HU190489B - Process for preparing pyrrolo/3,4-c/pyrroles - Google Patents

Abstract

The process is 1,4-diketopyrrolo [3,4-] pyrrole of formula (I) which are wherein R 1 and R 2 are independently of one another unsubstituted or mono or halogen disubstituted C 1-4 alkyl mono- or disubstituted, C 1-4 alkoxy, (C 1 -C 4) alkoxycarbonyl, cyano, trifluoromethyl, di (1-4C) alkyl, C 1-4 alkylthio, phenylthio, phenoxy, phenyl or a phenyl group monosubstituted with cyanophenyl, naphthyl, furyl or thienyl; unsubstituted or C 1-8 alkoxy substituted pyridyl. The procedure is performed in such a way that 1 mole is asymmetric or symmetric succinic acid (1-8 alkyl) - ester, succinic diphenyl ester or succinic acid dicyclohexyl ester organic solvent in alkali metal, alkali metal alcohols or alkali metals in the presence of a strong base, at a temperature of 60-140 ° C, if Rt and R2 have the same meaning, (II) or (III) with 2 moles of nitrile of formula II or when R 2 and R 2 having different meanings, 1 mol of Formula II and 1 mole is reacted with nitrile of formula III the resulting reaction product is of formula (I) the compound is liberated by acid hydrolysis.

Description

The present invention relates to a process for the preparation of 1,4-diketopyrrolo [3,4-c] pyrroles which represent highly valuable pigments. However, for the preparation of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole from benzonitrile and ethyl bromoacetate in the presence of activated zinc copper, Tetrahedron Lett. 1974, 2549-2552. A process is described in the literature, but the yield so far has proved to be insufficient. Conversely, when starting from a succinic ester and an aromatic nitrile, the desired pyrrolo [3,4-c] pyrrole pigments are obtained in substantially higher yields under defined reaction conditions. Furthermore, according to the invention may be prepared by a novel pyrrolo [3,4-c] pyrroles, ^he which are not or only with great difficulty can be prepared by the previously known method.

Thus, the present invention relates to a process for the preparation of 1,4-diketopyrrolo [3,4-c] pyrroles of formula I wherein R 1 and R ₂ are independently unsubstituted or mono- or disubstituted with halogen atoms. mono- or disubstituted with C 1 -C 4 alkyl,

C1-4 alkoxy, (C1-4) alkoxycarbonyl, cyano, trifluoromethyl, di (4 szénato- ²⁵ mos alkilj amino, C 1-4 alkylthio, phenylthio, , phenoxy, phenyl or cyanophenyl monosubstituted phenyl, naphthyl, furyl or thienyl, unsubstituted or substituted pyridyl C1-8 alkoxy means ^30, where the meaning of the invention, by reacting 1 mol of a symmetric or asymmetric bo 'Ostyánkősav-di (Cl-C8) ester, succinic acid diphenyl ester or borostyánkősavdiciklohexil ester organic solvent, ^sub-35 alkali metal alcoholates or alkali as a strong base in the presence of 60 to 140 ° C temperature, when R and R ₂ are reacted with 2 moles of the same nitrile of formula (II) or (III) or, when R 1 and R _{2 are} different, 1 mol of the formula (II) and 1 mole (III) of ⁴⁰ nitrile and from the action product, the compound of formula I is liberated by acid hydrolysis.

The groups R ₁ and R ₂ are different or the same and may be preferably the same. The phenyl groups R ₁ and R ₂ 45 may have water-insoluble substituents such as:

1. halogen atoms such as chlorine, bromine or fluorine;

2. C 1 -C 4 straight or branched hydrocarbon alkyl groups;

Examples of alkyl groups include methyl, ethyl, n-propylisopropyl, η-butyl, sec-butyl and tert-butyl;

3. C 1 -C 4 alkoxy such as methoxy, ethoxy, n-propoxy or isopropoxy;

4. C 1-4 alkylthio such as methyl, ethyl, n-propyl and isopropylthio;

5) cyano;

6. -NR ₄ R ₅ wherein R ₄ and R 1 are C 1-4 alkyl such as dimethylamino and diethylamino; i

C7 -C5 alkoxycarbonyl groups such as methoxy, ethoxy, isopropoxy, tert-butoxy and n-butoxycarbonyl.

For the preparation of the compounds of the formula I according to the invention, it is preferable to use a uniform nitrile of the formula II or III as starting material. Also preferred are nitriles of formula (II) and / or (III) wherein R ₁ and R ₂ represent a phenyl or naphthyl group containing unsubstituted or water-insoluble substituents.

Suitable di-esters of succinic acids include dialkyl or diphenyl esters. In the case of succinic acid dialkyl ester, the alkyl group may be straight or branched, preferably branched, and may contain from 1 to 8, preferably from 1 to 5, carbon atoms. As the branched alkyl group, the sequester or tertiary alkyl group such as isopropyl, sec-butyl, tert-butyl, tert-amyl and cyclohexyl are preferred.

Examples of succinic acid diester include succinic acid 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- [1,1-dimethylbutyl] ester, -dif. , 3,3-tetramethylbutyl] ester, di- [1,1-dimethylpentyl ester, di- [1-methyl-1-ethylbutyl] ester, -di [1,1-diethylpropyl] ester, diphenyl ester and dicyclohexyl ester.

The nitriles of formula (II) and (III) and succinic acid diesters may be prepared according to known methods and procedures.

The succinic acid diester is reacted with the nitrile in an organic solvent medium. Suitable solvents are, for example, C 1 -C 10 primary, secondary or tertiary alcohols such as methanol, ethanol, m-propanol, isopropanol, n-butanol, sec-butaryol, t-butanol, n-pentanol, 2-methyl-2-butanol, -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 ethers such as tetrahydrofuran or dioxane or glycol ethers such as ethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol monomethyl ether or diethylene glycol monoethyl ether, and bipolar aprotic solvents such as acetonitrile, benzonitrile, dimethylformamide, Ν, Ν-dimethylacetamide, nitrobenzene, N-methylpyrrolidone, aliphatic or aromatic hydrocarbons such as benzene or benzene substituted with alkyl or alkoxy or halogen such as toluene, xylene, anisole or chlorobenzene or aromatic N-heterocyclic compounds such as pyridine, picoline or quinoline. In addition, it is also possible that the nitrile of formula (II) or (III) to be reacted is also used as a solvent provided that it is in the liquid state within the reaction temperature range. The solvents mentioned may also be used as mixtures. Preferably, it is based on 1 unit by weight of the compounds involved in the reaction

5 to 20 parts by weight of solvent are used.

Preferably, the solvent used in the process of the invention is an alcohol, especially a secondary or tertiary alcohol. Preferred tertiary alcohols a

190,489 tert-butanol and tert-amyl alcohol. In addition, mixtures of these preferred solvents with aromatic hydrocarbons such as toluene or xylene or a halogen substituted benzene such as chlorobenzene are also very suitable. ⁵

According to the invention, the reaction is carried out in the presence of a strong base. Suitable strong bases are in particular the alkali metals themselves, such as lithium, sodium or potassium or alkali metal amides such as lithium, sodium or potassium amides or alkali metal hydrides such as lithium, sodium or potassium hydride or alkaline earth or alkali metal alcoholates, in particular those derived from 1-10 carbon atoms, primary, secondary or tertiary alcohols, ¹⁵ such as the lithium, sodium or potassium 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-3-pentylate. The named bases may also be used in admixture.

The strong base is preferably an alkali metal alkoxide in the present invention, in which the alkali metal is sodium or potassium and particularly where the alkoxide is derived from a secondary or tertiary alcohol ^25. For example, particularly preferred strong bases are sodium or potassium isopropylate, sec-butylate, tert-butylate and tert-butylate. Additionally, the alkali metal alcoholates may be prepared in situ by reacting the corresponding alcohol with the alkali metal, alkali metal hydride or alkali metal amide.

Particularly 0.1 to 10 mol, preferably 1.9 to 4.0 mol, of a strong base are used in the process according to the invention, in particular 0.1 to 10 mol, preferably 1.9 to 4.0 mol. Although basically a stoichiometric amount of the base is sufficient, the excess of base will in many cases have a positive effect on the yield. According to the invention, the reaction is carried out in particular at 60-140 ° C, preferably at 80-120 ° C.

The hydrolysis of the condensation product may be carried out with water, a C 1 -C 4 alcohol such as methanol or ethanol, but preferably with an acid. Among the acids, for example, aliphatic or aromatic carbonic or sulfonic acids such as formic acid, acetic acid, propionic acid, oxalic acid, benzoic acid or benzenesulfonic acid can be used. Other acids which may be used are mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid. Organic acids, especially aliphatic carboxylic acids such as acetic acid, are preferably used for hydrolysis.

During hydrolysis, the compound of formula (1) precipitates and can be isolated by filtration.

The reaction of the succinic acid diester with nitriles of general formulas (II) to (IV) may be carried out essentially by mixing all components at a lower temperature and then heating the mixture to the reaction temperature, but also by reacting each of the components temperature range is added to each other in any order. In one preferred procedure, which usually leads to particularly good yields, the nitrile to be reacted with the base in preparing the succinic acid diester added to θ ₅ of the reaction temperature range. Alternatively, the succinic acid diester and the nitrile to be reacted are added simultaneously to the prepared base. The process according to the invention can be carried out not only in batch mode but also in continuous mode.

In particular, succinic diesters containing lower alkyl groups and alcoholates derived from lower alcohols such as methanol, ethanol, n-propanol, isopropanol or tert-butanol may require that the lower alcohol produced during the reaction .

When alcohol is used as solvent and alcoholate as base is used, it may be advantageous to use alcohol and alcoholate having the same alkyl groups. It may also be advantageous if the succinic acid diester additionally contains the same alkyl groups.

In another preferred embodiment of the process, the nitrile to be reacted is used in an amount greater than the stoichiometric. It has been found that by using an excess of nitrile relative to succinic diester, when the optimum amount is determined according to the particular reaction partners, and the stoichiometric amount of succinic acid diester can be further increased, the yield may be improved. The excess nitrile is usually recoverable. In many cases, an excess of succinic acid diester relative to nitrile, which may be twice the stoichiometric amount of succinic acid diester, may have a positive effect on yield.

When R ₁ and R ₂ are aromatic N-heterocyclic groups, the compounds of formula (I) according to the invention are novel. R 1 and R _{2 are,} for example, O, m or p-pyridyl.

Depending on the type of substituents and the polymers to be colored, the compounds of formula I may also be used as polymer soluble dyes. However, the compounds of formula (I) are usually used as pigments of high molecular weight organic materials. In general, the pigments can be used directly in the form as obtained by the process of the invention.

Depending on the intended use, the pigments obtained by the process of the invention may be converted to a higher opacity or a more transparent version.

If the transparent version is to be targeted, it is advantageous to carry out the hydrolysis at lower temperatures (below 80 ° C).

If a higher opacity pigment form is desired, then hydrolysis at higher temperatures (above 80 'C) and possibly under pressure may be desirable. To obtain an opacifying variable, the pigment isolated after hydrolysis may be subsequently heated in water or in an organic solvent, possibly under pressure.

190,489

Preferred are organic solvents which boil above 80 ° C. They are particularly suitable for the halogen atoms, alkyl or nitro groups, substituted benzenes, such as xylenes, chlorobenzene, ^o-dichloro-5 benzene or nitrobenzene, and pyridine bases such as pyridine, picoline or quinoline, and ketones, such as cyclohexanone, ethers, such as ethylene glycol monomethyl or monoethyl ether, amides, such as ¹⁰ dimethyl formamide or N-methylpyrrolidone as well as dimethyl sulfoxide or sulfolane. The curing can also be carried out in water, in the presence of organic solvents and / or with the addition of surfactants. ¹⁵

Depending on the purpose of use, it may be advantageous to prepare mixtures of compounds of formula (I). This may be achieved for example by in that the different reaction solutions were mixed each independently prepared before hydrolysis, hydrolyze ²⁰ then, purified and isolated. It is also possible to co-precipitate two or more compounds of formula (I).

High molecular weight organic substances which can be colored or pigmented with the compounds of formula (I) include, for example, cellulose ethers or esters such as ethyl cellulose, nitrocellulose, cellulose acetate, cellulose butylate, natural and synthetic resins such as the polymerization resins or condensation resins, for example aminoplasts, KU ³⁰ lönösen urea and melamine-formaldehyde resins, alkyd resins, Phenoplast, polycarbonates, polyolefins such as polystyrene, polyvinyl chloride, polyethylene, polypropylene, polyacrylonitrile, poliakrilsavészter, polyamides, polyurethanes, and polyesters, rubber, casein, silicone and silicone resins, or mixtures thereof.

In addition, it does not matter whether the said high molecular weight organic compounds are available in the form of a plastic paste, melt, spinning solution, lacquer, lacquer or printing ink. Depending on the purpose of use, it will be advantageous to use the pigments of the present invention as colorants or preparations. Compounds of formula I are preferably present in an amount of 0.1 to 10% by weight, based on the 45 high molecular weight organic substances to be pigmented.

For example, the colors available in plastics, fibers, varnishes or prints are distinguished by their high color intensity, good dispersion and varnishability, good migration, heat, light and weather resistance, and beautiful light.

The invention is illustrated by the following examples.

Example 1

A mixture of 48.2 ml of tertiary amyl alcohol, 17.3 g of potassium tert-butylate and 72.2 g of benzonitrile, preferably anhydrous, is heated to about 98 ° C under a nitrogen atmosphere. When this temperature was reached, a metering pump was added 7.31 g succinic acid dimethyl ester in 5.0 ml of serum possibility _g5 Rint anhydrous solution of tert-amyl alcohol is prepared, over a period of 145 minutes. The temperature is kept constant at 98-99 ° C. The methanol formed is distilled off. After the addition was complete, the reaction mixture was heated at 99 ° C for 2 hours and then cooled to 65 ° C. It is then slowly diluted with 100 ml of methanol, slowly neutralized with 10.8 ml of glacial acetic acid and refluxed briefly. The resulting pigment slurry was filtered at 50 ° C, then the pigment was slurried in 300 ml of methanol and filtered again, finally washed with methanol and water until they were colorless and dried in vacuo at 80 ° C. 9.04 g (theoretical value for dimethyl succinic acid)

62.8%) gives a pure pigment of formula VI which when incorporated into polyvinyl chloride gives a red level.

Instead of succinic acid dimethyl ester, succinic acid diethyl ester can be used without particular disadvantages.

Example 2

It is suspended in 100 ml of dry tertiary amyl alcohol and then 23 g of potassium tert-butylate are dissolved. 20.6 g of benzonitrile are added and the mixture is heated to about 97 ° C. Once this temperature has been reached, a solution of 23.0 g of succinic acid di-tert-butyl ester in 10 ml of tert-amyl alcohol is added under stirring over a 3 '/ 4 hour period with a metering pump. The reaction temperature was maintained at 96-98 ° C and the resulting tert-butyl alcohols were partially distilled off. After the addition was complete, the reaction mixture was heated at 95-97 ° C for 2 hours and then worked up as described in Example 1, except that 13.2 ml of glacial acetic acid was used instead of 10.8 ml. After drying under vacuum at 80 'C, 17.6 g of the pure pigment of formula VI are obtained, which corresponds to 60.9% of the theoretical value with respect to the ester used. The unreacted benzonitrile can be recovered from the mother liquor.

Example 3 Under reflux (about 97 ° C), ml of sec-butyl alcohol was first dissolved

4.6 g of sodium (about 5 hours). The resulting solution was cooled to about 50 ° C and added

51.6 g of benzonitrile are added and the mixture is heated to 97 'C. Subsequently, 23.0 g of succinic acid di-butyl ester were added via a metering pump over a period of 3 hours and the reaction temperature was kept constant at 97 ° C (reflux temperature). After the addition was complete, the reaction mixture was heated at 97 ° C for 1 V 2 hours and worked up as described in Example 1 (using 12.6 ml glacial acetic acid instead of 10.8 ml). After drying under vacuum at 80 'C, 8.7 g of pure pigment of formula VI are obtained, corresponding to 30.2% of the theoretical value with respect to the ester used.

190,489

4-14. example

Potassium tert-butylate (23.0 g) was suspended in dry tertiary amyl alcohol (about 95 ml) and dissolved with stirring. Then, 0.2 to ⁵ moles of nitrile of the formula R-CN are added, wherein R is as defined in Table I. The mixture was heated to the temperature shown in Table I. As the reaction temperature has been reached, a dosing pump over ¹⁰ in Table I given time, with gentle stirring, add 5 ml of tert-amyl alcohol solution of succinic acid dimethyl ester, 13.25 ml. The mixture was kept at the indicated temperature and the methanol formed was distilled off. If the mixture becomes too thick, it can be diluted with some tertiary amyl alcohol. After the addition was complete, the reaction mixture is kept at the same temperature for 2 hours as in Example 1. SHALL _v worked up accordingly with the exception that 13.2 ml of glacial acetic acid was used instead of 10.8 ml ·. After drying in vacuo at 80 ° C-οη, the yield of the pigment (XI) is given in Table I, where R is the group given in Table I.

Table I

Yield (%)

Reaction- ( ^the b y ^{fiber is} yang- Tint

Example p hAmereéw t Addition time for acid diester 0.2%, »p. ^e (hour) relative concentration '' in theory for PVC)

4th 4-methylphenyl 97-99 3% 23.4 red 5th 3-chlorophenyl 89-91 2 56.8 orange 6th 4-chlorophenyl 88-91 2 39.5 claret 7th 4- (methoxycarbonyl) phenyl 89-91 2¼ 6.6 red 8th 3-cyanophenyl 89-91 2 * / 4 77.5 orange 9th 4-cyanophenyl 90-91 2 '/ ₂ 80.0 claret 10th 2-pyridyl 89-90 1% 43.1 red 11th 3-pyridyl 89-91 1% 67.6 red 12th 4-pyridyl 87-92 2 76.5 red 13th 1-naphthyl 95-97 2 4.5 orange 14th 2-naphthyl 96-97 1% 24.2 red

15-37. example

145 ml of tert-amyl alcohol were added 8.3 g of sodium sulfonate and 0.12 g of ₄₀ fo-succinic acid-bis-acetyl-2-ethylhexyl ester sodium salt under nitrogen. The mixture was heated to 95-102 ° C with gentle stirring. Once the sodium has melted, the emulsion is stirred vigorously at 95-102 ° C for 3-5 hours. To the solution thus obtained is added, on the one hand, 0.24 moles of nitrile of the formula R'-CN or R-CN, in which R 'and R are the same and in accordance with the formula II. or on the other hand 0.12 moles of nitrile of the formula R'-CN and 0.12 moles of the nitrile of the formula R-CN, wherein R 'and R are different from those shown in Table III. (Table 26-37). II and III respectively. After reaching the reaction temperature in Table II. and III. 1.2 mole of succinic diisopropyl ester dissolved in 12 ml of tercamyl alcohol was added via a metering pump over the time indicated in Table II. The resulting isopropanol is continuously distilled off. After the addition was complete, the reaction mixture was kept at the same temperature for another 2 hours and then worked up as described in Example 1. After drying in vacuo at 80 'C-οη. and III. Yield Table II gives the pigment of formula (XII) wherein R 'and R' are as defined in Tables II and III respectively. represents the groups specified in Table.

II. spreadsheet

Example number

R '= R

Reaction temperature ('C)

Yield (%) (Amber addition to theoretical value for acid diester (hour))

hue

0.2% concentration

In PVC

15th 3- (trifluoromethyl) phenyl 105-110 3 56.8 orange 16th 4- (pentyloxy) pyridin-3-yl 105-110 3 65.0 red 17th 4- (trifluoromethyl) phenyl 105-110 2.5 44.9 red 18th 4'-cyano-diphenyl-4-yl 105-110 3 36.7 reddish violet 19th difenilil- . 105-110 2.5 10.0 claret

-5190 489

II. Table (continued)

Example number R '= R' Reaction- temperature (° C) Delivery time (hours) Yield (%) (theoretical for succinic acid diester) value) hue 0.2% concentration in case of In PVC 20th 4-tert-butyl-phenyl 105-110 2 55.2 red 21st 3,4-dimethylphenyl 105-110 2 52.4 red 22nd 2-furyl 90 1 17.9 violet 23rd 4-methylphenyl 105-110 2 41.8 red 24th 3-thienyl 85 1 42.0 claret 25th 3,5-dichlorophenyl 85 1 70.4 red

III. spreadsheet

Example number R R Reaction- temperatures being (° C) Beadago- riding time (Hours) Yield (%) (theoretical for succinic acid diester) value) Hue at a concentration of 0.2% in PVC 26th phenyl 4-chlorophenyl 105-110 2.5 66.9 red 27th phenyl 4-cyanophenyl 90 L3 64.1 reddish violet 28th phenyl 4-pyridyl 105-110 2.5 52.2 red 29th phenyl 3-pyridyl 105-110 2.5 49.5 orange 30th phenyl 4-methylphenyl 105-110 2.5 54.6 red 31st 4-chlorophenyl 4-pyridyl 105-110 2.5 71.4 red 32nd phenyl 4-methoxyphenyl 105-110 1 47.8 red 33rd 4-chlorophenyl 3-pyridyl 105-110 2.5 44.5 red 34th 4-chlorophenyl 3-chlorophenyl 104 2.5 68.3 orange 35th 4-chlorophenyl 4-methoxyphenyl 105-110 2.5 56.1 claret 36th 4-methylphenyl 4-methoxyphenyl 105-110 2.5 46.3 red 37th 4-methylphenyl 4-chlorophenyl 105-110 2.5 56.4 claret

Physical constants of the new compounds of Examples 10-12, 28, 29, 31 and 33 above (extinction coefficients 40 for the compounds of Examples 10-12, with N-methylpyrrolidone; (Examples 31 and 33 were determined in dimethylformamide solution): ₄₅

Example ε value number 10th 478 14,800 512 20100 11th 473 9,000 507 11,500 12th 480 12,500 515 16,000 28th 471 17,500 504 23,000 29th 470 21,800 503 28,000 31st 479 18400 511 24000 33rd 476 21,600 510 27,200

Example 38

4.6 g of sodium and 0.1 g of sodium lauryl sulfate emulsifier in 117 ml of tertiary amyl alcohol at 94-100 ° C are stirred vigorously until the sodium is completely dissolved. After cooling, 25.6 g of dry isophthalic acid dinitrile are added, and 13.25 ml of succinic acid dimethyl ester, dissolved in 5 ml of tert-amyl alcohol, are added over a period of 2 hours at 88-92 ° C. While stirring, the temperature is maintained at 88-92 ° C and the methanol formed is continuously distilled off. After the addition was complete, the reaction mixture was kept at 90 ° C for 2 hours and then worked up as described in Example 1, except that 13.2 ml glacial acetic acid was used instead of 10.8 ml. After drying under vacuum at 80 DEG C., 25.5 g (75.5% of the theoretical value of succinic acid dimethyl ester) of the formula (VII) is obtained, which when incorporated into polyvinyl chloride gives an orange-red level.

Example 39

The procedure is as in Example 38, but with sec-butyl-61 instead of tert-amyl alcohol.

190,489 alcohol were used. 20.6 g (60.8% of the theoretical value of the ester) of the pigment (VII) are obtained.

Example 40

In the same manner as in Example 38, the solvent used was tertiary amyl alcohol and the sodium alcohol tert-butylate prepared in situ, yielding 22.9 g (67.8% of the theoretical value of the ester) of the formula (VII). pigment.

Example 41

To 11.5 g of potassium tert-butylate are added 17.4 ml of tert-amyl alcohol and 102.6 g of benzonitrile. After heating to 100 ° C, 11.6 g of succinic acid di-tert-butyl ester in 5 ml of tert-amyl alcohol are added over a period of 3 hours via a metering pump. After a further 2 hours at 100 ° C, the reaction mixture was worked up as described in Example 1, except that 7.21 ml glacial acetic acid was used instead of 10.8 ml. After drying under vacuum at 80 'C, 10.15 g (70.4% of the theoretical value of the ester) of the pure pigment (VI) is obtained.

Example 42

11.5 g of potassium tert-butylate are suspended in 53.2 ml of tertiary amyl alcohol and added

36.8 mL of benzonitrile. The mixture is heated to 98 'C and 13.6 g of succinic diphenyl ester in 35 ml of benzonitrile are added over 2 ¾ hours at this temperature. After a further 1½ hours at 100 ° C, the reaction mixture was worked up as described in Example 1 except that 6.9 ml glacial acetic acid was used instead of 10.8 ml. After drying under vacuum at 80 'C, 1.66 g (11.5% of the theoretical value of the ester) of the pigment (VI) is obtained.

Example 43

11.5 g of potassium tert-butylate in 100 ml of toluene are suspended and the mixture is heated to 90 ° C. It is then added over 2 hours

6.63 ml of succinic acid dimethyl ester dissolved in 25.6 ml of benzonitrile. The reaction mixture was stirred for an additional 16 hours at 90 ° C and worked up as described in Example 1 except that

7.2 ml of glacial acetic acid were used instead of 10.8 ml. After drying under vacuum at 80 'C, 2.54 g (17.6% of the theoretical value of the ester) of the pure pigment (VI) are obtained.

Example 44 4.6 g of sodium and 0.1 g of sodium lauryl sulphate are added to ml of tertiary amyl alcohol and the suspension is brought to reflux (95-100 ° C). 20.7 ml of tert-butyl alcohol are then added dropwise over 2 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 the mixture is heated to 97 ° C. Thereafter, 22.1 g of succinic mono-isopropyl mono-tert-butyl ester in 10.0 ml of tert-amyl alcohol are added over a period of about 4 hours while maintaining the temperature at 97-99 ° C, and then for 1 hour. is stirred at the same temperature and finally processed as described in Example 1 except that instead of 10.8 ml

Glacial acetic acid (13.2 ml) was used. After drying under vacuum at 80 'Con, 15.4 g (48.6% of the theoretical value of the ester) of the pigment (VIII) is obtained, which when incorporated into polyvinyl chloride gives a red color.

Example 45 Potassium tert-butylate (4.6 g) in 3-methyl-3-pentanol (ml) was suspended and 4- (dimethylamino) -benzonitrile (5.94 g) was added. The mixture was heated to 120 'Cral and 2.65 ml of succinic acid dimethyl ester dissolved in 6 ml of 3-methyl-3-pentanol was added dropwise over 2 hours. After two hours at 120 ° C, it was worked up as described in Example 1, except that 2.3 ml of glacial acetic acid was used instead of 10.8 ml. After drying under vacuum at 80 'C, 0.28 g (3.7% of the theoretical value of the ester) of the pigment (IX) is obtained, 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 tertiary amyl alcohol, dissolved under stirring, and 12.8 g of terephthalonitrile and 12.8 g of isophthalonitrile are then added. The mixture is heated to about 90 ° C and 13.25 ml of succinic acid dimethyl ester, dissolved in 5 ml of tert-amyl alcohol, are added via a metering pump over 2 hours. The temperature is maintained at about 90 ° C and the methanol formed is distilled off. After the addition, the reaction mixture is maintained at about 90 DEG C. 1 ^l hour and then worked up as described in Example 1, except that 12.6 ml of glacial acetic acid was used instead of 10.8 ml. After drying under vacuum at 80 ° C, 24.5 g (72.5% of the theoretical value of the ester) of the pigment (X) are obtained, which when incorporated into polyvinyl chloride gives a red color.

Example 47

To the pigment of Example 9 (3.4 g) and to the pigment of Example 12 (2.9 g) were added 100 ml of anhydrous dimethylformamide and 7.43 ml of a 30% solution of sodium methylate in methanol. After stirring at room temperature for about 1 hour, 2.52 ml of glacial acetic acid in 60 ml of methanol are added dropwise over 30 minutes and the suspension is stirred for several minutes.

-7190 continue stirring for 489 hours at room temperature. After filtration, washing and drying, 5.4 g of the mixture of pigments of Examples 9 and 12 are obtained.

Example 48

To 1440 ml of dry tertiary amyl alcohol was added 82.8 g of sodium and 1.2 g of bis-2-ethylhexyl ester sodium salt emulsifier under nitrogen. The mixture is heated to about 100 ° C and refluxed until the metal is completely dissolved. The resulting solution was cooled to about 80 ° C and 247.2 g of dry benzonitrile were added. The mixture was then heated to about 110 ° C and 242.4 g of dry succinic diisopropyl ester was added over 6 hours. The resulting isopropanol is simultaneously distilled off. After the addition was complete, the mixture was reacted for an additional 2 hours, cooled to 60 ° C and diluted with methanol (1650 mL). Subsequently, 227 ml of glacial acetic acid dissolved in 150 ml of methanol is added slowly, and the pigment precipitates. The product formed is filtered off at about 60 ° C and washed first with 3000 ml of methanol and then with 2000 ml of hot water. After drying under vacuum at 80 'C, 228.3 g (66% of the theoretical value for benzonitrile) of the pigment (VI) are obtained.

Example 49

Proceed exactly as in Example 48, but instead of diisopropyl ester of succinic acid.

(a) succinic acid dineopentyl ester,

b) succinic acid di-2-butyl ester,

(c) dicyclohexyl ester of succinic acid,

d) using succinic acid di-tert-butyl ester. The pigment of formula (VI) is thus obtained in the following yields (% of theoretical value for benzonitrile):

with ester of (a): 64.9%, ester of (b): 65.2%, ester of (c): 71.5%, ester of (d): 75.7%.

Example 50

The procedure was exactly the same as in Example 48, but with 30% by weight of both sodium and succinic diisopropyl ester. The pigment (VI) is thus obtained in a yield of 81.9% relative to the theoretical values for benzonitrile.

a mixture of benzonitrile (21 ml), di-tert-butyl ester of succinic acid (23 g) and toluene (20 ml) was added dropwise. The slurry was then stirred at 80-90 ° C for about 19 hours, then at 60 ° C, a mixture of 21 ml glacial acetic acid and 80 ml methanol was added dropwise over 1 hour and stirred for an additional 30 minutes. The pigment slurry was filtered at 60 ° C and washed first with methanol and then with water until they were level. After drying in a vacuum oven at 80 ° C, 23.8 g (82.5% of the theoretical value of succinic acid di-tert-butyl ester) of the pure pigment (VI) described in Example 1 are obtained.

Example 52 To a mixture of toluene (ml) was added 3.4 g of a 45% sodium / paraffin metal dispersion in argon gas and 14 ml of benzonitrile, 7.6 g of succinic acid tert-butyl ester and 27 ml of toluene were added dropwise over 2 hours. The temperature is slowly raised from 20 'C to 70' C and stirred for a further 20 hours at 80 ° C when 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 and washed with acetone and water until they are level. After drying in a vacuum oven at 80 'C, 5.6 g (58.9% of the theoretical value of succinic acid di-tert-butyl ester) of the pigment (VI) are obtained.

Example 53

The procedure described in Example 48 was followed, except that at the end of the reaction, 8% by weight hydrochloric acid was replaced with glacial acetic acid instead of methanol. After drying, 230 g (66.5% of the theoretical value of succinic acid diisopropyl ester) of the pure pigment (VI) are obtained.

54-57. example

15-37. The procedure described in Examples IV, however, is followed. The reaction conditions are set out in columns 2, 3 and 4 of Table IV and the starting material used is the nitrile of formula (IV) wherein R 'is the compound of formula IV. Table 1, Column 1. After drying under vacuum at 80 'C, the yield of the compound of formula (V) is given in the table, where R' is as defined in the table. The table also shows the hue obtained when the product is incorporated in PVC at a concentration of 0.2% by weight.

Example 51

To 100 ml of toluene was added 26.5 g of 2-methyl-2-butanol and 6.9 g of sodium under argon. The mixture is stirred at reflux (about 100 ° C) until the metal is completely dissolved and then at 70-80 ° C for 4-5 hours.

190,489

ARC. spreadsheet

Yield: Example dry R ' today reaction aggregatory tem- ture (° C) Beada- addition with time (Hours) (%) (Aho rostyánkö- acid diester into space vonatkozta- to theoretical value Hue at a concentration of 0.2% in PVC in comparison) 54th 4- (methylthio) - 110 2 62 reddish violet 55th 3-phenoxy 120 3 63 reddish orange 56th 4-Br 100 1.5 68 red 57th 4- (phenylthio) - 110 3 65 reddish violet

To demonstrate the advanced nature of the process of the present invention, a comparative experiment was carried out using the compound of formula VI prepared in Example 1 as described in Tetrahedron Letters, 1974, 2549-2552. by reacting benzonitrile and ethyl bromoacetic acid in the presence of an activated zinc copper catalyst.

One volume of copper acetate hydrate was dissolved in 25 volumes of glacial acetic acid in 90 ml of glacial acetic acid and 17.97 parts (0.274 mol) of zinc powder were added. The mixture was stirred vigorously for 1 minute and then filtered, washed with a small amount of glacial acetic acid and 75 volumes of xylene. The zinc thus activated was immediately transferred to a sulfurization flask with 40 volumes of xylene. 15-20 volumes of a mixture of 60 volumes of xylene, 28 volumes (0.27 mol) of benzonitrile and 30.4 volumes (0.27 mol) of bromoacetic acid 35 ethyl ester were dripped under argon atmosphere and heated slowly to 60 ° C. . An exothermic reaction occurred and the temperature of the contents of the flask rose rapidly to about 90 ° C. Thereafter, the temperature of the mixture was maintained at about 90 ° C by controlling the residual drip rate of the benzonitrile-bromoacetic acid-ethyl ester mixture. After the addition was complete, the reaction mixture was stirred at 90-95 for 2 hours. The argon was removed, air ₄₅ introduced into the mixture, the mixture was heated to reflux and stirred for 10 hours at this temperature.

It was then cooled to about 70 'C and about 100 volumes of acetone were added.

The precipitated product was filtered off at room temperature, washed with ₅₀ methanol and dried overnight at 80 ° C in vacuo. This gave 10.16 parts (26%) of crude product which is a mixture of 1,4-diceto-3,6-diphenylpyrrolo [3,4-c] pyrrole of Formula VI and poorly soluble organic zinc compounds which are not pigments. to use.

For purification, 3 parts by weight of this crude product were stirred for 2 hours at room temperature in 100 ml of dimethylformamide with about 1.8 volumes of 30% sodium methylate solution. After filtration to θθ, the filtrate was mixed with 3 volumes of glacial acetic acid, followed by 13 volumes of water, and the mixture was stirred overnight at room temperature. The next morning, the precipitate was filtered off, washed with dimethylformamide, ethanol, water and ethanol again and dried overnight at 80 ° C in vacuo. 1.5 parts of the above compound were obtained in the form of a red powder. Total yield: 13%.

Analysis for C _g H ₁₂ N ₂ O ₂ requires (molecular weight: 288.3): Calculated: C 74.99%, H 4.22%, N 9.72%; Found: C, 75.0; H, 4.4; N, 9.8.

_Λmax : 504 nm (in N-methylpyrrolidone), ε: 33,000.

Thus, it can be seen that the process according to the invention yields the product in much higher yields (~ 63%) and high purity, without the need for a separate purification process, whereas in the known process the crude product also needs to be purified and 13% overall.

Claims (5)

Claims A process for the preparation of 1,4-diketopyrrolo [3,4-c] pyrroles of formula I wherein R 1 and R ₂ are independently unsubstituted or mono- or disubstituted with halogen, or mono- or disubstituted with C 1 -C 4 alkyl. C 1-4 alkoxy, (C 1-4 alkoxy) carbonyl, cyano, trifluoromethyl, di (C 1-4 alkyl) amino, C 1-4 alkylthio, phenyl, a phenyl, naphthyl, furyl or thienyl monosubstituted with thio, phenoxy, phenyl or cyanophenyl, unsubstituted or substituted with C 1-8 alkoxy, characterized in that 1 mole of asymmetric or symmetric succinic acid ) ester, borostyánkősavdifenil ester or succinic diciklohexilésztert organic solvent, alkali metal, or alkali metal alkoxides as strong bases in the presence of 60 to 140 ° C at a temperature of, when R, and _R2 are the same je 2 moles of nitrile of formula (II) or (III) or, if R 1 and R _{2 are} different, 1 mol of nitrile of formula (II) and 1 mole of formula (III) and from the reaction product The compound of formula I is liberated by acid hydrolysis. Process according to claim 1, characterized in that the starting material is a uniform nitrile of formula (II) or (III). 3. The process according to claim 1, wherein the symmetric succinic diester is a symmetric succinic diester wherein the alkyl group is a chair or a tertiary alkyl group. A process according to claim 1, wherein the solvent is secondary or tertiary alcohol. 5. The process of claim 1 wherein the strong base is an alkali metal alcoholate.