CS236794B2 - Processing of 1,4-diketopyrrolo-(3,4--)pyrrol - Google Patents

Description

The invention relates to a process for the preparation of 1,4-diketopyrrolo [3,4-c] pyrroles which are valuable pigments. Tetrahedron Lett., 1947, pp. 2549-2552 describes a process for the preparation of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole from benzonitrile and ethyl ester. bromoacetic acid in the presence of an activated zinc-copper system. However, the yields obtained so far are insufficient. If, on the other hand, succinic acid ester and aromatic nitrile are chosen as the starting material, the desired pyrrolo [3,4-c] pyrrole pigment is obtained in substantially higher yields under certain reaction conditions. In addition, novel pyrrolo [3,4-c] pyrroles are obtained by the process according to the invention, which are not prepared by the known methods or are difficult to prepare by the known methods.

The invention therefore relates to a process for the preparation of 1,4-diketopyrrolof 3,4-c] pyrroles of the general formula I

where it means

R1 and R2 independently of one another are an isocyclic or heterocyclic group,

R 1 and R 2 independently of each other optionally substituted phenyl, naphthyl, diphenylyl, pyridyl, furanyl or thiophenyl group, characterized in that 1 mol of symmetrical or asymmetric dialkyl succinate, diaryl succinate or dicyclohexyl succinate is reacted with alkyl moiety contains 1 to 18 carbon atoms and an aryl moiety of 6 to 10 carbon atoms, with 2 moles of nitrile of the general formula

R1 - CN (Π) or

Rz — CN (ΙΠ) where

R 1 and R 2 are as defined above, or with 1 mole of nitrile of formula (I), 1 mole of nitrile of formula (III) in an organic solvent in the presence of a C 1 -C 10 alkali alcoholate as a strong base at tep236794

230794, 60 ^° C to 140 ^° C, and liberates the compound of formula I from the hydrolysis reaction product.

R1 and R2 may have the same or different meanings, but preferably have the same meaning. They represent a phenyl group, a diphenyl group, a naphthyl group, a pyridyl group, a furanyl group or a thiophenyl group. These groups may have conventional substituents that do not cause water solubility such as:

benzoxazolyl, dibenzfuranyl, benzothiophenyl, dibenzothiofenylová, indolyl, carbazolyl, pyrazolyl, imidazolyl, oxazolyl, isoxazolyl, thiazolyl, indazolyl, benzthiazolyl, pyridazinyl quinolyl, quinazolyl, quinoxalyl, phthalazinyl, ftalazindionylová, ftalamidyíová, chromonylová, naftolaktamylová, chinolonylová, imidylová ortho-sulfobenzoic acid , maleimidimidyl, naphtharidinyl, benzimidazolonyl, benzoxazolonyl, benzthiazolonyl, benzthiazothionyl, quinazolonyl, quinoxalonyl, phthalazonyl, dioxopyrimidinyl, pyridonyl, isoquinolonyl, isoquinolinyl. isothiazolyl, benzisoxazolyl, benzisothiazolyl, indazolonyl, acridinyl, acronyl, quinazolindionyl, benzoxazinonyl, quinoxalidionyl, benzoxazindionyl and naphthalimidyl. Both isocyclic and heterocyclic aromatic groups may have common substituents that do not cause water solubility, such as:

(1) halogen atoms such as chlorine, bromine or fluorine;

2) branched or unbranched alkyl groups preferably having 1 to 18 carbon atoms and in particular 1 to 12 carbon atoms and in particular 1 to 8 carbon atoms and most preferably 1 to 4 carbon atoms. These alkyl groups may have substituents not causing water solubility such as fluorine, hydroxy, cyano, -OCOR 3, -OR 4, -COOR 3, -CONR 4 R 5 or -R 3 -OCONHR 3 where R 3 is alkyl, aryl such as naphthyl or optionally a halogen atom, an alkyl group or a -O-alkyl substituted benzyl group or a heterocyclic group, R 1 and R 5 are hydrogen, respectively. cyano or hydroxy-substituted alkyl, C 5 -C 6 -cycloalkyl, aryl or heteroaryl, especially optionally substituted with C 1 -C 6 -cycloalkyl. a halogen atom, an alkyl group or a -O-alkyl-substituted phenyl group, or R 4 and R 5 together with the nitrogen atom form a 5- to 6-membered heterocyclic ring, such as a morpholine, piperidine or phthalimide ring. Further possible substituents of the alkyl groups are monoalkylated or dialkylated amino groups, aryl groups such as naphthyl or especially optionally halogen, alkyl or O-alkyl substituted phenyl or further heterocyclic aromatic groups such as 2-thienyl, 2-benzoxazolyl 2-benzthiazolyl, 2-benzimidazolyl, 6-benzimidazolonyl, 2-pyridyl, 3-pyridyl or 4 pyridyl, 2-quinolyl, 4-quinolyl or 6-quinololyl.

If the substituents referred to in (2) themselves contain an alkyl group, the alkyl group may be straight or branched and preferably contains 1 to 18 carbon atoms, in particular 1 to 12 carbon atoms, in particular 1 to 8 carbon atoms and most preferably 1 to 4 atoms carbon.

Examples of unsubstituted or substituted alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-amyl, n-pentyl, n-hexyl, 1,1 3,3-tetramethylbutyl, n-heptyl, n-octyl, nonyl, decyl, undecyl, dodecyl, hydroxymethyl, trifluoromethyl, trifluoroethyl, cyanomethyl, methoxycarbonylmethyl, acetoxymethyl or benzyl.

A group of the formula -OR 6 wherein R 6 represents a hydrogen atom, an alkyl group, an aryl group, for example a naphthyl group or particularly optionally a halogen atom, an alkyl group or an -O-alkyl substituted phenyl group, a C 5 -C 6 cycloalkyl group, an aralkyl group or heterocyclic group. The alkyl group as a moiety of the group R < 2 > has the specified number of carbon atoms indicated as preferred. Examples of the group R6 include methyl, ethyl, n-propyl, isopropyl, trifluoroethyl, phenyl, O'-chlorophenyl, m-chlorophenyl or p-chlorophenyl, o-methylphenyl, m-methylphenyl or p-methylphenyl, alpha - naphthyl or beta-naphthyl, cyclohexyl, benzyl, thienyl or pyranylmethyl.

4) A group of the formula -SR 6, wherein R e is as defined in paragraph 3). Examples of R 6 are methyl, ethyl, n-propyl, isopropyl, phenyl, o-chlorophenyl, m-chlorophenyl or p-chlorophenyl, o-methylphenyl, m-methylphenyl or p-methylphenyl, alpha-naphthyl or beta naphthyl, cyclohexyl, benzyl, thienyl or pyranylmethyl.

5) Cyano group.

6} A group of the formula -NR 4 R 5 wherein R 4 and R 5 are as defined in paragraph 2}.

Examples are amino, methylamino, dimethylamino, ethylamino, diethylamino, isopropylamino, beta-hydroxyethylamino, beta-hydroxypropylamino, Ν, Ν-bis- (beta-hydroxyethyl) amino, Ν, Ν-bis- (beta-cyano), cyclohexylamino, phenylamino, N-methylphenylamino, benzylamino, dibenzylamino, piperidyl or morpholyl.

7) A group of the formula -COOR 3 wherein R 3 is as defined in paragraph 2). Examples of R3 are methyl, ethyl, isopropyl, tert-butyl, n-butyl, phenyl, benzyl and furfuryl.

8) A group of the formula -COR 6 wherein R 6 is as defined in paragraph 3). Examples are methyl, ethyl, tert-butyl, phenyl, o-chlorophenyl, m-chlorophenyl or p-chlorophenyl, o-methylphenyl, m-methylphenyl or p-methylphenyl or alpha-naphthyl and beta-naphthyl group.

9) A group of the formula -NR 7 COR 3 wherein R 3 is as defined in paragraph 2) and R 7 represents a hydrogen atom, an alkyl group, an aryl group such as a naphthyl group or particularly optionally a halogen atom, alkyl group or O-alkyl substituted phenyl group, C5 -C6-cycloalkyl, aralkyl or -COR3 wherein the two COR3 groups together with the nitrogen atom may form a heterocyclic ring. The alkyl radical R 7 in paragraph 2] has the preferred number of carbon atoms indicated. Examples are acetylamino, propionylamino, butyrylamino, benzoylamino, p-chlorobenzoylamino, p-methylbenzoylamino, N-methylacetylamino, N-methylbenzoylamino, N-succinimido and N-phthalimido.

10) A group of the formula -NR 6 COOR 3 wherein R 3 and R 6 are as defined in 2) and 3). Examples are groups of the formula

-NHCOOCH 3, NHCOOC 2 H 5 and NHCOOC 6 H 5.

lij A group of the formula -NR 6 CONR 4 R 5 wherein R 6, R 5 and R 4 are as defined in (3) and (2) above. Examples which may be mentioned are ureido, N-methylureido, N-phenylureido or N, N-2 ‘, 4‘-diinethylphenylureido.

j A group of formula -NHSO 2 R 3, wherein R 3 is as defined in (2).

Examples are methylsulfonylamino, phenylsulfonylamino, p-toluylsulfonylamino or beta-naphthylsulfonylamino.

J A group of the formula -SO 2 R 3 or SOR 3 wherein R 3 is as defined in (2). Examples are methylsulfonyl, ethylsulfonyl, phenylsulfonyl, 2-naphthylsulfonyl and phenylsulfoxidyl.

14) A group of formula (SO2OR3, wherein R3 is as defined in paragraph 2. Examples of R3 include methyl, ethyl, phenyl, o-chlorophenyl, m-chlorophenyl, or p-chlorophenyl, o-methylphenyl, m- methylphenyl or p-methylphenyl, alpha-naphthyl or beta-naphthyl.

15) A group of the formula -CONR 4 R 5 wherein R 4 and R 5 are as defined in (2). Examples are carbamoyl, N-methylcarbamoyl, N-ethylcarbamoyl, N-phenylcarbamoyl, N, N-dimethylcarbamoyl, N-methyl-N-phenylcarbamoyl, N-alpha-naphthylcarbamoyl or N-piperidylcarbamoyl.

16) A group of the formula -SO 2 NR 4 R 5, wherein R 1 and R 5 are as defined in paragraph 2). Examples are sulfamoyl, N-methylsulfamoyl, N-ethylsulfamoyl, N-phenylsulfamoyl, N-methyl-N-phenylsulfamoyl and N-morpholylsulfamoyl.

J A group of the formula N-N-R e wherein R a is a coupling component or optionally a halogen atom, an alkyl group or an -O-alkyl group substituted by a phenyl group. The alkyl moiety in the group R5 has the preferred number of carbon atoms indicated in (2). Examples of R 5 include acetoacetarylide, pyrazolyl, pyridonyl, o-hydroxyphenyl or p-hydroxyphenyl, o-hydroxynaphthyl, p-aminophenyl or p-N, N-dimethylaminophenyl.

18] A group of the formula -OCOR 3 wherein R 3 is as defined in paragraph 2). Examples of R 5 include methyl, ethyl, phenyl, o-chlorophenyl, m-chlorophenyl, m-chlorophenyl or the like. p-chlorophenyl.

19) A group of the formula -OCONHR 3 wherein R 3 is as defined in paragraph 2). Examples of R3 include methyl, ethyl, phenyl, o-chlorophenyl, m-chlorophenyl, and p-chlorophenyl.

Preferably, the process of the present invention uses a single nitrile of formula (II) or (III) as a starting material for the preparation of compounds of formula (I). Preference is also given to using nitriles of the general formula IIa and / or III, in which R1 and R2 are unsubstituted phenyl or naphthyl or phenyl or naphthyl substituted by a substituent not causing water solubility.

In particular, nitriles of the formula IV are used as starting materials

where it means

R 9, R 10 and R 11 independently of one another are hydrogen, fluorine, chlorine or bromine, carbamoyl, cyano, trifluoromethyl, alkylcarbamoyl of 2 to 13 carbon atoms in the alkyl moiety, alkyl of 1 to 12 carbon atoms, alkoxy of 1 C 1 -C 12 alkylmercapto, C 2 -C 13 alkoxycarbonyl, C 2 -C 13 alkanoylamino, C 1 -C 12 monoalkylamino, C 2 -C 24 dialkylamino , optionally halogen, C 1 -C 12 alkyl or C 1 -C 12 alkoxy substituted phenoxy, phenyl mercapto, phenoxycarbonyl, phenyicarbamoyl or benzoylamino, wherein at least one of R 9, R 10 and R 11 is hydrogen.

In particular, nitriles of the general formula V are used as starting materials

(V) wherein) one of R 12 and R 13 is chlorine, bromine, C 1 -C 4 alkyl, cyano, C 1 -C 4 alkoxy, optionally chlorine or methyl-substituted phenoxy, carbamoyl, alkylcarbamoyl having 2 to 5 carbon atoms in the alkyl moiety, optionally a chlorine atom, a methyl or methoxy-substituted phenylcarbamoyl group and a second hydrogen atom.

The diesters of succinic acid used may be dialkyl or dicyclohexyl esters, and the dialkyl succinates may also be unsymmetrical. However, symmetrical diesters of succinic acid, in particular symmetrical dialkyl succinates, are preferably used. In the case of the diaryl ester of succinic acid, the aryl moiety is especially unsubstituted or halogen such as chlorine, C1 -C6 alkyl such as methyl, ethyl, isopropyl or tert-butyl or C1 -C6 alkoxy such as methoxy or ethoxy substituted phenyl. The aryl moiety is preferably an unsubstituted phenyl group. In the case of a dialkyl ester, the alkyl moiety is unbranched or branched, but is preferably branched and preferably contains 1 to 18 carbon atoms, especially 1 to 12 carbon atoms, especially 1 to 8 carbon atoms, and most preferably 1 to 5 carbon atoms. The branched alkyl moiety is preferably a secondary or tertiary alkyl group such as isopropyl, sec-butyl, tert-butyl, tert-amyl and dicyclohexyl.

Examples of diesters of succinic acid are: dimethyl ester, diethyl ester, dipropyl ester, dibutyl ester, dipentyl ester, dihexyl ester, diheptyl ester, dioctyl ester, diisopropyl ester, di-sec-butyl ester, di-tert-butyl ester, di-tert-butyl ester, di-tert. , 1-dimethylbutyl ester, di- (1,1,3,3-tetramethyibutyl) ester, di- (1,1-dimethylpentyl) ester, di- (1-methyl-1-ethylbutyl) ester, di- 1-dimethylpropyl) ester, diphenyl ester, di- (1,1-diethylpropyl ester), di (4-methylphenyl) ester, di- (2-methylphenyl) ester, dl- (4-chlorophenyl) ester, and dicyclohexyl succinate.

The diesters of succinic acid and the nitriles of the formulas II and III are known compounds and can be prepared by methods known per se.

The reaction of the diesters of succinic acid with nitrile is carried out in an organic solvent. Suitable organic solvents are, for example, primary, secondary and tertiary alcohols having 1 to 10 carbon atoms, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-pentanol, 2- methyl-2-butanol, 2-methyl-2-pentanol, 3-methyl-3-pentanol, 2-methyl-2-hexanol, 3-ethyl-3-pentanol, 2,4,4-trimethyl-2-pentanol or glycols, such as ethylene glycol or diethylene glycol, and an ether, such as tetrahydrofuran or dioxane, or glycol ethers, such as ethylene glycol methyl ether or diethylene glycol monoethyl ether, ethylene glycol ethyl ether, or diethylene glycol monoethyl ether, dipolar aprotic solvents such as acetonitrile, dimethylformamide, benzonitrile, nitrobenzene, N-methylpyrrolidone, aliphatic or aromatic hydrocarbons such as benzene, optionally substituted by alkyl, alkoxy or halogen atoms such as toluene, xylene, anisole or chlorobenzene, or aromatic N-heterocyclic compounds such as pyridine, picoline or quinoline. Addition

23B794 it is also possible to use the irritiles of formula (II) and (III) simultaneously as solvents in cases where these nitriles are liquid in the temperature range at which the reaction is carried out. The solvents may also be used in the form of mixtures. Suitably 5 to 20 parts by weight of solvent are used per 1 part by weight of the reactants.

In the process according to the invention, an alcohol, in particular a secondary or tertiary alcohol, is preferably used as the solvent. Suitable tertiary alcohols are tert-butanol or tert-amyl alcohol. Mixtures of these preferred solvents with aromatic hydrocarbons such as toluene or xylene or benzene substituted with halogen atoms such as chlorobenzene are also of great importance.

The process of the invention is carried out in the presence of a strong base. Suitable strong bases are, in particular, alkali metals such as lithium, sodium or potassium, or alkaline earth metal alkoxides or alkali metal alcoholates which are especially derived from primary, secondary or tertiary aliphatic alcohols having 1 to 10 carbon atoms, such as methylate , ethylate, n-propylate, isopropylate, n-butylate, sec-butylate, tert-butylate, 2-methyl-2-butylate, 2-methyl-2-pentylate, 3-methyl-3-pentylate, 3-ethyl Lithium, sodium or potassium -3-pentylate. However, mixtures of the abovementioned bases may also be used.

In the process according to the invention, the alkali metal alcoholate is preferably used as a strong base, the alkali metal being in particular sodium or potassium and the alcoholate preferably derived from a secondary or tertiary alcohol. Thus, particularly preferred strong bases are, for example, sodium or potassium isopropylate, sec-butylate, tert-butylate and tert-amylate, respectively, of sodium or potassium. The alkali metal alcoholates can also be prepared in situ by reacting the corresponding alcohol with an alkali metal, reacting the corresponding alcohol with an alkali metal, an alkali metal hydride or an alkali metal amide.

In the process according to the invention, the strong bases can be used in an amount of, in particular, 0.1 to 10 mol, preferably 1.9 to 4.0 mol, based on 1 mol of the succinic diester introduced. Although in principle a stoichiometric amount of base is sufficient, in many cases excess base has a beneficial effect on the yield of the reaction. '

The process according to the invention is carried out in particular at a temperature of 60 to 140 ° C, preferably at a temperature of 80 to 120 ° C.

Water, a C1-C4 alcohol such as methanol, ethanol, but preferably aliphatic or aromatic carboxylic or sulfonic acids such as formic acid, acetic acid, propionic acid, oxalic acid may be used to hydrolyze the condensation product. benzoic or benzenesulfonic acid. In addition, mineral acids such as hydrochloric, sulfuric or phosphoric acid are also suitable as acids. Preferably, organic acids are used for the hydrolysis, in particular aliphatic carboxylic acids such as acetic acid.

In hydrolysis, the compound of formula (I) is precipitated and can be isolated by filtration.

For the reaction of the succinic diester with the nitriles of the formulas II to V, it is in principle possible to introduce all components at a lower temperature and then heat the mixture to the reaction temperature range or to add the individual components in the reaction temperature range in any desired sequence. In a preferred embodiment, which is generally advantageous in yield, the nitrile is introduced together with the base and the succinic diester is added at the reaction temperature. Furthermore, it is possible to simultaneously add the diester of succinic acid and nitrile to the present base. It is also possible to carry out the process according to the invention in batches but not continuously.

Especially in the case of succinic diester with lower alkyl moieties and in the case of alcohols derived from lower alcohols, such as methanol, ethanol, n-propanol, isopropanol or tert-butanol, it may be necessary to remove the lower alcohol formed during the reaction ^. to achieve higher reaction yields.

When an alcohol is used as the solvent and the alcoholate base is preferred, it may be advantageous to choose an alcohol and an alcoholate with the same alkyl moiety. It may also be advantageous if the diester of succinic acid also contains the same alkyl moieties.

A further preferred embodiment of the process according to the invention is based on the addition of nitrile in a quantity greater than stoichiometric to the diester of succinic acid. Indeed, it has been shown that with an excess of nitrile with respect to the succinic diester, the optimum amount being dependent on the respective components and may be up to 10 times the stoichiometrically required amount with respect to the succinic diester, the yields of the final product can generally still be increased. Excess nitrile can generally be recovered. In many cases, an excess of succinic diester with respect to the nitrile may have a positive effect on the yield of the reaction, and the excess may be up to twice the stoichiometrically required amount of succinic diester.

The compounds of the formula I prepared according to the invention are novel when R1 and R2 are aromatic N-heterocyclyl residues. These N-heterocycles may be unsubstituted or substituted by a halogen atom, a cyano group, a carbamoyl group, a trifluoromethyl group, an alkyl group or an alkoxy group, each alkyl or alkyloxy moiety each containing up to 18 carbon atoms, preferably 1 to 8 carbon atoms and especially 1 to 8 carbon atoms. 4 carbon atoms. R1 and R2 may be, for example, pyridine residues, but preferably o-pyridyl, m-pyridyl or p-pyridyl.

Depending on the type of substituents and the dyed polymers, the compounds of the formula I can also be used as polymer-soluble dyes. However, as a rule, the compounds of formula I are used as pigments for high molecular weight organic materials. The pigments can be used directly in the form obtained by the process according to the invention.

Depending on the purpose of use, the pigments prepared by the process according to the invention can be converted into a more opaque or transparent form.

In order to achieve a transparent form, the hydrolysis is preferably carried out at lower temperatures (below 80 ° C).

In the case where a pigment with a higher hiding power is desired, it is expedient to carry out the hydrolysis at higher temperatures (above 80 ° C), optionally under pressure, it is also possible to isolate the pigment after hydrolysis first and then heated in water or in an organic solvent, optionally under pressure to obtain a mold with greater hiding power. Preferably, organic solvents boiling above 80 ° C are used. Particularly suitable solvents are halogen atoms, benzenes substituted with alkyl or nitro groups, such as xylols, chlorobenzene, o-dichlorobenzene or nitrobenzene, as well as pyridine bases such as pyridine, picoline or quinoline, ketones such as cyclohexanone, ethers such as ethylene glycol monomethyl ether or ethylene glycol monoethyl ether, amides such as dimethylformamide or N-methylpyrrolidone, as well as dimethyl sulfoxide or sulfolane. The post-treatment can also be carried out in water in the presence of organic solvents and / or with the addition of surfactants.

Depending on the purpose of use, it may be advantageous to prepare mixtures of the compounds of the formula I. This can be achieved, for example, by mixing the various reaction solutions independently of each other before hydrolysis, hydrolyzing and recovering them together. It is also possible to precipitate two or more compounds of the formula I together.

High molecular weight compounds which can be colored or pigmented with compounds of formula I are, for example, cellulose ethers and esters such as ethylcellulose, nitrocellulose, cellulose acetate, cellulose butylate, natural or artificial resins such as polymer and condensation resins, for example aminoplasts, in particular however, urea-formaldehyde and melamine-formaldehyde resins, alkyd resins, phenoplasts, polycarbonates, polyolefins such as polystyrene, polyvinyl chloride, polyethylene, polypropylene, polyacrylonitrile, polyacrylic acid ester, polyamides, polyurethanes or polyesters, rubber, silicone, casein, casein, casein, casein, or in mixtures.

It is of no significance here whether the high molecular weight organic compound is in the form of a plastic, a melt or in the form of a dope, lacquers, paints or inks. Depending on the application, it is preferable to add the pigments of the formula I as tinting agents or in the form of preparations. Based on the pigmented high molecular weight organic material, the compound of the formula (Ϊ) is used in an amount of 0.1 to 10% by weight.

The dyeings obtained, for example plastics, fibers, lacquers or prints, are distinguished by high color strength, good dispersibility, good varnish stability, resistance to migration, heat and light and water resistance as well as good gloss.

The following examples illustrate the invention.

He did

If possible, an anhydrous mixture of 48.2 ml of t-amyl alcohol, 17.3 g of potassium t-butylate and 72.2 g of benzonitrile is heated to about 98 ° C under a nitrogen atmosphere. Once this temperature is reached, an anhydrous solution of 7.31 g of dimethyl succinate in 5.0 ml of tert-amyl alcohol is preferably added over 145 minutes via a metering pump. The temperature is maintained at 98-99 ° C. The methanol formed is distilled off. After the addition was complete, the reaction mixture was maintained at 99 ° C for two hours. It is then cooled to 65 ° C, slowly diluted with 100 ml of methanol, slowly neutralized with 10.8 ml of glacial acetic acid and boiled briefly at reflux. The resulting pigment suspension is filtered at 50 ° C. The filter cake is suspended in 300 ml of methanol and the pigment is filtered again. Finally, it is washed with methanol and water until the colorless filtrate is drained and dried at 80 ° C under vacuum. 9.04 g (62.8 percent of theory, based on dimethyl succinate) of the pure pigment of formula VI are obtained.

which, when incorporated into polyvinyl chloride, gives a red coloration.

Instead of dimethyl succinate, diethyl succinate can be used without particular disadvantages.

Example 2 g of potassium tert-butylate is suspended in 100 ml of dry tert-amyl alcohol and dissolved to a large extent. 20.6 g of benzonitrile is added and the mixture is heated to about 97 ° C. Once this temperature is reached, a solution of 23.0 g of di-tert-butyl succinate and 10 ml of t-amyl alcohol is allowed to flow under stirring for 3 and 1/4 hours using a metering pump. The reaction temperature is maintained at 96-98 ° C and the resulting tert-butyl alcohol is partially distilled off. After the addition was complete, the reaction mixture was maintained at 95-97 ° C for two hours and then worked up as in Example 1 using 13.2 mL of glacial acetic acid instead of 10.8 mL. After drying under vacuum at 80 [deg.] C., 17.6 g of pure pigment of the formula VI are obtained, corresponding to 60.9% of theory, based on the ester used. Unreacted benzonitrile can be recovered from the mother liquor.

Example 3

4.6 g of sodium are first dissolved in 65 ml of sec-butyl alcohol at reflux (about 97 ° C) for about 5 hours). The solution obtained is cooled to about 50 ° C, 51.6 g of benzonitrile is added and the mixture is heated to 97 ° C. Then 23.0 g of di-sec-butyl succinate are allowed to flow in over a period of about three hours using a metering pump and the reaction temperature is maintained at 97 ° C (reflux temperature). After the addition was complete, the mixture was maintained at 97 ° C for one and a half hours and then worked up as described in Example 1, but using 12.6 ml of glacial acetic acid instead of 10.8 ml; dried in vacuo at 80 ° C

8.7 g of pure pigment of formula VI, corresponding to 30.2% of theory, based on the ester used. Examples 4 to 14

23.0 g of potassium tert-butylate are suspended in approximately 95 ml of dry tert-amyl alcohol and dissolve to a large extent with stirring. Then 0.2 mol of nitrile of formula (I) is added

R = CN where

R is as defined in Table I. Heat the mixture to the temperature indicated in the table. Once this reaction temperature has been reached, a solution consisting of 13.25 ml of dimethyl succinate and 5 ml of t-amyl alcohol is allowed to flow over the time indicated in the table using a metering pump. The reaction mixture is stirred gently. The temperature is maintained and the methanol formed is distilled off. If the mixture is too viscous, it may be diluted with a little t-amyl alcohol. After the addition was complete, the reaction temperature was maintained at the same temperature for two hours and then worked up as in Example 1 using 13.2 ml of glacial acetic acid instead of 10.8 ml. After drying under vacuum at 80 degrees Celsius, a pigment of formula (I) is obtained in the yield shown in the table

where

R is as defined in Table I

Example R number

Cl

whose·

CH 2 OOC

-o enga® »;

Table I

Reaction temperature Noc: 2 ° C Time inflow clock Yield ⁺ % Shade in PVC (0.2%) 97 to 99 3 3/4 23.4 red 89 to 91 2 56.8 orange 88 to 91 2 39.5 claret 89 to 91 2 1/4 6.6 red 89 to 91 2 1/4 77.5 red- orange 90 to 91 2 1/2 80.0 claret 89 to 90 1 3/4 43.1 red 89 to 91 1 3/4 67.6 red 87 to 92 2 76.5 red 95 to 97 2 4,5 orange 96 to 97 1 3/4 24.2 red

⁺ yield always based on succinic diester introduced into the reaction

Examples 15 to 37

To 145 ml of tert-amyl alcohol was added 0.12 g of sulfosuccinic acid bis-2-acetylhexyl ester as the sodium salt and 8.3 g of sodium under a nitrogen atmosphere. The mixture was heated to 95-102 ° C with gentle stirring. Once the sodium has melted, the emulsion is stirred vigorously for three to five hours at a temperature of 9-102 ° C. The solution thus obtained is mixed with 0.24 mol of a nitrile of the general formula

R‘ — CN or

R '—CN where

R ‘and R mají have the same meaning as given in Table II (Examples 15 to 25), or with 0.12 mol. nitrile of the general formula

R‘-CN and with 0.12 moles of nitrile of general formula

R '- CN where

R ‘and R mají have different meanings given in Table III (Examples 26 to 37). At the reaction temperature indicated in Table II and Table III, 1.2 mol of diisopropyl succinate dissolved in 12 ml of tert-butyl alcohol are added over the time indicated in Table II and Table II. The resulting isopropanol is continuously distilled off. After the addition was complete, the mixture was maintained at the reaction temperature for two hours and then worked up in a similar manner to Example 1. After drying under vacuum at 80 ° C, the pigment of formula II was obtained in the yields shown in Tables II and III.

where

R ‘and R mají have the meanings indicated in Tables II and III.

Table II

Example R ‘= R“ number

Reaction temperature ° C

Time of inflow hour

Yield *%

Shade in PVC (0.2%)

105 to 110

105 to 110

105 to 110

105 to 110

105 to 110

105 to 110

105 to 110

2.5

2.5

56.8 orange yellow

65,0 red

44.9 red

36,7 red-violet

10,0 claret

55,2 red

52,4 red

Example number R ‘= R ' Reaction temperature Noc: 2 ° C Time inflow clock Yield ⁺ % Shade in PVC (0.2%) 22nd ŮT 90 1 17.9 violet 23 105 to 110 2 41.8 red 24 HIVE and 85 1 42.0 claret

70,4 red

Table III

Example R ‘number

Reaction Time Výě- Shade temperature přité- Item ⁴ · in PVC Noc: 2 ° C repentance clock % (0.2%)

105 to 110 2.5

1.3

105 to 110 2.5

105 to 110 2.5

105 to 110 2.5

105 to 110 2.5

105 to 1101

105 to 110 2.5

104 2.5

66,9 red

64.1 red-violet

52.2 red

49.5 orange

54.6 red

71.4 red

47,8 red

44.5 red

68.3 orange

35 O 105 to 1102.5 56.1 claret 36 h ₃ co-Q- 105 to 110 2.5 46.3 red 37 ^CH rO- ct-Q- 105 to 110 2.5 56.4 claret

^{+ the} yield in Tables II and III is always based on the succinic diester introduced into the reaction

Example 38

4.8 g of sodium and 0.1 g of sodium lauryl sulphate as emulsifier are stirred together in 117 ml of t-amyl alcohol at 94-100 ° C until the sodium is completely dissolved. After cooling, 25.6 g of dry isonitrile dinitrile are added and a solution of 13.25 ml of succinic acid dimethyl ester and 5 ml of tert-amyl alcohol is passed through the metering pump for two hours at 88-92 degrees Celsius. Stir at 88-92 ° C and continuously evolve the methanol formed. After the addition was complete, the reaction mixture was maintained at 90 ° C for two hours and then worked up as described in Example 1 using 13.2 ml of glacial acetic acid instead of 10.8 ml. After drying under vacuum at 80 DEG C., 25.5 g, i.e. 75.5% of theory, based on the succinic acid dimethyl ester of the pigment of formula (VII), are obtained.

(Vil)

The pigment, when incorporated into polyvinyl chloride, dyes polyvinyl chloride to a red-orange color.

Example 1 a d 3 9

If the procedure described in Example 38 is followed but sec-butyl alcohol is used instead of t-amyl alcohol, 20.6 g (60.8% of theory, based on dimethyl succinate) of the pigment of formula VII are obtained.

Example 40

When the procedure described in Example 38 was used as the solvent, tert-amyl alcohol and sodium tert-butoxide as the alcoholate in the sieve were used, yielding 22.9 g (67.8% of theory, based on dimethyl succinate, pigment). of formula VII.

Example 1 a d 4 1

11.5 g of potassium tert-butoxide in 17.4 ml of tert-amyl alcohol and 102.6 ml of benzonitrile are introduced. The mixture was heated to 100 ° C and treated at this temperature with a solution of 11.6 g of di-tert-butyl ester of jan18 tartaric acid in 5 ml of t-amyl alcohol over three hours using a metering pump. The mixture is then held at 100 ° C for two hours and then worked up as described in Example 1, replacing

10.8 ml use 7.2 ml of glacial acetic acid. After drying in vacuo at 80 DEG C., 10.15 g (70.4% of theory) based on di-tert-butyl succinate, pure pigment VI, are obtained.

Example 42

11.5 g of potassium tert-butylate are suspended in 53.2 ml of tert-amyl alcohol and mixed with 36.8 ml of benzonitrile. The mixture was heated to 98 ° C and treated at this temperature with a solution of 13.6 g of diphenyl succinate in 35 ml of benzonitrile over two and three quarters of an hour. The reaction mixture is then held at 100 DEG C. for one and a half hours and finally treated as described in Example 1, but using 6.9 ml of glacial acetic acid instead of 10.8 ml. After drying under vacuum at 80 DEG C., 1.66 g (11.5% of theory, based on succinic acid diphenyl ester) of pigment, m.p. ce VI.

Example 43

11.5 g of potassium tert-butoxide are suspended in 100 ml of toluene and the mixture is heated to 90 ° C. A solution of 6.63 ml of dimethyl succinate and 25.6 ml of benzonitrile is then added over two hours. The reaction mixture was stirred for 16 hours at 90 ° C and then worked up as described in Example 1 using 7.2 ml of glacial acetic acid instead of 10.8 ml. After drying in vacuo at 80 DEG C., 2.54 g (17.6 percent of theory), based on the succinic acid dimethyl ester, of pure pigment VI, is obtained.

Example 44

4.6 g of sodium and 0.1 g of sodium lauryl sulfate in 70 ml of tert-amyl alcohol are introduced. This suspension was heated to reflux (95-100 ° C). 20.7 ml of tert-butyl alcohol are then added dropwise over two hours. The mixture is refluxed (95-100 ° C) until the metal is completely dissolved. After cooling to room temperature, 59.2 g of 4-tolunitrile are added and heated to 97 ° C. A solution of 22.1 g of monoisopropyl mono-tert-butyl succinate in 10.0 ml of tert-amyl alcohol is then metered in over four hours while maintaining the temperature at 97-99 ° C. It is then stirred for one and a half hours at the same temperature and worked up as in Example 1 using 13.2 ml of glacial acetic acid instead of 10.8 ml. After drying under vacuum

23B794 at 80 [deg.] C. yields 15.4 g, i.e. 48.6% of theory, based on the diester of succinic acid, a pigment of formula VIII which, when incorporated into polyvinyl chloride, gives red

Example 45

4.6 g of potassium tert-butylate are suspended in 20 ml of 3-methyl-3-pentanol and mixed with 5.94 g of 4-dimethylaminobenzonitrile. It is heated to 120 DEG C. and a solution of 2.65 ml of dimethyl succinate in 6 ml of 3-methyl-3-pentanol is added dropwise over two hours. It is then held for two hours at 120 DEG C. and worked up as described in Example 1 using 2.3 ml of glacial acetic acid instead of 10.8 ml of glacial acetic acid. It is dried under vacuum at 80 DEG C. to give 0.28 g (3.7% of theory, based on dimethyl succinic acid) of the pigment of formula (IX) which, when incorporated into polyvinyl chloride, gives a blue color.

Example 46

23.0 g of potassium tert-butylate are suspended in 145 ml of anhydrous tert-amyl alcohol and stirred until the potassium tert-butylate is largely dissolved. Then 12.8 g of terephthalonitrile and 12.8 g of isophthalonitrile are added. The mixture is heated to about 90 ° C and then a solution of 13.25 ml of dimethyl succinate in 5 ml of t-amyl alcohol is added over a period of two and a half hours using a metering pump. The temperature is maintained at about 90 ° C and methanol formed is distilled off. After the addition was complete, the reaction mixture was maintained at about 90 ° C for one and a half hours and then worked up as described in Example 1, but using 12.6 ml of glacial acetic acid instead of 10.8 ml. After drying in vacuo at 80 DEG C., 24.5 g (72.5% of theory), based on dimethyl succinate, of the pigment of formula X, is obtained which, when incorporated into polyvinyl chloride, gives a red coloration.

Example 47

3.4 g of the pigment of Example 9 and 2.9 g of the pigment of Example 12 in 100 ml of anhydrous dimethylformamide are mixed with 7.43 ml of a 30% by weight solution of sodium methylate in methanol. After stirring at room temperature for about 15 minutes, a solution of 2.52 ml of glacial acetic acid in 60 ml of methanol was added dropwise over 30 minutes and the suspension was washed for several hours at room temperature. After filtration, washing and drying, 5.4 g of the pigment mixture of Examples 9 and 12 are obtained.

Example 48

To 1440 ml of dry tert-amyl alcohol was added 82.8 g of sodium and 1.2 g of dry succinic acid sodium bis-2-ethylhexyl ester emulsifier under a nitrogen atmosphere. The mixture is heated to a temperature of about 100 ° C and maintained at reflux until the metal is completely dissolved. The solution obtained is cooled to approximately 80 ° C and mixed with 247.2 g of dry benzonitrile. The mixture is then heated to about 110 ° C and 242.4 g of dry succinic acid diisopropyl ester are added over about six hours. At the same time, the isopropanol formed is distilled off. After the addition was complete, it was left to react for two hours, then the mixture was cooled to about 60 ° C and diluted with 1650 mL of methanol. Fak was slowly added to a mixture containing 227 ml of glacial acetic acid and 150 ml of methanol to precipitate the pigment. The product is then filtered off at approximately 60 ° C and washed successively with 3000 ml of methanol and 2000 ml of hot water. After drying under vacuum at 70 [deg.] C., 228.3 g (66% of theory, based on benzonitrile) of the pigment of formula (VI) are obtained.

Example 1 4 9

The procedure is as described in Example 48 except that dineopentyl succinate is also used instead of diisopropyl succinate b) di-2-butyl succinate or dicyclohexyl succinate; or

d) di-tert-butyl ester of succinic acid yields a pigment of the formula VI in the following percentages, in each case based on benzonitrile with ester and 64.9% with ester bj 65.2% with ester cj 71.5% with ester dj 75, 7%.

Example 50

Following the procedure described in Example 48, the amount of diisopropyl succinate and sodium diisopropyl succinate used was increased by 30% by weight to give the pigment of formula VI in 81.9% of theory based on benzonitrile.

Example 51

6.9 g of sodium are introduced under argon in 100 ml of toluene and 26.5 g of 2-methyl-2-butanol. The mixture was stirred at reflux (approximately 100 ° C) until the metal was completely dissolved. At 70 DEG-80 DEG C., a mixture of 21 ml of benzonitrile, 23 g of di-tert-butyl succinate and 20 ml of toluene is added dropwise over 4 to 5 hours. The suspension is stirred for approximately 19 hours at 80-90 ° C, then neutralized at 60 ° C by dropwise addition of a mixture of 21 ml of glacial acetic acid and 80 ml of methanol over approximately one and a half hours and stirred for an additional 30 minutes. The pigment suspension is filtered at 60 ° C, washed first with methanol and then with water until the colorless filtrate is drained. After drying in a vacuum oven at 80 [deg.] C., 23.8 g of pure pigment, i.e. approximately 82.5% of the theory based on di-tert-butyl succinate, according to Example 1 of formula VI, are obtained.

Example 52

3.4 g of a 45% by weight dispersion of sodium in paraffin in 30 ml of toluene are introduced under an argon atmosphere. A mixture of 14 ml of benzonitrile, 7.6 g of di-tert-butyl succinate and 27 ml of toluene is added dropwise over approximately two hours. The temperature is gradually increased from 20 to 70 ° C. Stirring is continued for approximately 20 hours at 80 DEG C., whereupon the pigment precipitates. After neutralization with a mixture of 3.6 ml of glacial acetic acid and 27 ml of methanol, the suspension is filtered, washed with acetone and then with water until the colorless filtrate is drained. After drying in a vacuum oven at 80 [deg.] C., 5.6 g of a pigment, i.e. about 58.9% of theory based on di-tert-butyl succinate, are obtained, the pigment having the formula VI.

Example 53

If the procedure described in Example 48 was followed but finally neutralized by weight with 8% hydrochloric acid instead of a mixture of glacial acetic acid and methanol, 230 g of pure pigment of formula VI, i.e. 66.5% of theory based on diisopropyl acid, were obtained. amber.

Example 54

41.4 g of sodium are added in portions, followed by 0.6 g of sulfosuccinic acid bis-2-ethylhexyl ester as the sodium salt emulsifier under nitrogen in 720 ml of tert-amyl alcohol. The mixture was heated to 95-102 ° C with slow stirring, then stirred under reflux for 4-6 hours at 95 ° C or higher, with complete stirring, until the metal was completely dissolved. 170 g of 4-chlorobenzonitrile are then added to the solution at 80 DEG-85 DEG C. The mixture is then heated to 110 DEG. To these mixtures is then added over a period of three hours with gentle stirring and nitrogen introduction

121.5 g of diisopropyl succinate. The mixture was then stirred for 90 minutes, cooled to 50 ° C and then added to 1400 ml of water at 95-100 ° C over 30 minutes with good stirring. The biphasic mixture thus obtained is stirred under reflux for 20 hours. 550 ml of a mixture of tert-amyl alcohol and water are distilled off under stirring with nitrogen introduction over a period of 3 to 4 hours, the thus obtained pigment suspension at 90 DEG C. is filtered off, the pressed cake is washed with hot water until neutral and dried. vacuum oven at 80 ° C. 148 g of a frequent pigment are obtained (yield = 68% of theory, based on succinic acid diisopropyl ester), the formula of which is as in Example 6, Table I.

Example 55

To 470 g of dry tert-amyl alcohol, 34.5 g of sodium are added with stirring and nitrogen introduction, followed by 0.5 g of dry sulfosuccinic acid bis-2-ethylhexyl ester emulsifier. The mixture was then heated to 100 ° C with slow stirring. The metal melts. The mixture is then maintained under reflux with vigorous stirring until the metal has completely dissolved. The solution obtained is cooled to approximately 80 ° C and mixed with 103 g of dry benzonitrile. The mixture is then heated to a temperature of about 110 DEG C. and 101 g of dry succinic acid diisopropyl ester are metered in over about three hours. At the same time, the isopropanol formed is distilled off. After the addition was complete, it was left to react for two hours, the mixture was cooled to room temperature and diluted with 195 ml of isopropanol. The suspension is then poured into 570 g of water at room temperature with good stirring, forming a two-phase system. It is then allowed to react for one hour with vigorous stirring, the product is filtered off and the aspirated pigment cake is washed first with hot water and then with cold isopropanol. After drying under vacuum at 80 DEG C., 87 g (approximately 61% of theory, based on the di-isopropyl succinate introduced) of the pigment of the formula VI are obtained.

Claims (10)

SUBJECT A process for the preparation of 1,4-diketopyrrolo [3,4-c] pyrrole of the general formula I wherein: R1 and R2 independently of one another a phenyl, naphthyl, diphenyl, pyridyl, furanyl or thiophenyl group which are optionally substituted with substituents not causing water solubility, characterized in that 1 mol of symmetrical or asymmetric dialkyl succinate of 1 to 18 carbon atoms is reacted in an alkyl moiety, a diaryl ester of 6 to 10 carbon atoms in an aryl moiety optionally substituted by a halogen atom or a C1-C6 alkyl or C1-C6 alkoxy or a dicyclohexyl succinate with two moles of the nitrile of formula II or III R1 - CN (Π) or R 2 -CN (III) wherein R1 and R2 are as defined above, or with 1 mole of a nitrile of formula II and 1 mole of a nitrile of formula III in an organic solvent in the presence of an alkali alcoholate having 1 to 10 carbon atoms or alkali metal as a strong base at 60 to 140 ° C; by reaction the product is hydrolyzed. 2. The method of claim 1, wherein: In the present invention, a single nitrile of formula II or formula III is used as starting material. 3. A process according to claim 1, wherein the starting materials are a nitrile of formula (II) and / or of formula (III) in which R1 and R2 are phenyl or naphthyl, optionally substituted by non-water-soluble groups. 4. A process according to claim 1, wherein the starting material is a nitrile of the formula IV Rfj (IV) where they mean R9, R10 and R11 independently of one another are hydrogen, fluorine, chlorine or bromine, carbamoyl, cyano, trifluoromethyl, alkylcarbamoyl of 2 to 13 carbon atoms, alkyl of 1 to 12 carbon atoms, alkoxy of 1 to 12 atoms C 1 -C 12 alkylmercapto, C 2 -C 13 alkoxycarbonyl, C 2 -C 13 alkanoylamino, C 1 -C 12 monoalkylamino, C 2 -C 24 dialkylamino, optionally halogen, alkyl C 1 -C 12 or C 1 -C 12 alkoxy substituted phenoxy, phenylmercapto, phenoxycarbonyl, phenylcarbamoyl or benzoylamino, wherein at least one of R 9, R 10 and R 11 is hydrogen. 5. Process according to claim 1, characterized in that a nitrile of the general formula V (V) is used as the starting material: R 8 and R 13 are a chlorine or bromine atom, a C 1 -C 4 alkyl group, a cyano group, a C 1 -C 4 alkoxy group, or a chlorine atom substituted by a phenoxy group, a carbamoyl group, a C 2 -C 5 alkylcarbnoyl group a phenyl, carbamoyl, methyl or methoxy group, and a second hydrogen atom. 6. A process according to claim 1, wherein the diester of succinic acid is a symmetrical dialkyl succinate of 1 to 18 carbon atoms in each alkyl moiety. 7. A process according to claim 1, wherein the diester of succinic acid is a symmetrical dialkyl succinate wherein the alkyl moiety of from 1 to 18 carbon atoms is a secondary or tertiary alkyl group of from 1 to 16 carbon atoms. 8. A process according to claim 1, wherein the solvent is a secondary or tertiary alcohol. 9. A process according to claim 1, wherein the strong base is an alkali alcoholate having from 1 to 10 carbon atoms as the strong base. 10. Process according to claim 1, characterized in that an organic acid is used for the hydrolysis.