GB1603223A - 5-pyrazolone magenta couplers for photographic use photographic elements containing them and processing for the manufacture thereof - Google Patents

Abstract

A two-equivalent magenta coupler with a 5-pyrazolone ring contains the following substituents a) a phenyl group substituted by at least one halogen atom in the 1-position, b) an anilino or amide group in the 3-position and c) a 1,2,4-triazole group in the 4-position, of the general formula <IMAGE> in which R is a hydrogen atom or a C1-3-alkyl radical and R1 is a chlorine atom or a C1-3-alkyl radical, R and R<1> not simultaneously being alkyl radicals. A process for preparing the magenta coupler is described. The abovementioned magenta coupler can be used for producing colour-photographic recording material which contains colour couplers in at least one of the silver halide emulsion layers.

Description

(54) 5-PYRAZOLONE MAGENTA COUPLERS FOR PHOTOGRAPHIC USE, PHOTOGRAPHIC ELEMENTS CONTAINING THEM AND PROCESSING FOR THE MANUFACTURE THEREOF (71) We, MINNESOTA MINING AND MANUFACTURING COMPANY, a Corporation organized and existing under the laws of the State of Delaware, United States of America, of 3M Center, Saint Paul, Minnesota 55101, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement:- The present invention relates to color couplers for photographic use, to photographic elements containing them and to the processing for the manufacture thereof. In particular, the present invention refers to 5 - pyrazolone magenta couplers.

It is known that in photography couplers are used which, in the presence of exposed silver halide, are capable of reacting with p - phenylene diamine developers to form a dye which is image-wise distributed in the developed photographic element.

Such couplers must be stable in every storage condition to which they are submitted in normal use and must form stable photographic dyes with the least possible silver consumption.

Couplers normally require four equivalents of reduced silver halide to form each dye molecule, but in the photographic art, where it is possible, the use of special couplers requiring only two reduced silver halide equivalents for each dye molecule which is formed is more desirable.

Such couplers can be used in a developing bath (bath couplers)-where they must not bear ballasting groups which hinder their diffusion-or can be used in light-sensitive elements, associated with silver halide emulsions contained therein.

In this case they should bear terminal aliphatic chains which make the coupler molecule a non-diffusing one.

Such non-diffusing couplers can be introduced into the photographic layer containing them (generally the silver halide emulsion layer or a layer adjacent thereto) either in an alkaline water solution (in this case at least an acid solubilizing group of the SO3H or COOH type must be introduced into the coupler molecule itself), or dissolved in a high-boiling organic solvent dispersed in the coating composition of the layer itself.

Briefly, this second method, which at present is the preferred one, is called a "dispersion method" and consists first of dissolving the coupler in a substantially water-immiscible organic solvent and then of dispersing the so-obtained solution as extremely tiny droplets into a hydrophilic colloidal binder. Gelatin is the preferred hydrophilic colloidal binder, but other known polymeric colloidal binders can also be used. (A description of the dispersion method can be found in U.S. Patents 2,322,027; 2,801,170; 2,801,171 nd 2,991,177).

The dye formation reaction must have certain desirable characteristics which involve for instance fineness of the image grain and modulated contrast (as for instance described in the U.S. Patents 2,689,793; 2,742,832: 2,998,314 and 3,227,554).

The magenta couplers now widely used in color photography are those derived from 5 - pyrazolone having a phenyl group in the 1-position thereof. In particular.

useful couplers may be those having in the 1-position of the 5 - pyrazolone a phenyl group substituted in at least one of the 2, 4 and 6 positions with a halogen atom, such as for instance those described in the U.S. Patents 2,600,788 and 3,062,653.

Particularly useful couplers include a phenylamino (anilino) group attached in the 3-position of the 5 - pyrazolone, as for instance described in U.S. Patents 2,311,082; 2,983,611; 3,127,269 and 3,152,896.

In the present invention two-equivalent magenta 5 - pyrazolone couplers having in the l-position a phenyl group substituted with at least a halogen atom in one of the 2, 4 and 6 positions and an anilino group in the 3-position are shown.

Although wide literature has been written on 5 - pyrazolones, it is not believed that two-equivalent magenta couplers are at present used in the photographic materials sold on the market. This is because it is difficult both to find couplers that perform in the proper manner and also to prepare the compounds themselves.

The couplers of the 3 - anilino - 5 - pyrazolone type, for instance, have had a limit in their experimentation because of the fact that no pyrazolone formation upon reaction of a phenylhydrazine with compounds of the ethylacetylmalonate mono - thio - anilide type was observed, as described for instance in J. Am. Chem.

Soc., 44, 1551-57 (1922).

Such difficulties could apparently be overcome by reacting a compound of the ethyl a - aryl - oxy - fi - methylthio - fi - anilino - acrylate with an aromatic hydrazine, a method which has been used for the couplers described in U.S. Patent 3,419,391. Such methods are not useful for the general information of twoequivalent 5- pyrazolone magenta couplers, and the couplers specifically described in the above mentioned patent have not found any useful practical employment.

Only recently have there been any patent publications concerning 2equivalent 5 - pyrazolone couplers of commercial interest. West German Patent Publications DT 2,536,191 and DT 2,703,589, and Japanese Patent Publication 2,093,768 are amongst the most significant publications on this subject.

DT 2,703,589 discloses 1 - (halogenated phenyl) - 5 - oxo - 2 - pyrazolone 2equivalent magenta couplers having a 5- or 6-membered heterocyclic group attached to the 4-position of the pyrazolone neucleus. Amongst these substituent groups are specifically shown imidazolyl (and certain derivatives), 1,2,3 - triazole (and certain derivatives), and 1,2,4 - triazoles (and certain derivatives). The 1,2,4 triazole compounds specifically disclosed have only amine, carboxylic and alkyl substituents on the 3- and 5-positions. These compounds are formed by direct reaction of the appropriate triazole with the 5 - pyrazolone.

Japanese Publication 2,093,768 discloses 5 - pyrazolones having 5- or 6membered heterocyclic substituents in the 4-position with greater than two nitrogen atoms. Amongst the heterocyclic substituents shown are 3,5 - dichloro 1,2,4 - triazole.

Another is that described in the German Patent Application DT-OS 2,536,191, where certain described 2-equivalent couplers are obtained by melting the 5 pyrazolone compound, having a halogen atom in the 4-position, with a nitrogenated heterocyclic compound, which substitutes said halogen atom.

The above method is believed to be inadequate for the industrial preparation of the coupler since many products resulted at the same time and the separation thereof is very difficult.

According to the present invention, desirable 2-equivalent 5 - pyrazolone magenta couplers and a method for the preparation thereof are shown. The method allows the formation of a unitary product on an industrial scale.

The present invention refers to 2-equivalent 5 - pyrazolone magenta couplers including a halogen-substituted phenyl group in the 1-position, an anilino, benzamide or aromatically substituted amide group in the 3-position and a 1,2,4 triazole group, substituted with a chlorine atom or alkyl group in the 3-position and with a lower alkyl group or hydrogen atom in the 5-position, in the 4-position of the 5 - pyrazolone nucleus itself.

The present invention includes the 5 - pyrazolone magenta couplers described above, having one or more terminal antidiffusing aliphatic chains attached to the phenyl in the 1-position and/or to the aniline, benzamide or amide phenyl in the 3position.

More particularly, the present invention includes 5 - pyrazolone magenta couplers, as described above, wherein said terminal aliphatic chains are attached to the aniline, benzamide or amide phenyl in the 3-position directly (through a simple covalent bond) or indirectly through a "complex bond" (as explained hereinafter).

The present invention relates to photographic elements including a supporting base and at least a silver halide layer associated with a non-diffusing coupler, as described above.

The present invention in particular refers to photographic elements, as described above, containing the coupler as per the present invention dissolved in a high-boiling organic solvent and dispersed in the layer.

In another aspect, the present invention relates to a process for manufacturing the 2-equivalent 5 - pyrazolone couplers of the present invention including: a) the reaction of an alkyl - a - halogen - acetacetate with the appropriate 1,2,4 - triazole compound in the presence of a nitrogenated organic base and an organic solvent; b) the reaction of the alkyl - a - triazolyl - acetacetate, obtained upon said reaction (a), with a phenylisothiocyanate; c) the reaction of the a - triazolyl - thio - malonanilide compound, obtained in (b), with a halogen-substituted phenylhydrazine in the presence of a carboxylic acid alkylester as a solvent; and finally the cyclization of the so-obtained hydrazone.

Phenyl halogen-substituted in the 1-position of the 5 - pyrazolone herein means a phenyl group bearing at least one halogen-substituent, preferably chlorine or bromine, in one of the 2, 4 and 6 positions. Further to said halogen-atom(s), the phenyl group may have one or more substituents, preferably in one or two of the 2, 4 and 6 positions, chosen among the substituents known in the art, such as e.g. CF3, -CN, carboester (i.e., alkylester of a carboxylic acid), alkyl and alkoxy in which the carbon atoms are present in a number ranging from 1 to 18, preferably from 1 to 8, more preferably methyl or methoxy.

Attached in the 5-position of 3 - chloro - 1,2,4 - triazole, an H or alkyl group having from 1 to 3 carbon atoms, preferably 1 or 2 carbon atoms is herein intended.

The terminal aliphatic chains, preferably terminal alkyl groups, attached to the phenyl in the l-position or preferably to the phenyl in the 3-position of the 5 pyrazolone, have the function of making the molecule non-diffusing and include at least 8 carbon atoms, up to 30 carbon atoms, and preferably from 10 to 20 carbon atoms.

A complex bond between the anti-diffusing aliphatic chains and the phenyl of the group in the 3-position of the 5 - pyrazolone, means a divalent group including one or more of the following divalent radicals: phenylene, oxygen, sulfur, amino, alkylene, carbonyl, sulfonyl or combinations thereof, such as for instance carbonylamino, alkylenecarbonylamino, oxyalkylenecarbonylamino and phenyloxyalkylenecarbonylamino, or succinimido and phthalimido (as for instance described in GB Patent 997,550).

The reaction (a), which is a part of the manufacturing process according to the present invention, is critical because it neither occurs nor gives acceptable results with 3,5 - dimethyl - 1,2,4 - triazole under various reaction conditions, while it does occur with good yields by employing an unsubstituted 1,2,4 - triazole or a 1,2,4 - triazole substituted in the 3-position with a chlorine atom and in the 5position with hydrogen or lower alkyl.

The conditions of said reaction were the normal conditions of an acid-base condensation reaction, preferably addition of a nitrogenated organic base of the trialkylamine type (e.g. triethylamine, triethanolamine or diethylaniline) and use of an organic solvent of the acetone or acetonitrile type.

The reaction (b) occurs in the presence of a nitrogenated organic base (of the trialkylamine type) or of an inorganic base (of the sodium methylate, sodium carbonate, etc. type), in the presence of an organic solvent (e.g.

dimethylformamide, acetonitrile, alcohol, acetone, ether).

The reaction (c), in which the hydrazone is formed, is critical in the choice of the solvent. While it did not occur or occurred with very low yields in the presence of acetic acid and ethyl alcohol and occurred with insufficient yields with dioxane and acetonitrile, it gave good yields if carried out in the presence of an alkyl ester of a carboxylic acid, preferably an alkyl ester having a boiling point ranging from 30 to 1500C and more preferably from 50 to 1000C. (Carboxylic acid alkylester solvents, tested as per what said above, are for instance: methyl formate, ethyl formate, methyl acetate, ethyl acetate, isopropyl acetate, t-butyl acetate, n-propyl acetate, n-butyl acetate, isoamyl acetate and ethyl propionate).

The reaction (c) leads to the formation of a hydrozone, the cyclization (d) of which gives origin to the desired 5 - pyrazolone nucleus. Such cyclization (d) occurs, without the necessity of isolating the reaction product (c), as a normal continuation of the same reaction (c), preferably upon addition of base (e.g. sodium methylate and sodium carbonate) or of an acid (e.g. acetic acid).

In the particular case where the phenylisothiocyanate of reaction (b) has a nitro-group (-NO2), the final 5 - pyrazolone compound will have in the 3-position an anilino group having attached thereto a nitro-group which can be easily reduced to an amino group, for the possible introduction therein of terminal aliphatic chains, by means of reactions known to those skilled in the art, e.g. by means of the condensation of the so-obtained amine with acid chlorides or anhydrides.

It is at least in part because of the difficulties met in the preparation of 5 pyrazolone couplers and the properties critical to their photographic behavior that it is believed that the present invention describes unique couplers for photographic use.

It has been found in the practice of the present invention that the selection of particular substituents on a 1,2,4 - triazole group attached to a 5 - pyrazolone magenta coupler is critical to the usefulness of those couplers.

According to the present invention it has been found that 2-equivalent magenta couplers of the formula

wherein R2 is Cl or Br (preferably Cl), R3 and R4 are independently H, Cl, Br, or C1 to C3 alkyl or alkoxy (preferably Cl, Br, -OCH3 or -CH3; most preferably Cl or -CH3), R5 is alkylene of 1 to 4 carbon atoms or alkylene oxide of 1 to 4 carbon atoms with the 0 atom of the latter bonded to Ar, m is 0 or 1, n is 0 or 1 and never exceeds m, Ar is a mononuclear phenyl group which may or may not be substituted, R is H or alkyl of 1 to 3 carbon atoms, and R' is Cl or alkyl of 1 to 3 carbon atoms, except that R and R1 may not be the same (i.e., alkyl), provided excellent properties in color photographic emulsions, particular with regard to low fog, reactivity, and contrast. Preferred Ar groups are selected from

wherein R6 may be H, alkyl (up to 25 carbon atoms), or alkoxy (up to 25 carbon atoms).

and R7 and R8 may be H, alkyl (up to 25 carbon atoms), alkoxy (up to 25 carbon atoms), or phenoxyalkyleneamido (preferably butyramido), further wherein only one of R7 and R6 may be other than H at the same time and only one of R6 and R7 may be other than H at the same time.

Most preferably, when R7 or R8 is phenoxy alkyleneamido, the phenoxy group thereof has a 3-alkyl or 3-alkoxy substituent of 12 to 25 carbon atoms, or the 2- and 4-positions thereof are both substituted with alkyl or alkoxy groups having at least 3 carbon atoms each and totaling at least 9 carbon atoms. When m is 0, the phenoxyalkyleneamido group is preferably attached in the para-position, and when m is 1, the phenoxyalkyleneamido group is preferably attached in the metaposition.

The attempts made by the Applicant of obtaining 2-equivalent 5 - pyrazolone couplers, useful in photography, having in the 4-position thereof a non-substituted or a differently substituted 1,2,4 - triazole (e.g., only a chlorine atom in the 5position or a methyl group both in the 3 and 5 positlons) have been unsuccessful due either to difficulties of preparation (e.g., 3,5 - dimethyl - 1,2,4 - triazole) or to bad properties of the obtained coupler (poor solubility of the unsubstituted 1,2,4 triazole and excessive reactivity with fog in the case of 5 - chloro - 1,2,4 - triazole).

Some couplers made according to the present invention are as follows:

The couplers of the present invention may be used in association with many types of silver halide emulsions suitable for color photography. They can be used for instance with silver bromide, silver chloride or silver iodide emulsions or with those emulsions containing a halide mixture, such as silver bromo-iodide or silver chloro-bromide emulsions. The couplers can also be used with those emulsions which are described in U.S. 2,592,243 and 2,698,794. These couplers can be used with emulsions capable of forming an image on the surface or in the interior of the silver halide grains, such as those described in U.S. 2,592,250.

When the couplers of the present invention are included in photographic elements prior to their exposure and development, they can be directly introduced into the emulsions before their coating onto photographic base or into a layer adjacent thereto.

As it is known to the man skilled in the art, the above mentioned emulsions can be chemically sensitized either by addition of sulfur compounds, as described for instance in U.S. 1,574,944; 1,623,469; 2,410,689; and by addition of noble metal salts, such as ruthenium, rhodium, iridium, palladium and platinum. Such emulsions can be chemically sensitized by addition of Au salts, as described in U.S.

2,399,083. They can be stabilized with Au salts as described in U.S. 2,597,856 and 2,587,915.

The above emulsions can be optically sensitized with carbocyanine dyes such as those described for example in U.S. 2,503,776.

The emulsions can contain organic stabilizers and antifoggants of the cyclic amide type; iminoazoles such as mercapto - benzimidazole; triazoles such as those described in U.S. 2,444,608; azaindenes such as those described in U.S. 2,444,605; 2,444,606, 2,444,609; 2,450,397; 2,713,541; 2,716,062; 2,735,769; 2,743,181; 2,756,147; 2,772,164 and in E. J. Birr, Z. Wiss. Phot. 472 (1952); tetrazoles such as 1 - phenyl - 5 - mercapto - tetrazole; thiazoles and benzothiazoles such as 1 methyl - benzothiazole and benzothiazole quaternary salts, as described in U.S.

2,131,038; mercapto-benzothiazoles such as I - methyl - mercapto benzothiazole; oxazoles, thiosemicarbazydes; pyrimidines; iodonium derivatives; benzensulphynic acids; inorganic stabilizers of the zinc and cadmium salt type such as those described in U.S. 2,839,405.

The emulsions can further contain any suitable plasticizer known to the man skilled in the art such as glycerin.

The emulsion may be hardened with any suitable hardener for gelatin, known to the man skilled in the art such as aldehyde of the formaldehyde, glyoxale, succinic, glutaric and resorcyclic aldehyde type; and halogen substituted aliphatic acids such as mucochloric and mucobromic acids as described in U.S. 2,080,019; or mixture thereof as described in U.S. 2,591,542.

The emulsions may have been supplied with a coating aid, known to the man skilled in the art such as saponin. Any suitable base type, known to the man skilled in the art, can be used, such as cellulose triacetate, polyester, paper, polytenated paper. In the preparation of the silver halide dispersions, employed for preparing silver halide emulsions, there may be employed as the dispersing agent for the silver halide in its preparation, gelatin or another water-permeable means of the colloidal albumin type, a cellulose derivative, or a synthetic resin of the polyvinyl type. Such material types are described in U.S. 2,286,215; 2,328,808; 2,322,085; 2,527,872; 2,541,474; 2,563,7912,768,154; 2,808,331; 2,852,382. If desired, a mixture of two or more of these colloids may be employed for dispersing the silver halide in its preparation.

The couplers of the present invention, used alone or in combination with 4 equivalent couplers, proved to be particularly useful in a color photographic material of the negative type using the masking technique (including masked couplers in addition to main couplers as for instance described in U.S. 2,428,054; 2,808,329; 2,860,975 and 2,852,370) and the double layer technique (as for example described in UK 818,687).

In addition to the main couplers and masked couplers, other additional couplers can be used, such as for instance the couplers described in U.S. 2,689.793; 2,742,832; 2,998,314 and 3,227,554.

The developing baths to be used in conjunction with the couplers of the invention are well-known to the man skilled in the art. They contain a developer of the p - phenylene diamine type, a development restrainer of the potassium bromide type, an antioxidant, such as sodium sulfite and an alkaline agent of the alkali hydrate or carbonate type. They may further contain both an antifoggant of the benzimidazole type and derivatives, of the benzothiazole type and derivatives, of the triazole and tetrazole type and derivatives, such as mercapto-derivatives; and an anti-calcium substance of the alkaline phosphate and alkylene diaminoacetic acid type, such as for instance ethylenediaminetetraacetic acid. Known compounds of the p - phenylene diamine type are those described for instance in U.S.

2,193,015; 2,656,273; 2,875,049 and in C. E. Kenneth Mees and T. H. James, The Theory of the Photographic Process, third edition, table 13.4, pages 29W295.

Suitable developers, which can be employed to develop photographic elements, containing the couplers of the present invention, are the sulfites, the hydrochlorides and the sulfates of: a) N,N - diethyl - p - phenylene diamine; b) N - ethyl, N - - methansulfonamido - ethyl - 3 - methyl - 4aminoaniline; c) N - ethyl, N - hydroxyethyl - 2 - methyl - p - phenylene diamine; d) N - ethyl, N - hydroxyethyl - p - phenylene diamine; e) N,N - diethyl - 2 - methyl - p - phenylene diamine.

The following couplers, known in the art, have been tested against couplers of the present invention for comparison purposes:

EXAMPLES 1--9 Preparation of Coupler 1 1 -(2,4,6-trichlorophenyl)-3-[4-(a-2,4-ditert-amylphenoxy)butyramido]- anilino-4-(3-chloro-5-methyl- 1 ,2,4-triazolyl)-5-pyrazolone a) Preparation of Ethyl a - (3 - chloro - 5 - methyl - 1,2,4 - triazolylacetoacetate (Intermediate A) 39.5 g of ethyl - a - chloro - acetacetate, 600 ml of dry acetone, 28.2 g of 3 chloro - 5 - methyl - 1,2,4 - triazole and 84 ml of triethylamine were refluxed for 30 hours. The mixture was then cooled and the triethylamine hydrochloride filtered off. The solvent was evaporated under vacuum and the brown oil residue was extracted with ether. The ethereal solution was acidified to pH 4--5 with 1% HCI under shaking, separated from the aqueous layer, dried with anhydrous sodium sulfate and evaporated. The residue was fractionated under vacuum. Boiling point=135--1360C/1.5 mm Hg. 41.5 g were obtained.

b) Preparation of Ethyl - a - (3 - chloro - 5 - methyl - 1,2,4 - triazolylmalonate Monothio - 4 - nitro - anilide (Intermediate B) 53.4 g of intermediate A, 400 ml of dry dimethylformamide, 39.2 g of pnitro - phenylisothiocyanate and 30.2 g of triethylamine were mixed and heated at 60"C for 16 hours. The resulting deep red-orange solution was then poured into 1200 ml of iced 2% aqueous solution of sodium carbonate under stirring. After about one hour the turbid solution was filtered and the filtrate was acidified with dilute HCI. After standing for few hours the clear solution was poured off and the deep orange viscous oil was crystallized from methanol and water thus obtaining a yellow solid melting at 136-1380C.

Analysis: Found Calculated for C14H14C1N5O4S C% 43.45 43.81 H% 3.70 3.68 N% 18.05 18.24 ClV0 9.12 9.23 SC/o 8.27 8.35 c) Preparation of 1 - (2,4,6 - trichlorophenyl) - 3 - (4 - nitro - anilino) - 4 - (3 chloro - 5 - methyl - 1,2,4 - triazolyl) - 5 - pyrazolone (Coupler 5 Compound C) 23 g of intermediate B, 19 g of 2,4,6 - trichlorphenylhydrazine and 70 ml of ethyl-acetate were mixed and heated in a steam bath for 18 hours. The mixture was cooled at 50"C, 300 ml of methanol and6.5 g of sodium methoxide were added and the resulting red-brown solution was refluxed for 10 minutes. The solvent was evaporated under reduced pressure and the residue was shaken with 300 ml of water and 100 ml of ether. The ethereal solution was eliminated, the aqueous solution was extracted again with ether and then acidified with HCI. The yellow solid product which precipitated was collected on a Buchner funnel, washed with cold water, dried and recrystallized from acetonitrile. 28.4 g of a yellow crystalline solid were obtained. M.p.-1830C with decomp.

Analysis: Found Calculated for C18H14Cl4N7O3 C% 42.03 41.97 Hv 2.18 2.15 N% 19.08 19.03 CW0 27.44 27.53 d) Preparation of 1 - (2,4,6 - trichlorophenyl) - 3 - (4 - amino - anilino) - 4 - (3 chloro - 5 - methyl - 1,2,4 - triazolyl) - 5 - pyrazolone (Compound D) 23.4 g of Coupler 5-Compound C were mixed with 180 ml of ethanol, 70 ml of acetic acid and 20 ml of water. The mixture was heated to reflux, 25 g of powdered iron were added cautiously, in little portions, then refluxed for one additional hour.

After filtration on a Buchner funnel that hot solution was diluted with 300 ml of water, extracted with ethyl acetate and the solvent was evaporated under reduced pressure. The resulting brown viscous oil was recrystallized from a mixture of CH3CN and EtOH, thus obtaining 18.2 g of a white-grey solid which decomposed at 190"C.

e) Preparation of the Coupler 9.7 g of Compound D were suspended in 300 ml of acetonitrile, then 6.8 g of a (2,4 - ditert - amylphenoxy)butyrylchloride were added at once. The suspension was refluxed for 3 hours and the resulting solution was kept at room temperature for 24 hours. The white solid which precipitated was collected on a Buchner funnel, washed with pure acetonitrile and dried thus obtaining 11.4 g The listed couplers 2-9 were prepared in a similar way but using the appropriate intermediates.

The analytical data of the listed couplers are reported in Table 1.

TABLE 1 Coupler M.p. Found Calculated No. C C% H% N% Cl% C% H% N% Cl?/0 220222 57.70 5.48 12.48 18.08 57.95 5.50 12.44 18.00 2 159-163 56.84 5.48 11.85 17.38 57.29 5.55 11.99 17.34 3 108-1 12 60.34 6.15 11.33 16.49 60.21 6.23 11.43 16.54 4 157-159 57.86 5.52 12.38 17.95 57.95 5.50 12.45 18.01 5 183 dec 42.03 2.18 19.08 27.44 41.97 2.15 19.03 27.53 6 223-225 38.73 1.79 14.42 20.68 38.79 1.78 14.39 20.82 7 22" 35.57 1.40 11.21 16.08 35.44 1.37 11.12 16.09 8 152-155 63.90 6.63 ~ 12-.9y- 9.41 64.33 6.61 13.13 9.50 9 160165 64.06 6.62 13.01 9.55 64.33 6.61 13.13 9.50 EXAMPLE 10 To an orthochromatically sensitized silver bromo - iodide negative photographic emulsion was added the 2-equivalent magenta coupler No. 3 in a quantity of 83.13 mM/Ag mole. The finally obtained emulsion was then coated on a cellulose triacetate base at a silver covering weight of 1-.1 g/m2.

Similarly, the same emulsion was added with the 4-equivalent magenta coupler A in a quantity of 41.56 mM/Ag mole. The finally obtained emulsion was then coated on a supporting base, as said above, at a silver covering weight of 2.2 g/m2.

The obtained sensitometric samples underwent then an accelerated incubation for 10 days at 380C and 75% R.H. At the end of such incubation, the samples were exposed at a sensitometer normalized with a 0.30 logit gradient wedge, at a color temperature of 5500"K, together with the corresponding samples incubated at room conditions. All samples were then developed, at the same time, in a standard developer for color negative films and finally read with an automatic densitometer, thus ob emulsion was then coated on a cellulose triacetate base at a silver covering weight of 2,2 g/m2.

A high-sensitivity silver bromo-iodide negative photographic emulsion, sensitized orthochromatically, was added with the 4-equivalent magenta coupler A in a quantity of 1.67 mM/Ag mole and with the magenta masked coupler B in a quantity of 1.67 mM/Ag mole. The emulsion was finally coated on the mediumspeed layer at a silver covering weight of 1.4 g/m2.

A gelatin protective layer was then coated on the so-obtained film.

A sample of the two films was then exposed on a sensitometer normalized with a 0.30 logit gradient wedge, at a color temperature of 5500"K, and developed with a standard developer for color negative films. The so-obtained results are evidenced by the enclosed diagram wherein the dotted line corresponds to film 1 and the united line corresponds to film 2.

The reaction of the - triazolyl - thio - malonanilide with the phenylhydrazine is also an inventive aspect of this patent application. This process, comprises the reaction of an a - triazolyl - thio - malonanilide with a halogen substituted (on the phenyl ring) phenylhydrazine. Other substituents (e.g., alkyl, alkoxy, and fused phenyl to make a naphthyl group) may be present on the phenyl ring in addition to the halogen. Preferred are ortho-halogen substituents (e.g., 2-, 2,4-, 2,4,6-substituted halogen). Amongst the additional substituents used with halogen substituents, lower alkyl (C1-C3) and most particularly methyl are preferred, particularly as o- and p-substituents.

The process of preparing the benzamide substituted 5 - pyrazolone couplers of the present invention is as follows: 1) reaction of an a - halogen - a - carboalkyloxyacetamide with a 1,2+4 triazole in the presence of a base, 2) the reaction of the resulting a - triazolyl - a - carboalkyloxyacetamide with phosphorus pentasulfide, 3) the reaction of the resulting a - triazolyl - a - carboalkyloxythioacetamide with a substituted hydrazine, and 4) the cyclization of the resulting hydrazone with sodium alkylate.

The process is exemplified below.

EXAMPLE 12 Preparation of Coupler No. 10 1 -(2,4,6-trichloro-phenyl)-3-[3-a-(2,4-ditert-amylphenoxy)acetamido- benzamido]-4-(3-chloro-l ,2,4-triazolyl)-5-pyrazolone a) Preparation of a - bromo - a - carbethoxy - acetamide (Intermediate A) To a solution of 150 g (1.144 M) of a - carbethoxyacetamide in 1800 ml of dichloro - methane were added dropwise under stirring 182.7 g (1.144 M) of bromine dissolved in 200 ml of dichloro - methane at a temperature of 20 to 30"C.

The mixture was kept at room temperature under stirring for an additional hour and then 500 ml of water were added thereto under vigourous stirring. The organic layer was separated, dried with anhydrous CaClz and then evaporated under vacuum. The residue was dissolved in 200 ml of ethyl acetate and the resulting solution was poured under stirring in 1000 ml of heptane. 175 g of a grey solid were obtained. M.p.: 56-580C.

b) Preparation of a - (3 - chloro - 1,2,4 - triazolyl) - a - carbethoxyacetamide (Intermediate B) To a cold solution of 80 g of intermediate A and 44 g of 3(5) - chloro - 1,2,4 triazole in 750 ml of acetone, 33.5 g of powdered NaOH were added. The mixture was stirred for 2 hours at room temperature, neutralized with HC1 and filtered. The filtrate was evaporated under vacuum and the residue was crystallized from water, thus obtaining 54 g of a white product melting at 108--110"C.

Analysis: Calculated Found C% 36.14 36.24 H% 3.90 3.84 N% 24.09 24.13 Cl% 15.24 15.21 c) Preparation of a - (3 - chloro - 1,2,4 - triazolyl)- a - carbethoxythio acetamide (Intermediate C) To a solution of 46 g (0.2 M) of intermediate B in 300 ml of anhydrous dioxane, 11.1 g (0.05 M) of P2S5 were added. The mixture was refluxed for 2 hours cooled and filtered. The filtrate was evaporated under vacuum and the oily residue was used for the next reaction without further purifications.

d) Preparation of 1 - (2,4,6 - trichlorophenyl) - 3 - amino - 4 - (3 - chloro 1,2,4 - triazolyl) - 5 - pyrazolone (Intermediate D) The intermediate B was mixed with 53 g (0.25 M) of 2,4,6 - trichlorophenyl hydrazine and 150 ml of ethylacetate. The mixture was refluxed 18 hours and the solvent was evaporated under vacuum. To the resulting residue a solution of 21.1 g (0.4 M) of sodium methoxide in 400 ml of pure methanol was added. The solution was refluxed for 15 minutes and poured under stirring into 2000 ml of cold water.

The pH of the solution was then adjusted at --8 with diluted HCI. The solid was separated by suction and washed with water; the solution was acidified to litmus with diluted HCI. The solid separated was filtered, washed with cold water, dried and purified by digestion with boiling acetonitrile. 42.5 g were obtained. M.p.: 235"C.

e) Preparation of 1 - (2,4,6 - trichlorophenyl) - 3 - (3 - nitrobenzamido) - 4 - (3 chloro - 1,2,4 - triazolyl) - 5 - pyrazolone (Compound E) 37.1 g (0.098 M) of intermediate D, 500 ml of acetonitrile and 27.2 g (0.147 M) of m - nitrobenzoyl - chloride were mixed and refluxed for one hour and a half.

The solvent was then evaporated under vacuum and the residue stirred with 300 ml of 3% cold solution of NaOH. The resulting turbid solution was filtered and acidified with concentrated HCI. The solid was filtered, washed with water, dried and purified by digestion with boiling acetonitrile, thus obtaining of a pale yellowbrown solid melting at 2450 C/dec.

f) Preparation of 1 - (2,4,6 - trichlorophenyl) - 3 - (3 - aminobenzamido) - 4 (3 - chloro - 1,2,4 - triazolyl) - 5 - pyrazolone (Compound F) 26.4 g of compound E were dissolved in 250 ml of methyl Cellosolve and reduced at 500C with H2 at 20 atmosphere and Ni Raney. After cooling the Ni was filtered off and the solvent evaporated under vacuum. The solid residue was extracted with boiling ethanol and filtered thus obtaining 18 g of a white solid melting at 252"C. (The word "Cellosolve" is a Registered Trade Mark.) Preparation of the Coupler 5 g (0.01 M) of compound F, 50 ml of acetonitrile and 3 g of a - (2,4 - ditert amylphenoxy)acetylchloride were mixed together, refluxed for 2 hours and poured into cold water. The white precipitate was filtered, washed with cold water, dried and purified by crystallization from ethyl - acetate/acetonitrile. M.p.: 215"C.

Analysis: Found Calculated C% 55.42 55.90 H% 4.86 4.82 N% 12.5 12.67 Cl% 18.14 18.33 EXAMPLE 13 Preparation of Coupler No. 16 I -(2,4,6-trichlorophenyl)-3-[-(m-pentadecylphenoxy)butyramido]-4- (3-chloro-1,2,4-triazolyl)-5-pyrazolone 10 g of compound D from Example 12, 125 ml of acetonitrile and 16.1 g of a (m-pentadecylphenoxy)butyryl - chloride were mixed and refluxed for 3 hours.

The solvent was evaporated under vacuum and the residue was dissolved in 100 ml of ethyl-acetate. The solution was vigorously stirred for 10 minutes with a cold 10% solution of sodium hydroxide. After neutralization with HCI, the organic layer was separated, washed with water and the solvent was evaporated. The residue was crystallized from a 1:1 mixture of ethyl acetate/acetonitrile, thus obtaining 18.2 g of white product melting at 201--30C.

Analysis: Found Calculated C% 56.83 57.45 H% 6.02 6.16 N% 10.61 11.17 Cl% 18.25 18.84 With the general procedure described above, all of the benzamide couplers shown by the formula above have been prepared.

Comparison of these couplers with couplers having 3,5-dialkyl or 3,5-dichloro substitution on the 1,2,4 - triazole group showed remarkable comparative results.

The dialkyl and dichlorosubstituted couplers displayed either high fog levels, excessive reactivity, and/or undesirable contrast. The compounds of the present invention, and particularly the 3 - chloro - 1,2,4 - triazole compounds (with or without 5-position substitution) showed outstanding properties with regard to these sensitometric characteristics.

WHAT WE CLAIM IS: 1. A two-equivalent 5 - pyrazolone magenta coupler having as substituents: a) in the 1-position a phenyl group having at least one halgoen substituent in the 2, 4 or 6 position, b) in the 3-position an anilide, a benzamide group or an aromatically substituted amide, and c) in the 4-position a 1,2,4 - triazole of the formula: wherein

R is H or alkyl of I to 3 carbon atoms, and R' is Cl or alkyl of 1 to 3 carbon atoms such that R and R' are not both alkyl.

2. A magenta coupler as claimed in Claim 1, wherein R is a methyl group.

3. A magenta coupler as claimed in Claim I or 2, further including at least one terminal anti-diffusing aliphatic chain attached to at least one position selected from the anilide or benzamide phenyl.

4. A magenta coupler as claimed in Claim 1 represented by the formula

wherein R is H or alkyl of 1 to 3 carbon atoms, R3 and R4 are selected from Cl and alkyl or alkoxy of I to 3 carbon atoms, m is 0 or 1, n is 0 or 1 and never greater than m, R5 is alkylene of 1 to 4 carbon atoms or alkylene oxide of 1 to 4 carbon atoms with the 0 atom bonded to the phenyl ring of the terminal group, R6 is H, or alkyl of 1 to 25 carbon atoms, or alkoxy of 1 to 25 carbon atoms, R7 and R8 may be H, alkyl of 1 to 25 carbon atoms, alkoxy of 1 to 25 carbon atoms, or phenoxyalkyleneamido, R6, R7 and R8 chosen so that only one of R6 and R7 and only one of R7 and R8 may be other than H at the same time.

5. A coupler as claimed in Claim 4, wherein R3 and R4 are Cl, mis 1, n is 0, and R7 is a phenoxyalkyleneamido group.

6. A coupler as claimed in Claim 5, wherein R7 is a phenoxybutyramido group.

7. A coupler as claimed in Claim 6, wherein R7 has at least one terminal alkyl substituent on the phenoxy group thereof in the meta- or para-position.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (13)

**WARNING** start of CLMS field may overlap end of DESC **. With the general procedure described above, all of the benzamide couplers shown by the formula above have been prepared. Comparison of these couplers with couplers having 3,5-dialkyl or 3,5-dichloro substitution on the 1,2,4 - triazole group showed remarkable comparative results. The dialkyl and dichlorosubstituted couplers displayed either high fog levels, excessive reactivity, and/or undesirable contrast. The compounds of the present invention, and particularly the 3 - chloro - 1,2,4 - triazole compounds (with or without 5-position substitution) showed outstanding properties with regard to these sensitometric characteristics. WHAT WE CLAIM IS:

1. A two-equivalent 5 - pyrazolone magenta coupler having as substituents: a) in the 1-position a phenyl group having at least one halgoen substituent in the 2, 4 or 6 position, b) in the 3-position an anilide, a benzamide group or an aromatically substituted amide, and c) in the 4-position a 1,2,4 - triazole of the formula: wherein

R is H or alkyl of I to 3 carbon atoms, and R' is Cl or alkyl of 1 to 3 carbon atoms such that R and R' are not both alkyl.

2. A magenta coupler as claimed in Claim 1, wherein R is a methyl group.

3. A magenta coupler as claimed in Claim I or 2, further including at least one terminal anti-diffusing aliphatic chain attached to at least one position selected from the anilide or benzamide phenyl.

4. A magenta coupler as claimed in Claim 1 represented by the formula

wherein R is H or alkyl of 1 to 3 carbon atoms, R3 and R4 are selected from Cl and alkyl or alkoxy of I to 3 carbon atoms, m is 0 or 1, n is 0 or 1 and never greater than m, R5 is alkylene of 1 to 4 carbon atoms or alkylene oxide of 1 to 4 carbon atoms with the 0 atom bonded to the phenyl ring of the terminal group, R6 is H, or alkyl of 1 to 25 carbon atoms, or alkoxy of 1 to 25 carbon atoms, R7 and R8 may be H, alkyl of 1 to 25 carbon atoms, alkoxy of 1 to 25 carbon atoms, or phenoxyalkyleneamido, R6, R7 and R8 chosen so that only one of R6 and R7 and only one of R7 and R8 may be other than H at the same time.

5. A coupler as claimed in Claim 4, wherein R3 and R4 are Cl, mis 1, n is 0, and R7 is a phenoxyalkyleneamido group.

6. A coupler as claimed in Claim 5, wherein R7 is a phenoxybutyramido group.

7. A coupler as claimed in Claim 6, wherein R7 has at least one terminal alkyl substituent on the phenoxy group thereof in the meta- or para-position.

8. Photographic element including a supporting base and at least one silver

halide emulsion layer associated with the non-diffusing coupler of Claims 1. 2 or 3.

9. Photographic element including a supporting base and at least a silver halide emulsion layer associated with a coupler according to Claim 4, wherein that coupler is dispersed in the layer dissolved in a high-boiling organic solvent.

10. Process for manufacturing two-equivalent 5 - pyrazolone couplers described in Claims from 1 to 4 including: a) the reaction of an alkyl - a - halogen acetacetate with a 1,2,4 - triazole in the presence of a nitrogenated organic base and of an organic solvent; b) the reaction of the alkyl - a - triazolyl - acetate obtained upon reaction (a) with a phenyl - isothiocyanate; c) the reaction of the a - triazolyl - thio - malonanilide obtained upon reaction (b) with a halogen-substituted phenylhydrazine; and the cyclization of the obtained hydrozone, reaction (c) being carried out in the presence of a solvent comprising an alkyl ester of a carboxylic acid.

11. A two-equivalent 5 - pyrazolone magenta coupler as claimed in Claim I and substantially as herein described with reference to any one of the Examples.

12. A photographic element as claimed in Claim 8 substantially as herein described with reference to any one of the Examples.

13. A process for preparing a two-equivalent 5 - pyrazolone magenta coupler substantially as herein described with reference to any one of the Examples.