US3080233A - Method of incorporating metal salts of color couplers in photographic emulsions - Google Patents

Description

United States Patent Ofitice 3,080,233 Patients;d Mar. 5, 1963 Curt B. Roth and Fritz W. H. Mueller, Einghamton,

N .Y., asisguors to Generai Anilinedz Film Corporation, New York, N.Y., a corporation er Delaware I No Drawing. Filed Apr. 3%), 1959, filer. 809326 This invention relates to color photography and in particular to photographic emulsions for color photography containing the alkali metal salts of color formers or couplers incorporated therein by means of Water miscible solvents.

Photographic emulsions are described containing thereina coupler compound of the type capable of coupling with the oxidation products of a primary aromatic amino developing agent whereby is produced a colored photographic image. In the manufacture of such emulsions, there are a variety of Ways in which the coupler compounds can be incorporated therein. In one preferred method, an aqueous solution of the coupler compound is dissolved directly in the hydrophilic colloid of the photographic emulsion. Such couplers commonly contain, in addition to a non-difiusing group, a sulfonic acid or carboxylic acid grouping and are employed in the form of their alkali metal salts. I

However, there are certain dililculties which are frequently encountered in carrying out the aforesaid procedures. Thus, certain of the above couplers are soluble only in highly alkaline solutions which are too basic for incorporation in conventional light sensitive silver halide emulsions.

Another difficulty attendant to the use of couplers of this type can be attributed to the presence of the non-diffusing group. The presence of this long aliphatic chain, in combination with a salt-forming group in the coupler molecule, customarily increases the viscosity of the photographic emulsion resulting in coating difficulties.

It is, therefore, an object of the present invention to provide a novel means of incorporating the alkali metal or ammonium salts of colored or colorless couplers containing acidic groups in photographic emulsions.

It is a further object to provide a method of incorf porating the alkali metal salts of couplers containing acid groups in photographic emulsions without increasing the viscosity of said emulsions.

It is a still further object to provide a method of incorporating the alkali metal and ammonium salts of such couplers without resorting to conditions of high basicity or alkalinity.

Other objects will appear hereinafter as the description of our invention proceeds.

The aforesaid objects can be accomplished by dissolving a color coupler of the type described herein in the form of its alkali metal salt in a water soluble or water miscible solvent for said alkali metal coupler salt and dispersing the resulting solvent solution of the coupler salt in a photographic colloid. The Water soluble or Water miscible solvent is then removed from the alkali metal coupler salt dispersion incorporated in a hydrophilic colloid silver halide emulsion.

The dispersions of the alkali metal coupler salts obtained as described above consist of extremely finely divided particles which display no tendency to settle out or coalesce. Such dispersions of alkali metal coupler salts can be stored indefinitely in the chilled state prior to the coating operation.

As previously pointed out, the couplers used in our process are characterized by the presence of a salt-form- 2 ing group, i.e., a carboxylic acid or sulfonic acid group, and a non-difiusing group such as an aliphatic chain of at least 10 carbon atoms. Such couplers are further characterized in that their alkali metal salts are not sufficiently soluble in aqueous systems or require prohibitively high pH values in order to eifect their incorporation directly in a hydrophilic photographic colloid. Couplers which we have found particularly suitable in this connection contain, as the non-diffusing group, an alkyl radical of at least 10 carbon atoms in which a salt-forming radical is located on the terminal carbon atom of said alkyl group. These couplers can be depicted by the following general formula:

CO-NHR wherein M represents a hydrogen, ammonium or an alkali metal, R represents a coupler molecule of the type containing a reactive methylene or phenolic hydroxy group, andn n represents a positive integer of 9 or more.

By reactive methylene group is meant the type commonly encountered incolor couplers and which can be depicted by the following general formula:

wherein X arid Y stand for electron attracting groups such as carbonyl, cyano, nitr'o and the like. By'pheriolic hydroir'y group is meant the phenolic phe'uyl' gfeu' 's commonly understood in the color coupler art and includes the phenolic or hydroXy naphtho'ic types having [a rea'c tive position para to the said hydroxy group, that is, a position which is unsubstituted or which is substituted with a replaceable group. The aforesaid groups are well recognized in the photographic fild so that further discussion of such entities would be superfluous.

Structures falling within the ambit of the above general formula include the following:

COMPOUND 1 o ON'H Q COMPOUND 4 assassa COMPOUND NZISOMOHsMoCONH CONHfil-CH3 COMPOUND 6 NQSO3(CH2)1QCONH-C-CH2 COMPOUND 7 ,-oocnzooi\rn@ NHCO- -NHCO(CH2)10SO3N3 The couplers depicted formulistically above, when incorporated in a photographic emulsion and according to the method described herein, yield, on color development, exceedingly fine-grain and stable dye images and are thus valuable in the art of color photography.

Other couplers of the general type, whose alkali metal salts are insoluble or require excessively high alkalinity to incorporate them in a photographic emulsion, lend themselves to our process.

According to the present invention, a photographic emulsion is prepared for coating by adding a solution of the alkali metal salt of the coupler in a water soluble solvent directly to a melted gelatino silver halide emulsion under efiicient agitation with a laboratory type mixer such as a Waring Blendor.

