determine what brightening effect, if any, the replacement of the carboxylic acid amide group, in the stilbene moiety of the fluorescent naphthotriazole compound prepared as above, by a carboxylic acid group, a 01% dyeing (O.W.F.) on Dacron" of the instant compound is compared with a .01% dyeing of the compound of the formula:

2700K L/ i 1 1 Comparative brightness readings are made as follows:

Dacron" Dyeing at 190200 F. (3) 24 3 EXAMPLE VII N CH CHZCHQN Cl ONH;

Example I is again repeated with the exception that 42.2 grams of p-chlorobenzaldehyde were replaced by 46.4 grams of 3-chloro-p-tolualdehyde.

EXAMPLE VIII N H. CEeCH N H; C O N H: N i

Example I is again repeated with the exception that 42.2 grams of p-chlorobenzaldehyde are replaced by 40.2 grams of 2,4-dimethylbenzaldehyde.

Application The application of each of the brighteners of Examples I to VIII inclusive to nylon is carried out by dissolving 0.05 gram of each brightener in separate 100 mls. portions of dimethyl formamide. Then ml. of each of the dimethyl forrnamide solutions is added into eight individual dyebaths containing 100 mls. of water and 0.1% of Peregal O (a commercially available ethylene oxide condensation product) as a dispersing agent. Into each of the eight dyebaths a 5 grams swatch of nylon is entered and the material heated to 135-140 F. for 1 hour, after which it is removed, rinsed with water and dried. The brightness of the eight dyed cloths are then read on an ultraviolet fluorescent photometer. The brightness reading of each of the brightener compounds runs on the average between 30 to 43.

Duplicate dimethyl-formamide solutions of each of the brighteners of Examples I to VIII were prepared and applied to Dacron in the same manner as above. High brightness readings are obtained on these also.

EXAMPLE D( filtering, the crude product is purified by dissolving in 500 grams of N,N-dirnethy1formamide containing 5 grams of animal charcoal and filtering at 100 C. The filtrate is then diluted with 2500 grams of water. After filtering and drying, 28.2 grams of 4-chloro-N-[3-(N,N-dimethyl)amino propyl] 4 [2 (ZH-naphtho[1,2]triazolyl)]-stilbenecarbonamide is obtained as a bright yellow powder which melted at 228.l-229.2 C. uncorrected.

The brightener is applied to polyacrylonitrile fiber (Orlon) as follows: 50 mg. of brightener is dissolved in 100 cc. of dimethyl formamide. 5.0 cc. of this solution (=.0025 gram of brightener) is added to a dyebath containing 145 cc. of 1% acetic acid. A 5.0 g. swatch of Orlon is added and the dyebath heated and agitated to 190-200 F. for 1 hour, after which the material is removed, rinsed and dried. The treated cloth is brightened to a high degree in contrast to untreated cloth.

The 4' chloro 4 [2-(2H-naphtho[1,2]triazolyl)]-2- stilbenecarbonyl chloride utilized in this example is prepared by adding 130 grams of 4chloro-4-[2-(2H-naphtho [1,2]triazolyl)]-2-stilbenecarboxylic acid to a mixture of 350 grams of thionyl chloride and 1 gram of pyridine. After stirring for 5 hours at -95 C., the excess thionyl chloride is distilled under reduced pressure and the solid residue of the acid chloride weighs 130 g. and melts at 187.8 190.0 C. uncorrected.

The preparation of 4'-chloro-4-[2-(2H-naphtho[1,2] triazolyl)]-2-stilbenecarboxylic acid is as follows:

To a solution of 159 grams of 4-amino-4'-chloro-2- stilbene-carboxylic acid in 2400 cc. of glacial acetic acid is added 304 cc. of concentrated hydrochloric acid and 1500 cc. of water. The mixture is cooled to 0 C. and a solution of 41 grams of sodium nitrite in cc. of water is added to effect the diazotization. After stirring for 30 minutes at 0 C.-5 C., the excess of nitrous acid is reacted with enough sulfamic acid to give a negative test for nitrite on starch-iodide paper. A warm solution of 92.2 grams of 2-naphthylamine in 1500 cc. of water containing 68 cc. of concentrated hydrochloric acid is added gradually to the diazo solution maintained at 5 to 10 C. The coupling reaction is completed by adding over a period of 1 hour 864 grams of sodium acetate trihydrate followed by stirring of the mixture for 16 hours. The precipitated o-aminoazo dyestufi is separated by suction filtration and washed thoroughly on the funnel with warm (60 C.) water to give 700 grams of wet filter cake.

The entire wet cake of dye is dissolved at 95 C. in 3000 cc. of mixed picolines and treated with a solution of 362 grams cupric sulfate pentahydrate in 725 cc. of water. After stirring the mixture for 2 hours at the refiux temperature, a solution of 116 grams of sodium sulfide flakes in 500 cc. of water is added. The charge is clarified at 90 C. to remove the copper sulfide precipitate. The clear filtrate is treated with aqueous sodium hydroxide solution to pH 10 and then distilled with steam to separate the picoline. The product is filtered from the residue after the steam distillation, slurried in 6000 cc. of water at 90 C. and treated with concentrated hydrochloric acid to Congo blue acidity. After filtering and washing the filter cake free of acid with water, the material is dried at C. under reduced pressure to give 200 grams of 4'-chloro-4- [2-(2H-naphtho[1,2]triazolyl)]-2-stilbenecarboxylic acid, a yellow powder which melted at 274-275.8 C. uncorrected.

The 4-amino-4'-chloro-2-stilbenecarboxylic acid used above is obtained as follows:

A solution of 200 grams of 4'-chloro-4*nitro-2-stilbenecarboxylic acid [prepared from 4-chlorobenzaldehyde and S-nitro-o-toluamide by the method of Macovski, Georgescu and Bachmeyer, Ber., 748, 1279-84 (1941); Chem. Abstracts, 36, 4813 (1942)] in 540 grams of N,N-dimethylformamide is reduced with 200 grams of iron borings etched with 50 grams of concentrated hydrochloric acid in 300 grams of water containing 800 grams of N,N-dimethylformamide.

By employing the reaction conditions given in Example IX, the brightener 2,4-dichloro-N-(3-morpholino)-ethyl- 4 [2I-I-naphtho-[1,2]triazolyl)]-2-stilbenecarbonamide is prepared from 12.8 grams of 2-morpholinoethylamine and 23.9 grams of 2',4-dichloro-4-[Z-(ZH-naphtho[1,2]triazolyl)]-2-stilbenecarbonyl chloride (obtained by condensing 2,4 dichlorobenzaldehyde with -nitro-o-toluamide according to Macovski, Georgescu and Bachmeyer, Ber., 748, 1279-84 (1941); Chem. Abstracts, 36, 4813 (1942) to produce 2',4-dichloro-4nitro-2-stilbenecarboxylic acid (M.P. 256.l259.9 C.) which is then reduced to the amine, diazotized and coupled to 2-naphthylamine, oxidized to the triazole and treated with thionylchloride as shown in Example IX.

The resulting brightener is applied to Orlon in the same manner as in Example IX. The treated cloth has much greater brightness than the untreated cloth.

EXAMPLE XI CHrCH:

CONHCsHrN O CHsC 1 EXAMPLE XII p-Tolualdehyde is condensed with 5-nitro o-toluamide to produce 4'-methyl-4-nitro-2-stilbene-carboxylic acid [(method of Macovski, Georgescu and Bachmeyer, Ber., 74B, 1279-84 (1942); Chem. Abstracts, 36, 4813 (1942 In the manner given in Example DC, the nitrostilbene is reduced, diazotized and coupled to 2-naphthylamine, oxidized with cupric sulfate to form the triazole and finally treated with thionyl chloride which yields 4'-methyl-4-[2- (2H naphtho[1,2]triazolyl)]-2-stilbenecarbony1chloride as a yellow powder.

65 grams of the 4'-methyl-4-[2-(2H-naphtho[1,2] triazolyl)]-2stilbenecarbonyl chloride prepared as above are condensed with 33 grams of diethylamine while following the procedure of Example DC.

The resulting brightener is applied to a polyester fiber (Dacron) as follows: 50 mg. of brightener are dissolved in 100 cc. of dimethyl formamide. 5 cc. of this solution are added to 145 cc. of 0.1% Peregal 0 aqueous solution. Peregal O is a polyoxyethylene condensation sur- 14 factant. A 5.0 gram swatch of Dacron is introduced and the dyebath heated to 190200 F. for 1 hour with agitation. The cloth is removed, rinsed and dried. The treated cloth shows a much greater whiteness than untreated cloth.

EXAMPLE XIII /T N ooNHcHmHmwHm N l By using 39.6 grams of 2-(N,N-dimethylamino)ethyl amine in place of 33 grams of diethylamine in Example XII, the brightener N-[2-(N,N-dimethylamine)]ethyl 4'- methy1-4-[2-(2H naphtho[1,2]triazoly1)]-2-stilbenecarbonamide is prepared.

The brightener is applied on polyacrylonitrile fiber (Orlon) by the method given in Example IX. The treated fabric is much whiter than the untreated Orlon swatch.

EXAMPLE XIV A mixture of 67 grams of 4'-chloro-4-[2-(2H-naphtho [1,2]triazolyl)]-2-stilbenecarbonyl chloride (prepared in Example IX), 78 grams of di-n-butylamine and 800 grams of toluene is allowed to react as described in Example IX to give 46 grams of 4-chloro-N-(di-n-butyl)-4-[2- (2H naphtho[l,2]triazolyl)] Z-stilbenecarbonamide, M.P. 176.2 C.177.1 C. uncorrected.

The brightener is applied on polyamide fiber (nylon) using the method given in Example XII for application of a brightener to polyester (Dacron). The treated nylon swatch appears considerably whiter when compared with the untreated swatch.

EXAMPLE XV omen,

A mixture of 41 grams of 4-[2-(2H-naphtho[1,2] triazolyl)]-2-stilbenecarbonyl chloride, 25 grams of morpholine and 500 grams of toluene is heated for 6 hours at C. After evaporation of the toluene, the residue is washed with water and recrystallized from 200 grams of ethanol to yield 4-[2-(2H-naphtho[1,2] triazolyl)]-2-stilbenecarbonylmorpholine as a yellow powder.

The compound 4-[2-(2H-naphtho[1,2]triazolyl)]-2- stilbenecarbonyl chloride is synthesized according to the procedure described in Example D( for the preparation of 4' ch1oro-4-[2-(2H-naphtho[1,2]triazolyl)]1-2-stilbenecarbonyl chloride starting from 36.4 grams of 4-nitro-2- stilbenecarboxylic acid (obtained from benzaldehyde and the methyl ester of S-nitro-o-toluic acid according to the method of Pfeifier and Matton, Ber. 44, 1119).

The brightener is applied to both polyester (Dacron) and polyamide (nylon) fibers in the manner given in Example XII for the application of a brightener to polyester fiber. In each case, the fabric treated with brightener appears much whiter than the untreated fabric.

1 EXAMPLE Xvr A mixture of 270 grams of 4 methoxybenzaldehyde, 360 grams of S-nitro-o-toluamide and 12 grams of sodium methylate dissolved in 2500 grams of methanol is allowed to react in accordance with the method of Macovski, Georgescu and Bachmeyer, Ber. 74B, 1279-84 (1941) to produce 4-methoxy-4-nitro-2-stilbenecarboxylic acid.

By substituting 187 grams of 4'-methoxy-4-nitro-2-stilbene-carboxylic acid for 200 grams of 4-chlor0-4-nitro- 2-stilbene-carboxylic acid in the reduction step in Example IX, and then continuing as described in Example IX with the diazotization, coupling to Z-naphthylamine, oxidation and subsequent reaction of the triazole compound with thionyl chloride, the 4'-methoxy-4-[2-(2H- naphtho[l,2]triazolyl)] 2 stilbenecarbonyl chloride formed is treated with morpholine in the manner described in Example XV to give the brightener 4'-methoxy- 4 [2 (2H-naphtho[1,2]triazolyl)]-2-stilbenecarbonylmorpholine.

The brightener is applied to both polyamide (nylon) and polyester (Dacron) fibers in the manner referred to in Example XII. The treated nylon and Dacron fabrics are whiter in appearance than the untreated fabrics.

EXAMPLE XVII grams of dimethyl terephthalate, 4.85 grams of ethylene glycol and 0.003 gram of metallic sodium, as a catalyst, are heated for 3 hours at 200 C. in a stream of pure nitrogen. At the end of 3 hours, 0.30 gram of the brightener of Example I are added to the resulting polymer. The low molecular weight polymer is then heated at 280 C. for 30 minutes, then further heated for 10 hours in a vacuum. During the heat conversion a slow current of nitrogen is introduced through a capillary tube. The final product melts at 260 C. The methyl alcohol formed as a by-product of the ester interchange is removed during the heating period. The final product as formed is extruded in molten form as a ribbon cooled with a water spray, then cut into chips. The chips are melted in the absence of air and water, then extruded through orifices to give them the desired shape. The shaped articles can be converted into fibres in continuous filament form or cut into short segments as staple. Both filaments and short segments showed a noticeable whitening effect. The same results are obtained with the brighteners of Examples II to XVI, inclusive.

EXAMPLE XVIII To 10 grams of Dacron polyester cloth in an aqueous bath of 200 mls. volume at 90 C. is added a solution of 0.002 gram of brightener of Example I in 5 mls. of dimethyl-formamide. The polyester cloth in the bath is agitated for 1 hour, after which it is removed from the bath, rinsed with water, and dried. It is then further heated in an oven for 2 hours at 200 C., and then cooled to room temperature. The heat setting at 200 C. causes migration of the brightener into the fiber and produces a whitening effect thereby. The Dacron in this operation is brought to a temperature just below its softening point so that it becomes necessary to adapt the process to the particular polyester at hand. This example illustrates a transition case between a true melt application and the textile applications at lower temperatures.

16 We claim: 1. A fluorescent naphthotriazole compound of the class selected from the group consisting of those of the following formulae:

CONH- a N CON-(R4): N

wherein R and R represent a member selected from the class consisting of hydrogen, halogen, lower alkyl and lower alkoxy, R represents a member selected from the class consisting of hydrogen, lower alkyl, lower hydroxy alkyl, dialkylamino alkyl of from 3 to 16 carbon atoms, morpholinoN-alkyl and piperidino-N-alkyl wherein the alkyl group contains from 1 to 4 carbon atoms, R., represents a member selected from the class consisting of a lower alkyl and lower hydroxy alkyl group, and R represents the atoms necessary to complete with the nitrogen atom a heterocyclic ring system selected from the class consisting of 5- and 6-membered ring system.

2. A compound as defined in claim 1 wherein R is hydrogen.

3. The compound of the formula:

4. The compound of the formula:

5. The compound of the formula:

1 as N/ t? \J 1 7 6. The compound of the formula:

N CH,@CH=CH N ONE, N

7. The compound of the formula:

@CHH N/T 8. The compound of the formula:

-CH I N G 9. The compound of the formula:

C1 CH=CH N CHr-CH:

CONH(CH:)N /O CHz-CH:

18 10. The compound of the formula:

CHI-CH, 0 ON 0 CHg-Cflz 11. The compound of the formula:

W CMH NQ 12. The compound of the formula:

J] ON (lb-C 119): N I

References Cited UNITED STATES PATENTS JOHN D. RANDOLPH, Primary Examiner.

WALTER A. MODANCE, Examiner.

Claims (1)

1. A FLUORESCENT NAPTHOTRIAZOLE COMPOUND OF THE CLASS SELECTED FROM THE GROUP CONSISTING OF THOSE OF THE FOLLOWING FORMULAE: