CH648938A5 - Two-equivalent magenta coupler, a process for its preparation and colour-photographic recording material - Google Patents

Description

The invention relates to two-equivalent color couplers, a process for their production and color photographic recording material with at least one light-sensitive silver halide emulsion layer in which these 65 color couplers are contained.

As is known, color images can be produced by chromogenic development. Here the photographic process of reducing the exposed halogen silver is included

3rd

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a dye coupling combined. Primary aromatic amines serve as developers, the oxidation products of which combine with the color couplers present to form the image dyes.

The color couplers must be stable under the storage conditions and should form stable photographic dyes with the lowest possible silver consumption.

Color couplers typically require four equivalents of reduced silver halide to form a dye molecule. However, it is preferred to use special color couplers in photography, which only require two reduced silver halide equivalents per dye molecule. Color couplers of this type can be used in a developer bath (bath coupler). In this case, they must not wear ballast groups that inhibit their diffusion. The color couplers can also be used in photographic material containing at least one silver halide emulsion layer. In this case, color couplers with terminal aliphatic chains are required to give the color couplers diffusion resistance.

The diffusion-resistant color couplers are generally incorporated into a silver halide emulsion layer or an adjacent layer of the photographic recording material either in the form of an aqueous alkaline solution or dissolved in a high-boiling organic solvent which is dispersed in the coating composition. When using an aqueous alkaline solution, the color coupler molecule must contain at least one sulfonic acid or car-boxyl group.

The second-mentioned process is also referred to as the "protected coupler" process, in which the color coupler is embedded in the finest droplets of water-insoluble organic solvents, which are then dispersed as the finest droplets in a hydrophilic colloidal binder, preferably gelatin. However, other known polymeric colloidal binders can also be used. The protected coupler method is described, for example, in U.S. Patents 2,322,027, 2,801,170, 2,801,171 and 2,991,177.

The dye formation should have certain desired properties, for example fineness of the image grain and modulated contrast. This is described, for example, in U.S. Patents 2,689,793.2,742,832.2,998,314 and 3,227,554.

The purple couplers common in color photography are derived from 5-pyrazolones which carry a phenyl group in the 1-position. Usable color couplers are, for example, those compounds which carry a phenyl group in the 1-position of the 5-pyrazolone ring which is substituted in at least one of the 2-, 4- and 6-positions by a halogen atom; see. for example, U.S. Patents 2,600,788 and 3,062,653.

Particularly useful magenta couplers contain an anino group in the 3-position of the 5-pyrazolone ring; see. for example, U.S. Patents 2,311,082.2,983,611.3,127,269 and 3,152,896.

There is extensive literature on 5-pyrazolone magenta couplers, but two-equivalent magenta couplers are not yet used. This is because it is difficult to find color couplers that have the desired properties and it is also difficult to make these compounds.

For example, color couplers of the 3-anilino-5-pyrazolone type were used only to a limited extent because no pyrazolone formation occurred when a phenylhydrazine was reacted with compounds of the ethyl acetylmalonate monothioanilide type; see. e.g. J. Am. Chem. Soc., Vol. 44 (1922), pp. 1551 to 1557.

Such difficulties can be overcome by reacting a compound of the α-aryloxy-β-methylthio-β-anilino-acrylic acid ethyl ester type with an aromatic hydrazine. This process was used to make the couplers described in U.S. Patent 3,419,391. However, these methods are of little use for the general manufacture of two-equivalent 5-pyrazo ion magenta couplers, and the color couplers specifically described in the U.S. Patent have not found practical use.

Only recently there have been publications on two-equivalent 5-pyrazolone color couplers that are of technical interest; see. DE-OSen 2 536 191 and 2 703 589 and JA-AS 20 937/68.

DE-OS 2 703 589 describes 1- (halophenyl) -5-oxo-2-pyrazolone two-equivalent magenta couplers with a 5- or 6-membered heterocyclic radical in the 4-position of the pyrazolone ring. Specifically described heterocyclic substituents are the imidazole group and certain derivatives, the 1,2,3-triazole group and certain derivatives and the 1,2,4-triazole group and certain derivatives. The 1,2,4-triazole compounds described in the 3- and 5-positions only carry amino or carboxyl groups or alkyl radicals. These compounds are prepared by directly reacting the corresponding triazole with the 5-pyrazolone.

JA-AS 20 937/68 describes 5-pyrazolones with 5- or 6-membered heterocyclic radicals in the 4-position with more than 2 nitrogen atoms. Among the heterocyclic residues is the 3,5-dichloro-l, 2-4-triazole group.

Finally, DE-OS 2 536 191 describes certain two-equivalent magenta couplers which have been prepared by condensing a 5-pyrazolone compound with a substitutable halogen atom in the 4-position with a nitrogen-containing heterocyclic compound. This process is unsatisfactory for the technical manufacture of the color couplers, since the implementation results in different products, the separation of which causes difficulties.

The invention has for its object to provide special two-equivalent magenta couplers with a 5-pyrazolone ring, which are characterized by particularly good properties in color photographic recording material. This object is achieved by the invention.

The invention relates to two-equivalent magenta couplers with a 5-pyrazolone ring and a) in the 1-position a phenyl group substituted by at least one halogen atom,

b) in the 3-position an anilino or amide group, preferably an amide group, and c) in the 4-position a 1,2,4-triazole group of the general formula in which R is a hydrogen atom or a Ci_3-alkyl radical and R1 is a chlorine atom or a CU3-alkyl radical, where R and R1 are not simultaneously alkyl radicals.

The following steps are carried out in the process according to the invention for producing the two-equivalent magenta couplers described:

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

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a) reaction of a cc-haloacetoacetic acid alkyl ester with a corresponding 1,2,4-triazole in the presence of a nitrogen-containing organic base and an organic solvent,

b) reaction of the alkyl a-triazolylacetoacetic acid obtained with a phenyl isothiocyanate,

c) reaction of the a-triazolylthiomalonanilide obtained with a corresponding halogen-substituted phenylhydrazine and cyclization of the hydrazone obtained.

The process according to the invention is characterized in that the reaction (c) is carried out in the presence of an alkyl carboxylic acid ester as solvent.

The magenta couplers according to the invention of the type described above have at least one aliphatic chain which gives terminal diffusion resistance and which is bonded to the phenyl group in the 1-position and / or to the benzene nucleus of the anilino or amide group, preferably the amide group.

In particular, the invention relates to magenta couplers of the type described above, in which the terminal aliphatic chains are bonded to the benzene nucleus of the anilide or amide group, in particular the benzamide group in the 3-position, by a covalent bond or indirectly by a complex bond of the type explained below.

The invention further relates to color photographic recording material, which is characterized in that it contains, in at least one of the light-sensitive silver halide emulsion layers, a magenta coupler according to the invention of the type described above.

A preferred color photographic recording material of the type described above contains the magenta coupler according to the invention dissolved in a high-boiling organic solvent and dispersed in the layer.

The phenyl group substituted by at least one halogen atom in the 1-position of the 5-pyrazolone ring means a phenyl group which has at least one halogen atom, preferably a chlorine or bromine atom in at least one of the

2-, 4- and 6-position. In addition to the halogen atom or atoms, the phenyl group can also carry at least one further substituent. The phenyl group preferably contains one or two substituents in the 2-, 4- and 6-position. Typical known substituents are, for example, the trifluoromethyl or cyano group, carboxylic acid alkyl ester, alkyl or alkoxy radicals having 1 to 18, preferably 1 to 8, carbon atoms. Particularly preferred residues are the methyl and methoxy groups. The 5-position of the 3-chloro-1,2,4-triazole group can have a hydrogen atom or an alkyl radical having 1 to 3, preferably 1 or 2, carbon atoms.

The terminal aliphatic chains, preferably terminal alkyl radicals on the phenyl group in the 1-position or preferably on the benzene nucleus of the anilino group in the

The 3-position of the 5-pyrazolone ring is said to impart diffusion resistance to the molecule. These radicals usually contain at least 8 and up to 30 carbon atoms, preferably 10 to 20 carbon atoms.

A complex bond between the aliphatic chains which impart diffusion resistance and the benzene nucleus of the anilino group or the amide group in the 3-position of the 5-pyrazolone ring usually means a divalent group, for example a phenylene group, an oxygen or sulfur atom, an amino or alkylene group. , Carbonyl or sulfonyl group or combinations thereof, for example a carbonylamino, alkylenecarbonylamino, oxyalkylene-carbonylamino or phenyloxyalkylenecarbonylamino group or a succinimido or phthalimido group, as described for example in GB-PS 997 550.

Step (a) of the process according to the invention is critical since it does not proceed with 3,5-dimethyl-1,2,4-triazole under the most varied reaction conditions and does not give acceptable results. However, in the preferred use of a corresponding unsubstituted 1,2,4-triazole or a 1,2,4-triazole which is substituted in the 3-position by a chlorine atom and in the 5-position by a hydrogen atom or a lower alkyl radical Reaction io in good yield.

The conditions of this reaction are usually the normal conditions of an acid-base condensation reaction, preferably the addition of a trialkylamine-type nitrogen-containing organic base, such as triethylamine, triethanolamine or diethylaniline. Acetone and acetonitrile are preferred as the organic solvent.

Step (b) is preferably carried out in the presence of a trialkylamine-type nitrogen-containing organic base or an inorganic base such as sodium methylate or sodium carbonate in the presence of an organic solvent such as dimethylformamide, acetonitrile, an alcohol, acetone or an ether. In step (c), in which the hydra-zone is formed, the type of solvent used is critical. In the presence of acetic acid or ethanol, the reaction either does not proceed or in very low yield. When using dioxane or acetonitrile, the yield is unsatisfactory. Good yields are obtained if the reaction according to the invention is carried out in the presence of an alkyl carboxylate, preferably an ester having a 30o boiling point of 30 to 150 ° C., in particular 50 to 100 ° C. Specific examples of carboxylic acid alkyl esters which can be used are methyl formate, ethyl formate, methyl acetate, ethyl acetate, isopropyl acetate, tert-butyl acetate, 35-ester, n-propyl acetate, n-butyl acetate and isocyanate propyl acetate and isocyanate propyl acetate.

Step (c) leads to the formation of a hydrazone and in this step the 5-pyrazolone ring is formed. The resulting product does not have to be isolated for cyclization. In general, an inorganic base, such as sodium methylate or sodium carbonate, or an acid, such as acetic acid, is added in step (c) after the reaction has ended.

In the special case of using a phenylisothiocyanate in step (b) with a nitro group, the 5-pyrazo-45 ion compound in the 3-position contains an anilino group substituted by a nitro group, which can easily be reduced to an amino group and then in itself in a known manner, for example by reaction with acid chlorides or anhydrides.

It has been found that the choice of certain substituents on a 1,2,4-triazole group which is on a purple coupler of the 5-pyrazolone type is of crucial importance for the usefulness of these couplers.

Preferred two-equivalent purple couplers according to the invention have the general formula I.

648 938

in which R2 is a chlorine or bromine atom, preferably a chlorine atom, R3 and R4 are hydrogen, chlorine or bromine atoms or Cj_3-alkyl or Ci_3-alkoxy radicals, preferably chlorine or bromine atoms, methoxy or methyl groups and in particular chlorine atoms or methyl groups. R5 is a Ci ^ alkylene radical or a C | ^ alkylene oxide radical, the oxygen atom being bonded to the Ar radical. m has the value 0 or 1 and n the value 0 or 1, but n is not greater than m. Ar is an optionally substituted phenyl group, R represents a hydrogen atom or a Ci_3-alkyl radical and R1 represents a chlorine atom or a Ci_3-alkyl radical. R and R1 are not intended to represent alkyl radicals at the same time. These magenta couplers have excellent properties in color photographic recording material, particularly with regard to low fog, responsiveness and contrast.

The group Ar preferably has the general formula in which R6 represents a hydrogen atom, a Ci_25-alkyl or Ci_25-alkoxy radical and R7 and R8 hydrogen atoms, Ci_25-alkyl or Ci_25-alkoxy radicals or phenoxyalkyleneami-

dog groups, preferably butyramido groups, and at the same time only one of the radicals R6 and R7 and only one of the radicals R7 and R8 has a meaning other than a hydrogen atom. The radical R7 or R8 5 preferably denotes a phenoxyalkyleneamido group. The phenoxy group preferably contains in the 3-position an alkyl or alkoxy radical with 12 to 25 carbon atoms, or the 2- and 4-positions are both substituted by alkyl or alkoxy radicals with at least three carbon atoms and a total of at least 9 10 carbon atoms . When m is 0, the phenoxyalkylene amido group is preferably in the p-position, when m is 1, preferably in the m-position.

Attempts to produce two-equivalent magenta 15 couplers of the 5-pyrazolone series which have an unsubstituted or differently substituted 1,2,4-triazole radical in the 4-position, for example only one chlorine atom in the 5-position or methyl groups in both the 3 - As well as 5-position, were unsuccessful either due to difficulties in the manufacture (for example in the case of 3,5-dimethyl-1,2,4-triazole) or to poor properties of the color couplers obtained (poor solubility of the unsubstituted 1,2,4-triazole compounds and excessive reactivity with fogging in the case of 3-chloro-l, 2,4-tria-25 zolverbindungen).

Specific examples of purple couplers according to the invention are listed below:

Cl

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3)

4)

5)

ch.,

N_ / 3

i n — t nh - / {\ -nh -co-ch-o- n n

W "l \ =,

cl w n cfn /

c2h5

C15H31

Cl n =

U

Cl ch.

1, -1 r ci n «K /

0 n n

Cl Cl

Cl

, ch.

N = \

P

Tnh "^ 3" n ° 2

Cl /

n n

Cl

6)

ch.

n-

/

l ^ = N Cl 0 ^ - /

.. N

- »h- / w nh-co-c3f7

n

Cl /

Cl

7)

8th)

648 938

ï- <

CH.

: N

- / ~ vnh-co-c7f15

Tm \ jr

01

.N

CH.

C5Hlltert '

// \ N

-0-1 / v.-crH ,, t ert.

Cl

NRrNH- <'^> - NH-CO- (CH2) 3-w-x / -5 "ir n

Cl ch.

w ch.

9)

10)

C5 is given

jNH - ^ - ^ - NH-C0-ÇH-0 - ^^ - C5H1] Lt ert.

! L ~ ° 2h5 ""

. Cl

9

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15)

C15H31

Cl

16)

31

Cl

The magenta couplers of the invention can be used together with a wide variety of silver halide emulsions for color photography. For example, they can be used with silver bromide, silver chloride or silver iodide emulsions or with emulsions containing a mixture of silver halides, such as emulsions with a mixture of silver bromide and silver iodide or silver chloride and silver bromide. The magenta couplers can also be used with the emulsions described in U.S. Patents 2,592,243 and 2,698,794. These magenta couplers can be used with emulsions that form an image on the surface or inside the silver halide grains, such as those described in U.S. Patent No. 2,592,250.

If the magenta couplers according to the invention are used in photographic recording material before their exposure and development, they can be incorporated directly into the emulsions before coating on the support or a layer adjacent to it.

The emulsions can also be chemically sensitized either by adding sulfur compounds, as described, for example, in US Pat. Nos. 1,574,944,1 623,469 and 2,410,689, or by adding noble metal salts, such as ruthenium, rhodium, iridium, , Palladium or platinum salts. The emulsions can also be chemically sensitized by adding gold salts, as described in US Pat. No. 2,399,083. They can also be stabilized with gold salts as described in U.S. Patents 2,597,856 and 2,587,915.

The emulsions can also be spectrally sensitized with carbocyanine dyes, for example the type described in US Pat. No. 2,503,776.

The emulsions can include organic stabilizers and antifoggants of the cyclic amine type, iminoazoles, such as mercaptobenzimidazole, triazoles, for example of the type described in US Pat. No. 2,444,608, azaindenes, for example of the type described in US Pat. Nos. 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 35 and 2 772 164 and from EJ Birr, Z. Wiss. Phot., 472 (1952), described type, tetrazoles, such as l-phenyl-5-mercaptotetrazole, thiazoles and benzothiazoles, such as 1-methylbenzothiazole and quaternary benzothiazole salts, as described, for example, in US Pat. No. 2,131,038, Mercaptobenzthiazoles, 40 such as 1-methylmercaptobenzthiazole, oxazoles, thiosemicarbazides, pyrimidines, iodonium derivatives, benzenesulfinic acids and, as inorganic stabilizers, zinc or cadmium salts of the type described, for example, in US Pat. No. 2,839,405.

45 The emulsions may also contain conventional plasticizers, such as glycerin. The emulsions can be hardened with customary hardeners for gelatin, for example aldehydes such as formaldehyde, glyoxal, succinic dialdehyde, glutaric dialdehyde or resorcylaldehyde, halogen-substituted aliphatic carboxylic acids such as mucochloric acid and mucobromic acid (cf. US Pat. No. 2,080,019) or cf. Mixtures (see U.S. Patent 2,591,542).

The emulsions can be applied with a conventional coating aid, such as saponin. The usual materials come into consideration as carrier 55, for example made of cellulose triacetate, polyesters, paper and paper coated with polyethylene. For the preparation of the silver halide dispersions which are used for the preparation of the silver halide emulsions, gelatin 60 or other water-permeable agents can be used as dispersants, for example colloidal albumin, cellulose derivatives or synthetic resins of the polyvinyl type. Such materials are described in U.S. Patents 2,286,215.2,328,808.2,322,085.2,527,872, 2,541,474.2,563,791.2,768,154,2808,331 and 2,852,382,650. If necessary, a mixture of two or more of these colloids can be used to disperse the silver halide.

The purple couplers according to the invention are either

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10th

alone or in combination with four-equivalent color couplers, particularly useful in negative type color photographic recording material using the mask technique (including mask couplers in addition to the main couplers), such as in the U.S. Patents

2 428 054.2 808 329, 2 860 975 and 2 852 370 and double layers, as described for example in GB-PS 818 687. "

In addition to the main couplers and mask couplers, other additional couplers can be used, such as those in U.S. Patents 2,689,793.2,742,832,2,998,314 and

3,227,554 couplers described.

The customary development baths can be used for the purple couplers according to the invention. These contain e.g. a developer substance of the p-phenylenediamine type, potassium bromide as a development retardant, an antioxidant such as sodium sulfite, and a base such as an alkali metal hydroxide or carbonate. You can also use a benzimidazole or its derivative, a benzothiazole or its derivative, a triazole or tetrazole or its derivative, for example a mercapto derivative, as an antifoggant, and a complexing agent for calcium ions, such as an alkali metal phosphate or an alkylenediaminoacetic acid, such as ethylenediaminetetraacetic acid, contain. Typical p-phenylenediamine developers are described, for example, in U.S. Patents 5,219,015,2,656,273 and 2,875,049 and in C.E. Kenneth Mees and T.H. James, The Theory of the Photographic Process, 3rd edition, 1966, Table 13.4, pages 294 to 295.

Examples of usable developer substances which can be used for the development of the color photographic recording material which contains the magenta couplers according to the invention are the sulfites, hydrochlorides and sulfates of a) N, N-diethyl-p-phenylenediamine; i5 b) N-ethyl-N-β-methanesulfonamidoethyl-3-methyl-4-amino-aniline;

c) N-ethyl-N-hydroxyethyl-2-methyl-p-phenylenediamine;

d) N-ethyl-N-hydroxyethyl-p-phenylenediamine and e) N, N-diethyl-2-methyl-p-phenylenediamine.

The following known purple couplers are compared to the purple couplers of the invention:

a)

ert.

Cl

B)

Cl

The examples illustrate the invention.

Examples 1 to 9

Preparation of color coupler No. 1 l- (2,4,6-trichlorophenyl) -3- [4- (a-2,4-di-tert.-amylphenoxy) -butyramido] -aniIino-4- (3-chloro- 5-methyl-1,2,4-triazolyl) -5-pyrazolone a) Preparation of ethyl a- (3-chloro-5-methyl-l, 2,4-triazolyl) acetoacetate (intermediate A)

39.5 g of ethyl a-chloroacetoacetate, 600 ml of anhydrous acetone, 28.2 g of 3-chloro-5-methyl-l, 2,4-triazole and 84 ml of triethylamine are heated under reflux for 30 hours. After cooling, the triethylamine hydrochloride is filtered off. The filtrate is evaporated under reduced pressure and the brown oily residue is extracted with diethyl ether. The ether extract is adjusted to a pH of 4 to 5 with 1 percent hydrochloric acid with shaking and then separated from the aqueous phase, dried over sodium sulfate and evaporated. The residue is fractionally distilled under 55 reduced pressure. 135 to 136 ° C / 1.5 Torr. Yield 41.5 g.

b) Preparation of a- (3-chloro-5-methyl-l, 2,4-triazolyl) malonate ethyl monothio-4-nitroanilide (intermediate product 60 product B)

53.4 g of intermediate A, 400 ml of anhydrous dimethylformamide, 39.2 g of p-nitrophenyl isothiocyanate and 30.2 g of triethylamine are heated to 60 ° C. for 16 hours. The deep red-orange colored solution obtained is then stirred into 1200 ml of 65 ice-cold 2 percent aqueous sodium carbonate solution. After about 1 hour the cloudy solution is filtered and the filtrate acidified with dilute hydrochloric acid. After standing for several hours, the clear solution is decanted and that

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obtained deep orange colored viscous oil recrystallized from aqueous methanol. Yellow crystals of mp 136 to 138 ° C. are obtained.

c) Preparation of l- (2,3,6-trichlorophenyl) -3- (4-nitroanilino) -4- (3-chloro-5-methyl-1,2,4-triazolyl) -5-pyrazolone (intermediate C )

23 g of intermediate B, 19 g of 2,4,6-trichlorophenylhydrazine and 70 ml of ethyl acetate are heated on a steam bath for 18 hours. After cooling to 50 ° C., 300 ml of methanol and 6.5 g of sodium methoxide are added, and the red-brown colored solution obtained is heated under reflux for 10 minutes. The solvent is then distilled off under reduced pressure and the residue is shaken with 30 ml of water and 100 ml of diethyl ether. The ether solution is separated off and the aqueous solution is extracted again with diethyl ether and then acidified with hydrochloric acid. The precipitated solid is filtered off on a Büchner funnel, washed with cold water, dried and recrystallized from acetonitrile. 28.4 g of yellow crystals of mp 183 ° C. (dec.) Are obtained.

d) Preparation of 1- (2,4,6-trichlorophenyl) -3- (4-amino-anilino) -4- (3-chloro-5-methyl-1,2,4-triazolyi) pyrazolone (intermediate D )

23.4 g of intermediate C are mixed with 180 ml of ethanol, 70 ml of acetic acid and 20 ml of water. The mixture is heated under reflux and carefully mixed with 25 g of iron file in small portions and then heated under reflux for a further hour. Then the still hot solution is filtered with a Büchner funnel. The filtrate is diluted with 300 ml of water and extracted with ethyl acetate. The ethyl acetate extract is evaporated under reduced pressure. The brown viscous oil obtained is recrystallized from an io mixture of acetonitrile and ethanol. 18.2 g of whitish gray crystals are obtained, which decompose at 190 ° C.

e) Preparation of the color coupler 15 9.7 g of intermediate D are suspended in 300 ml of acetonitrile. Then 6.8 g of a- (2,4-di-tert-amyl-phenoxy) butyryl chloride are rapidly added. The suspension is heated under reflux for 3 hours and then left to stand at room temperature for 24 hours. The precipitated white 20 crystals are filtered off on a Büchner funnel, washed with pure acetonitrile and dried. Yield 11.4 g.

Coupler Nos. 2 through 9 listed above are similarly prepared from the corresponding intermediates. The melting points and analysis values of the coupling are summarized in Table I.

Dye-found couplers

No. F., ° C C% H% N%

1

220-222

57.70

5.48

12.48

2nd

159-163

56.84

5.48

11.85

3rd

108-112

60.34

6.15

11.33

4th

157-159

57.86

5.52

12.38

5

183 dee

42.03

2.18

19.08

6

223-225

38.73

1.79

14.42

7

224-226

35.57

1.40

11.21

8th

152-155

63.90

6.63

12.95

9

160-165

64.06

6.62

13.01

Table I

calculated

ci% c% h% n% ci%

18.08

57.95

5.50

12.44

18.00

17.38

57.29

5.55

11.99

17.34

16.49

60.21

6.23

11.43

16.54

17.95

57.95

5.50

12.45

18.01

27.44

41.97

2.15

19.03

27.53

20.68

38.79

1.78

14.39

20.82

16.08

35.44

1.37

11.12

16.09

9.41

64.33

6.61

13.13

9.50

9.55

64.33

6.61

13.13

9.50

Example 10

An orthochromatically sensitized silver bromide-silver-iodide negative emulsion is mixed with two-equivalent purple coupler No. 3 in an amount of 83.13 mmol / mol Ag. The finished emulsion is then applied to a cellulose triac in a silver surface application of 1.1 g / m 2.

The same emulsion is mixed with the four-equivalent pure-pure coupler A in an amount of 41.56 mmol / mol Ag. The finished emulsion is applied in the same way to a cellulose triacetate support with a surface area of 2.2 g / m2.

The sensitometric samples obtained are then subjected to an accelerated incubation for 10 days at 38 ° C. and 75% relative atmospheric humidity. At the end of this incubation, the samples are exposed with a sensitometer with a 0.30 log it step wedge at a color temperature of 5500 ° K together with corresponding samples incubated under room conditions. All samples are then developed simultaneously in a standard developer bath for color negative films and finally measured with an automatic densitometer. The following results are obtained:

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12

Color coupler

Dmax

Dmax

Room conditions

10 days, 38 ° C,

75% clean. F.

3rd

1.35

1.31

A

1.47

0.92

Example 11

Two double layer films are made as follows.

Film 1 (invention)

A medium sensitivity silver bromide-silver iodide negative emulsion which is orthochromatically sensitized is mixed with the No. 4 two-equivalent magenta coupler in an amount of 68.6 mmol / mol Ag and with the mask coupler B in an amount of 12.4 mmol / mol Ag transferred. The emulsion obtained is applied to a cellulose triacetate support in an area application of 1.4 g of silver / m 2.

An orthochromatically sensitized silver bromide-silver-iodide negative emulsion of high sensitivity is mixed with the two-equivalent magenta coupler 4 in an amount of 5.41 mmol / mol Ag and with the purple mask coupler B in an amount of 1.67 mmol / mol Ag. This highly sensitive emulsion is then applied to the medium sensitivity layer in an area application of 1.4 g silver / m2.

Finally, a protective gelatin layer is applied over the second layer.

Film 2 (comparison)

Similar to Film 1, an orthochromatically sensitized medium sensitivity silver bromide-silver iodide negative emulsion is mixed with the four-equivalent magenta coupler A in an amount of 34.3 mmol / mol Ag and with the magenta mask coupler in an amount of 6.2 mmol / mol Ag. The emulsion obtained is then applied to a cellulose triacetate support in an area application of 2.2 g of silver / m 2.

An orthochromatically sensitized silver bromide-silver-iodide negative emulsion of high sensitivity is mixed with the four-equivalent purple coupler A in an amount of 1.67 mmol / mol Ag and with the purple mask coupler B in an amount of 1.67 mmol / mol Ag. This emulsion is then applied to the medium sensitivity layer in an area application of 1.4 g silver / m2. Finally, a protective gelatin layer is applied over the second layer.

A sample of the two films is then exposed with a sensitometer with a 0.30 log it step wedge at a color temperature of 5500 ° K and developed with a standard developer for color negative films. The results are shown in Fig. 1. The dashed line corresponds to film 1, the solid line corresponds to film 2.

The present invention also relates to the reaction of the a-triazolyl-thiomalonanilide with the phenylhydrazine. In this process, an a-triazolylthioma lonanilide is reacted with a phenylhydrazine which is halogen-substituted in the benzene ring. Other substituents, for example alkyl or alkoxy radicals or a fused-on benzene ring to form a naphthyl group, may be present on the benzene ring in addition to the halogen atom. Preferred are o-halogen substituents, for example 2-, 2,4- and 2,4,6-halo-substituted phenylhydrazines. Other substituents besides the halogen atoms are C] _3-alkyl radicals, especially methyl groups, which are preferably in the o- and p-positions.

The process for the preparation of the 5-pyrazolone color couplers of the invention which are substituted by a benzamide group proceeds as follows:

1) reaction of an a-halogen-a-carbalkoxyacetamide with a 1,2,4-triazole in the presence of a base;

2) reaction of the a-triazolyl-a-carbalkoxy-acetamide obtained with phosphorus pentasulfide;

3) reaction of the a-triazolyl-a-carbalkoxy-thioacetamide obtained with a substituted hydrazine and

4) Cyclization of the hydrazone obtained with a sodium alcoholate.

This procedure is explained below.

Example 12

Preparation of Color Coupler No. 10 l- (2,4,6-trichlorophenyl) -3- [3-a- (2,4-di-tert-amylphenoxy) acetamido-benzamido] -4- (3-chloro 1,2,4-triazolyl) -5-pyrazolone a) Preparation of a-bromo-a-carbäthoxyacetamid (intermediate A)

A solution of 150 g (1.144 mol) of a-carbäthoxyacet-amide in 1800 ml of methylene chloride is added dropwise and with stirring at 20 to 30 ° C with a solution of 182.7 g (1.144 mol) of bromine in 200 ml of methylene chloride. When the addition is complete, the mixture is stirred for a further hour at room temperature and then 500 ml of water are added with vigorous stirring. The organic phase is separated off, dried over calcium chloride and then evaporated under reduced pressure. The residue is dissolved in 200 ml of ethyl acetate. The solution is poured into 1000 ml of heptane. The resulting precipitate is filtered off. 175 g of a gray solid of melting point 56 to 58 ° C. are obtained.

b) Preparation of a- (3-chloro-l, 2,4-triazolyl) -a-carbäthoxy-acetamide (intermediate B)

A cold solution of 80 g of intermediate A and 44 g of 3 (5) -chloro-2,4,4-triazole in 750 ml of acetone is mixed with 33.5 g of powdered sodium hydroxide. The mixture is stirred at room temperature for 2 hours, then neutralized with hydrochloric acid and filtered. The filtrate is evaporated under reduced pressure and the residue is recrystallized from water. 54 g of white crystals of mp 108 to 110 ° C. are obtained.

c) Preparation of a- (3-chloro-l, 2,4-triazolyl) -a-carbäthoxy-thioacetamide (intermediate C)

A solution of 46 g (0.2 mol) of intermediate B in 300 ml of anhydrous dioxane is mixed with 11.1 g (0.05 mol) of phosphorus pentasulfide. The mixture is heated under reflux for 2 hours, cooled and filtered. The filtrate is evaporated under reduced pressure. The oily residue is used in the next step without further purification.

d) Preparation of l- (2,4,6-trichlorophenyl) -3-amino-4- (3-chloro-l, 2,4-triazolyl) -5-pyrazolone (intermediate D)

Intermediate B is mixed with 53 g (0.25 mol) of 2,4,6-trichlorophenylhydrazine and 150 ml of ethyl acetate and heated under reflux for 18 hours. The solvent is then distilled off under reduced pressure. A solution of 21.1 g (0.4 mol) of sodium methoxide in 400 ml of pure methanol is added to the residue. The solution is heated under reflux for 15 minutes and then stirred into 2000 ml of cold water. The pH of the solution is adjusted to about 8 with dilute hydrochloric acid. The resulting solid precipitation is sucked off on a filter and with

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648 938

Washed water. The solution is acidified against litmus with dilute hydrochloric acid. The resulting solid precipitate is filtered off, washed with cold water, dried and digested with boiling acetonitrile. 42.5 g of product of F. 235 ° C are obtained.

e) Preparation of l- (2,4,6-trichlorophenyl) -3- (3-nitrobenzamido) -4- (3-chloro-1,2,4-triazolyl) -5-pyrazolone (intermediate E)

37.1 g (0.098 mol) of intermediate D, 500 ml of acetonitrile and 27.2 g (0.147 mol) of m-nitrobenzoyl chloride are heated under reflux for 90 minutes. The solvent is then filtered off under reduced pressure and the residue is stirred with 300 ml of cold 3 percent sodium hydroxide solution. The cloudy solution obtained is filtered and acidified with concentrated hydrochloric acid. The resulting solid is filtered off, washed with water, dried and digested with boiling acetonitrile. The product is obtained as a light yellow-brown solid with a melting point of 245 ° C. (dec.).

f) Preparation of l- (2,4,6-trichlorophenyl) -3- (3-aminobenz-amido) -4- (3-chloro-1,2,4-triazolyl) -5-pyrazolone (intermediate F)

26.4 g of intermediate E are dissolved in 250 ml of ethylene glycol dimethyl ether and hydrogenated in the presence of Raney nickel at 50 ° C. with hydrogen at a pressure of 20 at. After cooling, the catalyst is filtered off and the solvent is distilled off under reduced pressure. The solid residue is extracted with boiling ethanol and filtered. 18 g of a white solid of mp 252 ° C. are obtained.

Manufacture of the color coupler

5 g (0.01 mol) of intermediate F, 50 ml of acetonitrile and

3 g of a- (2,4-di-tert-amylphenoxy) acetyl chloride are heated under reflux for 2 hours. The solution is then poured into cold water. The resulting white precipitate is filtered off, washed with cold water, dried and recrystallized from a mixture of ethyl acetate and acetonitrile; F. 215 ° C.

Example 13

Preparation of color coupler No. 16 io 1 - (2,4,6-trichlorophenyl) -3- [a- (m-pentadecylphenoxy) -butyramido] -4- (3-chloro-1,2,4-triazolyl) -5 -pyrazolone

10 g of intermediate D, 125 ml of acetonitrile and 16.1 g of a- (m-pentadecylphenoxy) butyryl chloride are heated under reflux for 3 hours. The solvent is then distilled off under reduced pressure and the residue is dissolved in 100 ml of ethyl acetate. The solution is stirred vigorously with cold 10% sodium hydroxide solution for 10 minutes. After neutralization with hydrochloric acid, the organic phase is separated off, washed with water and evaporated. The residue is recrystallized from a 1: 1 mixture of ethyl acetate and acetonitrile. 18.2 g of a white solid of melting point 201 to 203 ° C. are obtained.

All benzamide color couplers of the formulas given above are produced by the general procedure described above.

A comparison of these color couplers with color couplers with 3,5-dialkyl or 3,5-dichloro substitution on the 1,2,4-triazole group shows a considerable improvement. The dialkyl- and dichloro-substituted color couplers either show high haze values, excessive reactivity and / or undesirable contrast. The color couplers of the invention, particularly the 3-chloro-1,2,4-triazole compounds with or without substitution in the 5-position, have excellent properties in this regard.

c;

1 sheet of drawings

Claims (10)

648 938 2nd PATENT CLAIMS 1. Two-equivalent magenta couplers with a 5-pyrazolone ring and a) in the 1-position a phenyl group substituted by at least one halogen atom, b) in the 3-position an anilino or amide group and c) in the 4-position a 1,2,4-triazole group of the general formula i " Il I n c in which R is a hydrogen atom or a Ci_3-alkyl radical and R1 is a chlorine atom or a C (_3-alkyl radical, where R and R1 are not simultaneously alkyl radicals. 2. Purple coupler according to claim 1, characterized in that R represents a methyl group. 3. Purple coupler according to claim 1 and 2, characterized in that they have at least one terminal, diffusion resistance imparting aliphatic chain, which at least one position of the benzene core of the anilino lo or amide group is bound. 4. Purple coupler according to claim 1 of the general formula Ia in which R is a hydrogen atom or a C [_3-alkyl radical, R2 is a chlorine atom and R3 and R4 are chlorine atoms or C ^ -alkyl or Ci_3-alkoxy radicals, m has the value 0 or 1 , n has the value 0 or 1, but is not greater than m, R5 is a Ci ^ alkylene or a C ^ alkylene oxide group with an oxygen atom bonded to the benzene ring, R6 is a hydrogen atom or a Ci_25 alkyl or C ^ s Alkoxy radical and R7 and R8 are hydrogen atoms, Ci_25-alkyl or C, _25-alkoxy radicals or phenoxyalkyleneamido groups, where R6, R7 and R8 are selected such that only one of the radicals R6 and R7 and only one of the radicals R7 and R8 are different at the same time Has meaning as a hydrogen atom. 5. Purple coupler according to claim 4, characterized in that R3 and R4 represent chlorine atoms, m has the value 1 and n has the value 0 and R7 represents a phenoxyalkylene amido group. 6. Purple coupler according to claim 5, characterized in that R7 represents a phenoxybutyramido group. 7. Purple coupler according to claim 6, characterized in that the radical R7 has at least one alkyl radical in the m or p position of the phenoxy group. 8. Process for the preparation of new two-equivalent magenta couplers with a 5-pyrazolone ring and a) in the 1-position a phenyl group substituted by at least one halogen atom, b) in the 3-position an anilino or amide group and c) in the 4-position a 1,2,4-triazole group of the general formula R c N " Ii n - 35 in which R is a hydrogen atom or a C | _3-alkyl radical and R1 is a chlorine atom or a C | _3-alkyl radical, where R and R1 are not simultaneously alkyl radicals, by a) reacting an alkyl a-haloacetoacetic acid with a corresponding 1,2, 4-triazole in the presence of a 4o nitrogenous organic base and an organic solvent, b) reaction of the a-triazolylacetoacetic acid alkyl ester obtained with a phenyl isothiocyanate and c) reaction of the a-triazolylthiomalonanilide obtained 45 with a corresponding halogen-substituted phenylhydrazine and cyclization of the hydrazone obtained, characterized in that the reaction (c) is carried out in the presence of an alkyl carboxylic acid as a solvent. 9. color photographic recording material, characterized in that it contains a purple coupler according to claim 1 in at least one of the silicon halide emulsion layers. 10. Color photographic recording material according to claim 9, characterized in that it is the purple Contains 55 couplers dissolved in a high-boiling organic solvent. cv