It has been our experience, however, that superior results ensue when a solution of the alkali metal salt of the color former in a water miscible solvent is first added to a gelatin solution with eificient agitation and the resultant mbrture then combined in a second operation with the melted gelatino silver halide emulsion. The latter method is advantageous because it avoids excessively strong agitation of the light sensitive silver halide emulsion which can cause fog. The dispersions of the alkali metal salts of the couplers in gelatin may thus be combined with the melted gelatino silver halide emulsion using gent-1e mixing.

In one procedure, the color former is first dissolved in a water miscible solvent such as dimethylformamide and this solution is added to an aqueous gelatin solution under vigorous agitation. The thusly obtained mixture is then chilled, noodled and washed after which it is com bined with a liquified photographic gelatino silver halide emulsion. The sensitive emulsion is coated after the addition of the customary stabilizers, preservatives and spreading agents in the usual manner on a conventional film base of the type commonly employed in the art such as cellulose acetate, polyester, i.e., polyethyleneterephthalate, polycarbonte, polyamide or paper, glass or the like.

In some instances, it may be desirable to remove the solvent by evaporation rather than washing of the noodled emulsion. This is elfected by coating the aforesaid photographic gelatino silver halide emulsion containing the alkali metal salt solvent solution of the coupler and allowing the solvent to escape by evaporation during the drying of the coated photographic emulsion. If the latter operation is followed, a film base should be selected of a type which is not deleteriously eitected by the action of the water miscible solvents used to dissolve the alkali meta-l salt of the coupler. In this connection, we have found that polyester or polycarbonate film base as well as paper or glass are suitable.

The photographic coatings prepared according to the process described herein produce, on color development, very sharp colored images and display no undesirable side effects such as desensitization or fogging during storage or processing. It is not known, at the present time, if the alkali metal salt of the color former, when in corporated in a hydrophilic colloid in accordance with our invention, represents a true solution or is in such a state of fine division as to constitute a colloidal dispersion or, perhaps, a superfine dispersion. Examples of the Washed emulsions have been examined under the microscope at high magnification, i.e., in the neighborhood of 900 diameters, and there was no evidence to indicate the presence of discrete coupler particles. The extremely fine state of division of the alkali metal salt couplers is borne out by the virtually grainless dye images which they yield upon color development, that is, no dye clumps can be discerned when the developed images are subjected to microscopic examination.

As stated above, the alkali metal and ammonium salts of color formers of the type contemplated herein are either insoluble in a photographic colloid emulsion or require excessively high alkalinity in order to efiect their dissolution in this type of medium. Neither can such color-forming components be incorporated in a photographic emulsion by the well known lip-ophilic dispersion techniques since these coupler salts are too insoluble in the water immiscible oils commonly used for such lipophilic dispersion procedures. Thus, the method disclosed herein offers the sole means of utilizing valuable colorforming components, i.e., the aforesaid alkali metal or ammonium salts, which cannot be incorporated in a photographic emulsion by methods presently known to the art.

As previously pointed out, the photographic emulsions containing metal salts of color former can be prepared by two general methods. In the first of these methods, a di alkylformamide solution such as a dimethylformamide solution of the color former is added directly to a melted gelatino silver halide emulsion While stirring with a laboratory type mixer such as, for instance, a Waring Blendor. In the second of these methods, the solution of color former in dialkylformamide is first dissolved in an aqueous solution of a hydrophilic colloid such as gelatin and the resultant mixture combined with a melted gelatino silver halide emulsion.

The above methods produce an even distribution of color former in the colloid carrier of the light sensitive photographic emulsion unassociated with any photographically inert material, particularly oily dispersants. That such a result should be obtained is rather startling since it has been our experience that attempts to mix solutions of chemical compounds in photographic hydrophilic colloids, wherein the solvent is water soluble, causes a precipitation of the compounds and/ or a coagulation of the colloid by the solvent.

In our preferred method, the color former is first dissolved in dimethylformarnide and this solution is added to an aqueous gelatin solution and thoroughly agitated in a laboratory type mixer or stirrer. The resulting mixture is washed and then combined with a photographic gelatino silver halide emulsion, chilled and the sensitive emulsion then coated in the usual manner on a conventional base such as that of cellulose acetate, polyester, i.e. polyethyleneterephthalate, polycarbonate, polyamide or paper, glass or the like.

In some instances, it may be desirable to remove the dimethylformamide by evaporation rather than by washing or" the noodled emulsion. This is efiected by coating the photographic gelatino silver halide emulsion containing thecoupler as prepared above and allowing the di- -An even more surprising feature of our procedure-concerns the manner by which the dialkylformaim'de solution of the color former blends or mingles with the hydrophilic photographic colloid. It was to be expected that the dialkylformamide solution would be dispersed or emulsified when agitated with the hydrophilic colloid. However, examination with high power optical equipment fails to reveal the presence of discrete particles of the color former dispersed throughout the continuous phase of the hydrophilic colloid. In fact, the aforesaid dialkylformamide solutions actually appear to dissolve in the hydrophilic colloid so that in elfect one obtains a solution of the color former salt in the hydrophilic colloid. As a consequence, a virtually grainless dye image results upon color development.

Photographic films prepared in accordance with the present invention are, when wet, not very hazy or frosty in appearance, a property characteristic of fihns using dispersion methods of the prior or present art.

The following are examples of the methods used by us in incorporating our novel color formers in photographic emulsions. The examples are given by way of illustration only and are not to be construed as limiting the invention.

Example 1 This example illustrates the method used by us in incorporating a cyan color former in a photographic emulsion. The particular color former used in this example has the formula:

(Compound 2) 2.00 grams of the above cyan color former were dis solved in 20 m1. of dimethylformamide. This solution was filtered and the filtrate then mixed into 50 ml. of a 6% aqueous gelatin solution with good stirring. A speed .mixer (Waring Blender, kitchen type) is desirable, al-

.resulting dye in the gelatin resulting in greater sharpness, acutance and resolution.

Example 2 720 milligrams of color former from Example 1 were dissolved in 7 ml. of dimethylformamide, 4 drops of Tergitol NPX added and the mixture filtered. Separately, a 10% aqueous solution of an inert gelatin in water was prepared at 55 C. To 30 ml. of this 10% gelatin solution were added 4 drops of Tergitol #4. The solution was placed into a speed mixer (Waring Blendor, kitchen type). After 30 seconds at full speed, the filtered dimethylforrnamide solution was slowly added over a period of 30 seconds with the mixer running at 30 volts. After the two solutions were combined, the mixer was run at full speed for 60 seconds. The milky-looking product can be used as is or the dimethylformamide can be washed out. 'To wash the dimethylformamide out,"the emulsion was chilled, shredded and then washed by downward replacement washing for 6 hours'with cold water (8 C.). The washed product was then mixed into a photographic emulsion and evaluated as in'Examp'le 1.

Examples 3 and 4 'Thesameprocedure was followed as in Example2 but the amount of dimethylformamide used was dilferent.

Example 3 4 ml. of dimethylformarnide. Example 4 '10 m1. of dimethylformamide.

Examples 5, '6 and 7 Three emulsionswere prepared containing the following ingredients:

14.4 grams of the coupler component were dissolved in -ml. of dimethylformamide, 10 drops of Terg'itol NPX added and the solution filtered. 'To a solution of 576 ml. of 10% gelatin were added 10 drops of Tergitol #4 and the solution placed into a speed mixer. The mixer was now run at 10 volts for 45 seconds. Over a period of 120 seconds, the filtered dimethylformamide solution was then added, the mixer running at 15 volts. After the two were combined, the mixer was run seconds at full speed volts). The warm, milky emulsion was next poured into an 11 inch x 14 inch photographic tray. After cooling, the emulsion was cut up and the noodles placed into a wire basket and washed with'cold (842 C.) running water until the noodles were washed free of dimethylformamide (about 8 hours).

The use of Tergitol produces a finer dispersion of color former and dye in the gelatin. Note that no alkali was used in these examples. The use of alkali produces a yellowish looking product and is detrimental as a-rule.

The washed noodles were then added to a photographic color emulsion and coated. Samples of coatings containing the dyes developed by the use of the novel color former components as in the above examples were then evaluated by exposing them to light and to high humidity Example 8 This example illustrates the incorporation of a magenta color former in a photographic emulsion. The particular color former used in this case has the formula:

(Compound 4*) aosaoss Into a Monel metal mixer vessel on a Waring Blendor (kitchen type) were poured 30 ml. of a 10% aqueous gelatin solution. The mixer was started at 30 volts and over a period of seconds were then added 4 drops of Tergitol #4. The mixer'was run for seconds at 30 volts. Into this homogeneous white emulsion was added slowly through a special funnel (containing a built-in filter and a fine tip), over a period of 30 seconds with the mixer running at 30 volts, a solution consisting of 720 mg. of the above color former in 7 ml. of dimethylformamide and 4 drops of Tergitol NPX. The mixer was then run for 30 seconds at 120 volts. Then, 4 drops of a aqueous solution of sodium hydroxide were added over a period of 5 seconds with the mixer running at 90 volts. Mixing was continued for seconds at 90 volts. The clear yellow product was transferred into a tray and allowed to cool. The chilled gelatinous product was cut into small noodles which were Washed for 18 hours with cold water (8-l2 C.). The washed noodles were then remelted at 40 C. and added to 50 g. of photographic emulsion containing O.6 ml. of an 8% aqueous solution of saponin as a spreading agent. Other adjuncts such as sensitizing dyes, stabilizers, etc., may be added at this point. The 40 C. warm mixture was then coated onto a film support.

Samples of coatings containing the dye formed by color development using the color former of this example were then exposed to light and high humidity conditions together with samples of dyes developed by the use of prior art color formers of the type having saltforming groups. Such prior art color formers used in this test are those disclosed in U.S.P. 2,200,306. The

results obtained from this test are shown in the follow- As can be seen from the above data, our color former yields a dye image which is superior in overall stability to a similarly produced dye image from a coupler of the above prior art patent.

Example 9 The magenta color former of the following formula was used in this example.

(Compound 6) into a Monel metal mixing vessel on a speed mixer (Waring Blendor, kitchen type) were placed ml. of a 10% aqueous gelatin solution of 40 C. With the mixer running at volts, 4 drops of Tergitol #4 were added to the gelatin over a period of 5 seconds. The mixer was then run for 10 seconds at 35 volts. To this homogeneous mixture was then added, by means of a special funnel, a solution of 720 mg. of the above coupler in 7 ml. of dimethylformamide and 4 drops of Tergitol NPX. The addition was made over a period of 30 seconds with the mixer running at volts. The mixer was then run for 30 seconds at 120 volts. The product was poured into a 8 tray and allowed to cool to room temperature. After chilling, the product was cut into small noodles with a knife. These noodles were then washed for 18 hours with cold (812 C.) water. After draining of the excess water, the noodles were remelted at 40 C. and added in darkness to 50 g. of a color type photographic emulsion. This emulsion contained 0.6 ml. of an 8% aqueous solution of saponin besides the usual adjuncts such as sensitizing dyes, stabilizers, etc. The final mixture was coated at 40 C. onto a photographic film support as is customary inthe art.

Example 10 This example illustrates a method of incorporating a yellow color former in a photographic emulsion. The color former used in this example has the formula:

oo Cameron-Q NHC o- Nnco om) ms 031%.

(Compound 7) Into a Monel metal mixer vessel on a speed mixer (Waring Blender, kitchen type) were placed 30 ml. of a 15% aqueous gelatin emulsion. The mixer was started at 30 volts and over a period of 5 seconds were then added 2 drops of Pluronic L-61. The mixer was run for 10 seconds at 30 volts. Then, 4 drops of Tergitol #4 were added over a period of 5 seconds with the mixer running at 30 volts. Mixing was continued for 10 seconds at 30 volts. A solution consisting of 720 of the above color former in 29 ml. of dimethylformamide, 4 drops of Tergitol NPX, 5 ml. of water and 6 drops of a 20% aqueous sodium hydroxide solution was then added through a special glass funnel. This special funnel consisted of a Pyrex glass funnel of 39 mm. diameter whose stem had been drawn out to a small opening of 1 mm. diameter. Into the stem was packed some cotton to filter out mechanical impurities and to regulate the flowing time. The addition was made over a period of 360 seconds with the mixer running at 30 volts. Mixing was continued for 30 seconds with the mixer running at volts. The yellow, slightly opaque product was then poured into a dish and allowed to cool. The chilled product was then cut into small noodles and washed for 48 hours with slow-running cold (812 C.) water. The noodles were then remelted and added to 50 g. of a photographic emulsion. This emulsion had been designed for the yellow layer and contained, besides the usual finals, 1.0 ml of an aqueous 8% saponin solution and 2 drops of Pluronic lr61. The mixture was then coated onto a film base as is customary in the art.

Although, in Examples 1 to 9, we have indicated the use of the customary gelatino silver halide emulsion, other water soluble colloidal materials suitable for preparing photographic emulsions such a polyvinyl alcohol and casein, for example, can be used.

in the foregoing examples, we have referred to certain materials by their common trade names such as Tergitol NPX, Tergitol #4 and Pluronic L-61. The identification of these materials is as follows:

Tergitol NPX is alkylphenyl polyethylene glycol ether and is sold by the Carbide and Carbon Chemical Company, 30 E. 42nd Street, New York 17, New York.

Tergitol #4 is sodium tetradecyl sulfate and is sold as a 25% solution by the Carbide and Carbon Chemical Company, 30 E. 42nd Street, New York 17, New York.

Pluronic L-61 is a polymer prepared by adding propylene oxide to the two hydroxyl groups or" a propylene glycol nucleus until the desired molecular weight is achieved. Ethylene oxide is then added to both ends of the above polymer until the desired ratio of polyoxyethylene to polyoxypro-pylene units is obtained. Pluronic L-61 is composed of a polyoxypropylene fragment with a molecular weight of 1750 while 10% of the total molecular weight "abscess G. 2-arnino-5-diethylamino toluene HCI 2 Sodium sulfite, anhydrous '2 Sodium carbonate, monohydrate, '2 Potassium bromide 2 Sodiumhydroxide to give .pH 10.8. Water to 1 liter.

PREPARATION OF COMPOUNDS In the synthesis of Compound 1 above, the following reactions take place:

I alol NH:

s. melt;

iron reduction O O N H- potassium hydrogen ll-sulbundecanoate C O NH-v phosphor trichloride -o oNH- NHCO(CHa)1uSOsNa Reaction A was carried out in the following manner:

Apparatus1-liter round bottom flask, metal bath.

250 grams of phenyl-l-hydroxy-Z-naphthoate (0.95 M) and 119 g. of m-nitroaniline (0.86 M) were heated for 2 hours at 150 C., 1 hour at 170 C. in a metal bath (bath temp). During the last hour, the phenol was distilled oii at -10 mm. Hg. The cooled melt was ground with methanol in a mechanic blender, filtered on a Buchner funnel, and washed on the funnel with methanol until the washings were nearly colorless. It was recrystallized from dimethylformamide containing some methanol.

Yield: 204 g. yellow needles=74%; M.P. 253 C.

Calc.: C, 66.04; H, 4.17. Found: C, 66.14; H, 4.32.

Reaction B was then carried out as follows:

Apparatus3-neck round bottom flask, stirrer, condenser and electric heatingrnantle.

200 grams of iron powder (40 mesh), ml. of hydrochloric acid, 70 ml. of water and 430 ml. of ethanol were combined in that order and then 30 g. (0.1 M) of the amide produced in reaction A was slowly added to the refluxing mixture. The addition oi the amide required 2 to 4 hours; an excess oi Fe++ has to be maintained during the addition.

The mixture was refluxed overnight and then rendered alkaline against phenolphthalein with 40% aqueous sodium hydroxide. The solution was filtered through a Buckner funner and the filtrate acidified with glacial acetic acid. The resulting precipitate was filtered ofi after coolmg.

Yield: 20 g. light red needles:74%; M.P. 196-197 C. An analytical sample was prepared by recrystallization from acetone/ water.

1VLW. 278.29.

Cale; C, 73.36; 5.07. Found: C, -73.28; H, 5.57.

The final Compound 1 was produced by reaction C as follows:

Appar atus 500 rnl. 3-neck round bottom flask, stirrer, Dean Stark moisture trap, condenser, calcium chloridedrying tube and dropping funnel. 19 grams amine produced in reaction B (0.066 M).

22 grams of potassium hydrogen ll-sulfoundecanoate (1.1X0.066 M), 66 ml. of dry pyridine and 260 ml. of dry benzene were combined in the flask and refluxed by means of an electric heating mantle until all traces of water were removed (req. about .2 hours). The Dean- Stark moisture trap was then removed and the condenser exchanged fora dry one. The mixture was cooled in an ice water bath and, with rapid stirring, a solution of 6.6 m1. of phosphor trichloride in 50 ml. of dry benzene Was added. The addition was made dropwise and required about 1 hour. The mixture was then refluxed on a steam bath for 2 hours. A solution of 9 g. of sodium hydroxide-and 20 g. of anhydrous sodium acetate in 60 ml. of water was added slowly and the mixture cooled in ice. The precipitate was filtered on a Buchner funnel and the last traces of pyridine removed in vacuo. The so obtained 52 g. of yellow powderous material was recrystallized from acetic acid. It was then recrystallized 2 times more from the same solvent.

Yield: 16.4 g.=45%; M.P. 284-285 C.

Cale: C, 60.31; H, 6.14; S, 5.75; N, 5.02. Found: C, 60.41; H, 6.33; S, 5.74; N, 5.01.

The series of reactions for the preparation of Compound 2 may lie-represented vas follows:

(A) on salol melt ,-coo N1; N0:

I f o o NH-.- -No| G1 a on iron reducticn C ONH\ \/,"NH'

ooNH-. -Nm ooomomnosoma 0 ONHe-QNHCO cm) 108 OaNa REACTION A 1 mole (172.58 g.) of 2-chloro-4-nitro aniline and 1.1

mole (264.28 g.) of phenyl-l-hydroxy-Z-naphthoate were combined together in an open l-liter, l-neck round bottom flask and the mixture was heated without stirring for 3 hours in a metal bath at 155-160 C. The flask was then connected to an oil pump vacuum and the phenol distilled ed at a bath temperature of 160 C. The cold melt was then crushed and transferred to a speed mixer (Waring Blender, kitchen type). After the addition of 500 ml. of cold methanol, the mixer was run at full speed (120 volts) for about 5 minutes. The fine suspension was then filtered by means of a Buchner funnel and the product was washed on the funnel with methanol until the filtrate was colorless (1500 ml. of methanol). After crystal lizing the solid once from chlorobenzene, it was filtered, sucked dry by means of an aspirator, washed again in small portions with a total of 1500 ml. of methanol, and used directly for the next reaction after letting it dry overnight at room temperature.

REACTION B 45 grams of iron powder (40 mesh) and 15 ml. of concentrated hydrochloric acid were mixed into a 3-neck, 1- liter round bottom flask provided with a stirrer and a reflux condenser. After 5 minutes, 100 ml. of water and 400 ml. of ethanol were added and the mixture heated to reflux temperature with vigorous mechanical stirring. 32 grams (about 0.1 mole) of the previously prepared airdried and powdered nitro compound was then slowly added to the stirred, boiling reducing mixture over a period of 1 hour. The suspension was then refluxed, with efficient stirring, for 18 hours. The aqueous phase was made alkaline with aqueous, 6 N sodium hydroxide solution. After filtering from the iron-mud by means of a Buchner funnel and Filter-Col (manufactured by Johns- Manville), the filtrate was acidified with. glacial acetic acid. After cooling, the crystalline product was filtered and then recrystallized once from acetone. The product was air-dried and exhibited a melting point of 210 C.

REACTION C 21 grams (0.066 mole) of the above amine, 22 g. of ll-potassium sulfoundecanoic acid, 66 ml. of anhydrous pyridine and 260 ml. of dry benzene were refluxed for 2 hours under a Dean-Stark moisture trap. The flask was then cooled to C. and to the cold, stirred solution was slowly and carefully added dropwise a solution of 6.6 ml. of phosphor trichloride (PCl in 50 ml. of dry benzene over a period of 1 hour. The temperature during this addition was carefully kept below C. After the addition was complete, the mixture was heated to reflux temperature and then refluxed for 2 hours with stirring. To the hot solution was then slowly added a solution containing 9 g. of sodium hydroxide and 20 g. of anhydrous sodium acetate in 50 ml. of water. The rate of addition depended on the speed of refluxing caused by this exothermic reaction. After the addition was complete, which took about 5 minutes, the mixture was cooled to room temperature and the solid filtered through a Buchner funnel. The yellowish raw-product was freed from traces of pyridine and water by placing it into a desiccator over concentrated sulfuric acid. The product was finely powdered and then recrystallized from 80% aqueous acetic acid. After two recrystallizations, the product was white and exhibited a decomposition point at 287 C. Further recrystallizations did not raise the decomposition point. The yield was 27 g. V

The ll-potassium sulfoundecanoic acid or potassium hydrogen ll-sulfoundecanoate (J. Chem. Soc, 1956, p. 2560),

?0 OH sho OaNB.

used in this and the other examples was prepared as follows:

Into a 5-liter, .B-neck round bottom flask provided with stirrer and reflux condenser was charged 91 g. (0.5 mole) of undecanoic acid,

COOH

315 g. of sodium sulfite heptahydrate (Na SO -7H O), 600 ml. of ethanol and 300 ml. of water. The mixture was refluxed for 1 hour with stirring, at which time a clear solution was obtained. To the hot, stirred solution was then added, in one portion, 500 g. of anhydrous potassium chloride. The slurry was then cooled to 25 C. and allowed to stand for 1 hour and then filtered through a B-uchner funnel. The solid was washed, on the funnel, with 200 ml. of an aqueous, 5% potassium chloride solution, then with 200 ml. of methanol and 200 ml. of ether. The washed product was recrystallized once with a solution containing 400 ml. of concentrated hydrochloric acid, 400 ml. of water and 40 g. of potassium chloride. The crystalline material was filtered again by means of a Buchner funnel and washed on the funnel with the following solvents: Twice with ml. each, of ice water, twice with 100 ml, each, of methanol and twice with 100 ml., each, of et er. Yields of various batches: 117 g., 119 g. and 128 g.; melting point 193-197 C. The melting point range of the analytical sample was 195-197" C.

The preparation of Compound 3 may be represented as follows:

REACTION A OH COOMe 0H OOOMe CONH 76 grams of 3-amino-5-nitromethylbenzoate (0.39 mole) and 114 g. of 1-hydroxy-2-phenyl naphthoate (1.1 0.39 mole) were charged into a 500 ml. round bottom flask. The mixture was heated over a period of 2 hours to 155160 C. and then kept for 2 hours at 160 C. During the last 2 hours, vacuum was applied to the flask (5-10 min/Hg.) to remove the phenol. The material was then cooled, ground with 200 ml. of methanol in a mechanical blender, filtered through a Buchner funnel and washed on the funnel until the washings were nearly colorless. The crude product was recrystallized from dimcthylforrnamide and methanol. Yield: g. 87% (calculated on ester); M.P. 255256 C. Anal. sample M.P. 256257 C.

C19I I14N206:366.32.

Cale: C, 62.29; H, 3.85; N, 7.65. Found: C, 62.27; H, 3.92; N, 7.58.

REACTION B (13H 0 O OMe OONH- OH COOMe CONH- I NH:

125 grams of the above nitro compound (0.34 M), g. of iron-filings (40 mesh), 45 ml. of hydrochloric acid, 1400 ml. of ethanol and 250 m1. of water were charged into a 3-liter round bottom flask equipped with a stirrer and a reflux condenser. The nitro compound produced by reaction A was added in small portions to the refluxing mixture so that an excess of Fe++ was maintained. After the addition was complete (requires about '3 'hours), the mixture was kept refluxing for another 15 hours. The mixture was then filtered, the filter cake extracted with boiling dimethylformamide and this extract combined with the filtrate which was diluted With water until the compound precipitated. Further precipitation was completed by cooling in ice. The solid was filtered off by means of a Buchner funnel, washed on the funnel with methanol until washings were nearly colorless and recrystallized from acetone. Yield: 65 g.; M.P. 240-241 C.

REACTION o H0O C (CH2) NSOSNB 50 grams of the above amine (0.165 mole), 55 g. of 11-potassium sulfoundecanoic acid, 165 ml. of dry pyridine and 650 ml. of dry benzene were charged in a 2- liter, 3-neck round bottom flask equipped with stirrer, Dean-Stark moisture trap, reflux condenser, calcium chloride tube and a dropping funnel. The mixture was refluxed until all traces of water had been removed (requires about 2 hours). The mixture was cooled with ice water and a solution of 16.5 ml. of phosphor trichloride in 50 ml. of dry benzene was added dropwise under rapid stirring (requires about 1 hour), followed by refluxing for 2 hours on a 'steam bath. To the hot solution was added a solution of 30 g. of sodium hydroxide and 35 g. of anhydrous sodium acetate in 200 ml. of water and the reaction cooled to 0 C. in a refrigerator for 15 hours. The solid was filtered and dried over sulfuric acid in a vacuum desiccator and recrystallized from 80% acetic acid and then 3 times from 70% methanol. Yield 50 g.

Cale: C, 57.03; H, 5.61; S, 5.25; N, 4.59. Found: C, 57.12; H, 6 .16; S, 5.14; N, 4.54.

The preparation of compound 4 may be represented as follows:

REACTION A 176 grams of 3-amino-l-phenylpyrazolone-S (1 mole) were slurried in a 2-liter round bottom flask With 600 ml. dry pyridine. To this was added a slurry of 186 g. of m-nitrobenzoylchloride (1 mole) in 200 ml. 'of dry benzene. After the main reaction has subsided, the mixture was heated on a steam bath for hours and then poured in 2-liters of ice water, filtered and recrystallized from dimethylformamide and methanol.

The product obtained was:

53% yield 174 g.; M.P. 226-227 C.; Anal. sample Ml. 227-228 C.

Calc.: C, 59.08; H, 4.027; N, 17.22. Found: C, 59.74; H, 4.30; N, 17.22.

14 REACTION B 400 grams of iron powder (40 mesh), 135 ml. of hydrochloric acid, 800 ml. of water and 3200- rnl. of ethanol were combined in .this order in a 5-liter, 3-neck flask equipped with stirrer and reflux condenser. After the mixture started refluxing, 174 g. of the compound (0.535 mole) (from reaction A) was added in small portions, always maintaining an excess of Fe++. Thisrequired about 3-4 hours. The mixture was kept refluxing for 15 hours, then made basic with 50% sodium hydroxide (phenolphthalein as indicator). It was filtered .by means of a Buchner funnel, the filtrate acidified with glacial acetic acid and cooled. The crystalline precipitate was filtered off and washed once with methanol. 73% yield 117 g.; MP. 225226'C. Anal. sample M1. 227- 228 C.

The product obtained was:

CONHCCH2 C H N O =2953L Cale: C, 65.08; H, 5.12; N, 18.97. Found: C, 65.33; H, 6.77; N, 18.81.

REACTION C 117 grams of the above amine (0.395 mole), 130 g. of potassium hydrogen ll-sulfoundecanoate (1.l 0.395 mole), 395 ml. of dry pyridine and 1500 ml. of dry benzene were charged in a 3- neck, 3-liter round bottom flask equipped with stirrer, Dean-Stark moisture trap, dropping funnel, condenser, and a calcium chloride drying tube. The mixture was refluxed until all traces of water were removed (about 2 hours). After cooling the flask in ice water with rapid stirrin a solution of 18 ml. of phosphor trich loride (PCI in 200 ml. of dry benzene was added dropwise over a period of 1 hour and then kept at reflux temperature on a steam bath for 2 hours. To the hot mixture was added a solution of 31 g. of sodium'hydroxide and g. of anhydrous sodium acetate in 200 m1. of water. The flask was then cooled to 0 C. and kept in a refrigerator for 15 hours. The resulting solid was filtered'by means of a Buchner funnel and dried in a vacuum desiccator over sulfuric acid. It was once recrystallized from acetic acid and then twice from 70% methanol. Yield g.

The product obtained Was:

CONHGCH1 SOaNa(CHz) 106 ()NH (Compound 4) spouses 40 ml. of dry benzene added dropwise with rapid stirring. This required about 1 hour. The mixture was refluxed for 2 hours on a steam bath and to the still hot mixture was added a solution of 4.5 g. of sodium hydroxide and 11 g. of sodium acetate (anhydrous) in 40 ml. of water. The mixture was then cooled, filtered and dried in a vacuum desiccator over concentrated sulfuric acid. The product was purified by dissolving it in 250 ml. of hot 70% methanol which had previously been adjusted to a pH of 9 with 2 N sodium hydroxide and precipitating it with 5 N hydrochloric acid after filtration.

The above 3-(rn-aminobenzamido)-l-(2,4,6 -tricl1lorophenyDpyrazolone-S was obtained by the acylation of 3- amino-1-(2,4,6-trichlorophenyl)pyrazolone-S with m-nitrobenzoyl halide in pyridine solvent. The resulting 3- (m-nitrobenzamido)pyrazolone-S was then reduced to the corresponding amino compound by catalytic hydrogenation using Raney nickel as a catalyst.

The preparation of Compound 6 may be represented as follows:

18 grams of 3-amino-l-phenylpyrazolone-S, 31 g. of potassium hydrogen ll-sulfoundecanoate, 60 ml. of dry pyridine and 260 ml. of dry benzene were charged in a l-liter, 3-neck round bottom flask equipped with stirrer, Dean-Stark moisture trap, dropping funnel, condenser and calcium chloride tubing. The mixture was refluxed until all traces of water were removed, then cooled in an ice water bath and a solution of 4.5 ml. of phosphor trichloride in 50 m1. of dry benzene was slowly added. This addition was made dropwise and required about 1 hour. The mixture was refluxed for 2 hours on a steam bath and a solution of 8 g. of sodium hydroxide and 21 g. of anhydrous sodium acetate in 50 ml. of water was added to the hot mixture. The flask was stored in a refrigerator for hours and the contents then filtered on a Buchner funnel and dried in a vacuum desiccator over sulfuric acid. Recrystallization from three times 80% acetic acid. Yield 23 g. of purified product.

02110.: C, 53.92; H, 6.34; N, 9.43; S, 7.19. Found: C, 54.75; H, 8.04; N, 9.59; S, 6.74.

The preparation of Compound 7 may be represented as follows:

REACTION A 96 grams of 1-amino-a-benzoylacetanilide were slur-tied in 200 ml. of dry benzene and a slurry of 71 g. of p-nitrobenzoylchloride in 400 ml. of pyridine was added. The mixture was heated for 5 hours on a steam bath, then the pyridine removed by vacuum distillation. The residue was recrystallized from a mixture of dimethylformamide and methanol.

The compound produced was:

Yield 170 'g.; MP. 258259 C.

Cale; C, 65.34; H, 4.23; N, 10.39. Found: C, 65.73; H, 4.26; N, 10.63.

REACTION B 300 grams of iron powder (40 mesh), 160 ml. of hydrochloric acid, 400 ml. of water and 2000 ml. of ethanol were charged in a 3-liter, 3-neck round bottom flask equipped with stirrer and reflux condenser. To the refluxing mixture, 170 g. of the above nitro compound from reaction A was added in small portions, always maintaining an excess of Fe++. The mixture was refluxed overnight, rendered alkaline against phenolphthalein with 50% sodium hydroxide, filtered and acidified with dry acetic acid. The nearly white precipitate was filtered ofii.

The compound produced was:

Yield 50 g.; M.P. 238241 C. (32110.: C, 70.77; H, 5.13; N, 11.26. Found: C, 70.3; H, 5.14; N, 11.98.

REACTION C 56.5 g. of the above amine from reaction B, 49.5 g. of potassium hydrogen ll-suifoundecanoate, 151 ml. of dry pyridine and 570 ml. of dry benzene were charged into a l-liter, S-neck flask equipped wtih stirrer, Dean-Stark moisture trap, reflux condenser, calcium chloride tube and a dropping funnel. The mixture was refluxed until all traces of water were removed (requires about 2 hours). The mixture was then cooled in an ice water bath and a solution of 7 ml. of phosphor trichloride in 50 ml. of dry benzene was added dropwise under rapid stirring. The addition required about 1 hour. The mixture was refluxed on a steam bath for 2 hours. Then, a solution of 12 g. of sodium hydroxide and 30 g. of sodium acetate in 50 ml. of water was added. The reaction product was stored for 15 hours in a refrigerator, filtered on a Buchner funnel and recrystallized from acetic acid.

The compound produced was:

(Compound 7) a Our invention is not limited to the detailed description contained herein, but includes all modifications that fall within the scope of the appended claims.

We claim:

1. The method of incorporating in a photographic silver halide hydrophilic emulsion a salt of a color coupler of the following formula:

C O-NH-R (CH2)n-1 SOaM wherein M is selected from the class consisting of ammonium and an alkali metal, R represents a coupler molecule of the type capable of coupling with the oxidation prod ucts of a primary aromatic amino developing agent, said coupler molecule being selected from the class consisting f l-hydroxy-Z-naphthoic radicals, OL-bCl'lZOyl acid anilide radicals, and 3-(l-phenyl-S-pyrazolone) radicals and n represents a positive integer of at least 9 which comprises dissolving said coupler salt in dimethylformamide, mixing the resulting solution of said coupler with a solution of the hydrophilic colloid used in the preparation of the hydrophilic emulsion, setting the resulting dispersion, shredding the set dispersion, washing the shredded set dispersion to remove the dimethylformamide therefrom and mixing the washed dispersion with the said photographic silver halide hydrophilic, emulsion in order to form a mixture of said coupler salt in said gelatino silver halide emulsion.

2. The method as recited in claim 1 wherein the photographic silver halide hydrophilic emulsion is a photographic gelatino silver halide emulsion.

References Cited in the file of this patent UNITED STATES PATENTS 2,498,466 Thompson Feb. 21, 1950 2,533,514 Sawdey et al Dec. 12, 1950 2,829,975 Popeck et al Apr. 8, 1958 2,902,366 Sprung et a1 Sept. 1, 1958

Claims (1)

1. THE METHOD OF INCORPORATING IN A PHOTOGRAPHIC SILVER HALIDE HYDROPHILIC EMULSION A SALT OF A COLOR COUPLER OF THE FOLLOWING FORMULA: