MXPA97004174A - Process for preparing dicetopirrolopir derivatives - Google Patents

Abstract

The present invention relates to: This description relates to a process for preparing bis (hydroxymethyl) pyrrolopyrrole compounds of the formula (II) wherein A1 and A2 are aryl radicals, by reacting a 1,4-diketopyrrolopyrrole with formaldehyde or paraformaldehyde . The compound of the formula (II) can be isolated or further reacted in a synthesis of a container to give a compound of the formula (I) wherein B1 and B2 are organic radicals.

Description

PROCESS FOR PREPARING DERIVATIVES OF DICETOPIRROLOPIRROL This application refers to a process for preparing derivatives of 1,4-diketo-3,6-diarylpyrrolopyrrole wherein a diketopyrrolopyrrole is reacted with formaldehyde or paraformaldehyde to give a 2,5-bis (hydroxymethyl) -3,6-diarylpyrrolopyrrole-1,4-dione which is isolated or additionally reacted. Furthermore, this application relates to a process wherein a 2,5-bis (hydroxymethyl) -3,6-diarylpyrrolopyrrole-1,4-dione is reacted with a precursor of organic radicals B, and B2, a process wherein the precursor of the organic radicals B, and B2 is a 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole or a quinacridone, a 2,5-bis (hydroxymethyl) -3,6-diarylpyrrolopyrrole -1,4-dione, a process for its preparation, a diketopyrrolopyrrole derivative having two diaryldicetopyrrolopyrrole radicals as substituents, a pigment composition, a method for reducing the viscosity of a dispersion and a method for preparing a base coat finish / clear coating. The diaryldicetopyrrolopyrroles of the formula? or H - N N-H OR wherein Ai and A2 are aryl radicals well known as important pigments. The Patent of E.U.A. No. 4,585,878 discloses N-substituted derivatives of the diaryldicetopyrrolopyrrole pigments, which are useful as soluble polymer dyes or as pigments, wherein the N-substituent does not confer solubility in water. According to the Patent of E.U.A. No. 4,585,878, the N-substituted derivatives do not confer solubility in water. According to the Patent of E.U.A. DO NOT. 4,585,878, the N-substituted derivatives of the diaryldicetopyrrolopyrrole pigments are prepared by reacting a diaryldiphenyltopyrrolopyrrole compound in an organic solvent with a compound containing the boundary N-substituents attached to a leaving group, or reacting 2 moles of a compound of the formula RN- = CH-A, wherein r is the N-substituent and A is an aryl group, or one mole of every two different compounds of the formula RN = CH-A, with a diester of succinic acid in the presence of a base and an organic solvent and then dehydrogenating the product. Rheology enhancing agents for organic pigments reduce the viscosity of a dispersion of the organic pigment in an organic material of high molecular weight. Some compounds capable of functioning as rheology improving agents for organic pigments are known. For example, salts of phthalimidomethylquinacridone, of monosulfonic acid quinacridone, especially the aluminum salt, the derivative of dimethylaminopropylsulfonamide of quinacridone and pyrazolylmethylquinacridone are rheology improving agents for organic pigments. Although the known rheology-improving agents adequately reduce the viscosity when the organic pigment is dispersed in an organic material of high molecular weight, the incorporation of the known rheology-improving agents into a pigment composition based on a bright red or orange pigment highly saturated , generally results in unacceptable pigmentary properties with significant loss of color and color saturation. Therefore, it was the object of the present invention to provide rheology improving agents that do not exhibit the aforementioned drawbacks. Preferably, the rheology enhancing agents should be based on N-substituted diaryldyrtetopyrrolopyrroles. Consequently, a process for the preparation of a diketopyrrolopyrrole derivative of the formula (I) was found wherein AT and A2 are identical or different aryl radicals and B, and B2 are identical or different organic radicals; which contain diketopyrrolopyrol derivatives from 0 to 6 moles of -SO3M per mole of the diketopyrrolopyrrole derivative; wherein M is hydrogen or a metal or ammonium cation, which process comprises a reaction wherein a 1,4-diketo-3,6-diarylpyrrolopyrrole of the formula is reacted in a first step with formaldehyde or paraformaldehyde to give a sulfonated or non-sulphonated intermediate of the formula OR which reacts in a second step with a precursor of the organic radicals, BT and B2 to give the diketopyrrolopyrrole derivative of the formula (I). In addition, a process was also found wherein a 2,5-bis (hydroxymethyl) -3,5-diarylpyrrolopyrrole-1,4-dione is reacted with a precursor of organic radicals B and B2, a process wherein the precursor of the organic radicals B and B2 is a 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole or a quinacridone, a 2,5-bis (hydroxymethyl) -3,6-diarylpyrrolopyrrole-1, 4 -diona, a process for your preparation, a diketopyrrolopyrrole derivative having two quinacridone radicals as substituents, a diketopyrrolopyrrole derivative having two diaryldicetopyrrolopyrrole radicals as substituents, a pigment composition, a method for reducing the viscosity of a dispersion and a method for preparing a finished base coating / clear coating. The present invention relates to a process for preparing a variety of pigments of N-substituted derivatives of diaryldicetopyrrolopyrrole wherein the N-substituents are linked to diaryldicyclo-pyrrolopyrrole by the bonds -CH2- or -O-CH2-. The inventive process involves reacting a diaryldicetopyrrolopyrrole with formaldehyde or paraformaldehyde to give an intermediate of 2,5-bis (hydroxymethyl) -3,6-diarylpyrrolopyrrole-1,4-dione and further reacting the intermediate, with or without isolation with a second reagent that reacts with the hydroxymethyl groups. The reaction products are useful as dyes and as rheology improving agents for pigment dispersions. The intermediary of 2,5-bis (hydroxymethyl) -3,6-diarylpyrrolopyrrole-1,4-dione is useful as a synthesis for the preparation of a variety of DPP derivatives and as a stabilizer for polymers. In general, the second reagent reacts with the compound of the formula (II) by a substitution reaction to form a -O- linkage. The first step is preferably carried out by adding 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole to a solution of paraformaldehyde in concentrated sulfuric acid, preferably having a H 2 SO 4 concentration greater than 90 weight percent, more preferably above 95 weight percent. In general, the stoichiometric amount of formaldehyde or paraformaldehyde (calculated as formaldehyde) is used in the first step. Therefore, the molar ratio of 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole to formaldehyde or paraformaldehyde (calculated as formaldehyde) during the first step is usually on the 0.75: 2 scale at 1.25 to 2, preferably 1: 2. After the first step is completed, the resulting intermediate is reacted with the precursor to produce the diketopyrrolopyrrole derivative of the formula (I). Preferably, both steps are carried out at a temperature of 20 to 100 ° C. If a high degree of sulfonation is desired, the process is carried out at higher temperatures, for example, above 40 ° C. If it is desirable to have a low degree of sulfonation, the reaction is maintained at a lower temperature, preferably 40 ° C or less. After the reaction is complete, the 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole derivative is usually isolated by procedures conventionally used in the art to isolate 1,4-diketo-3, 6-diarylpyrrolo [3,4-c] pyrroles, in particular by pouring the sulfuric acid solution into ice water keeping the temperature below 10 ° C and stirring the resulting aqueous slurry for about 1 hour, followed by filtration, washing and drying to give the derivative of 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole in solid form. Since it is not necessary to isolate the intermediate, the process of the invention is preferably a container process. Nevertheless, it is possible to isolate the intermediate before carrying out the second step, especially, for example, in cases where it is desired to carry out the second step in a solvent other than the solvent used for the first step. Suitable solvents for the second step include concentrated sulfuric acid, polyphosphoric acid, and organic solvents which react with the compound of the formula (II), especially polar organic solvents such as acetonitrile, benzonitrile, dimethylformamide, dimethyl sulfoxide, tetramethylene sulfone. It is also possible to carry out the second step in a solvent which reacts with the compound of the formula (II) to produce the desired product, for example, the C1-C10 alcohols are suitable solvents if the compound of the formula (I) it is ether obtainable by the reaction of the compound of the formula (II) with the alcohol. In a preferred embodiment of the present invention, 1,4-diketo-3,6-diarylpyrrolopyrrole of the formula (II) is reacted with a precursor of the organic radicals, B1 and B2.

Preferably, the diketopyrrolopyrrole derivatives of the formula (I) contain from 0 to 4 moles of -SO3M per mole of diketopyrrolopyrrole derivative; more preferably from 0 to 2 moles per mole of diketopyrrolopyrrole derivative. In general, if the reaction is carried out at about 50 ° C, the product contains about 0.5 moles of -SO3M per mole of diketopyrrolopyrrole derivative. M is preferably hydrogen or an alkali metal, such as sodium or potassium, an alkaline earth metal, such as magnesium, an aluminum, a zinc or an ammonium cation. Examples of suitable ammonium cations include quaternary ammonium cations, such as trimethylcetylammonium or tributylbenzylammonium. Ai and A2 as aryl include aromatic and heteroaromatic radicals. Radicals that are particularly suitable as Ai and A2 include radicals of the formula wherein Ri and R2 are each independently of the other, hydrogen, halogen, C1-C18 alkyl, C1-C18 alkoxy, C1-C16 alkyl mercapto, C1-C18 alkylamino, C1-C18 alkoxycarbonyl, C1- C18 alkylaminocarbonyl, C18, -CN, -NO2, trifluoromethyl, C5-C6 cycloalkyl, -CH = N- (C1-C18 alkyl), phenyl, imidazolyl, pyrazolyl, triazolyl, piperazinyl, pyrrolyl, oxazolyl, benzoxazolyl, benzothiazolyl, benzimidazolyl, morpholinyl, piperidinyl or pi rrolidi nyl, B is -CH2-, -CH (CHj) -, -C (CH3) 2-, -CH = N-, N = N-, -O-, -S-, -SO-, R3 and R4 are each independently of the other, hydrogen, halogen, d-C6 alkyl, C1-C18 alkoxy or -CN, R5 and R6 are each independently of the other hydrogen, halogen or C6-C6 alkyl, and R7 is hydrogen or CrC6 alkyl. In particular, A ^ and A2 are each a group of the formula wherein Ri and R2 are each independently of the other, hydrogen, chlorine, bromine, C? -C alkyl, alkoxy, C? -C6 alkylamino, phenyl or CN, G is -O-, -NR7, -N = N- or -SO2-, R3 and R4 are hydrogen and R is hydrogen, methyl or ethyl, and more particularly AT and A2 they are each a group of the formula wherein Ri and R2 are each independently of the other, hydrogen, methyl, tertiary butyl, chlorine, bromine, phenyl or CN. At least one of Ri and R2 is hydrogen and the other is in the 3 or 4 position of the phenyl ring. According to the present invention, the organic radicals Bi and B2 are derived from a precursor that reacts with the hydroxy groups of a compound of the formula (II) either by a substitution reaction or to form a -O- bond. Precursors that react with a hydroxyl group by a substitution reaction generally with compounds comprising an aromatic radical, a heteroaromatic radical, or radicals of the formula XC (= O) -Y-, -YC (= O) -OX, XC (= S) -Y-, -YC (= S) -OX, -YC (= S) -SX, XC (= N) -Y-, XZN-, ZS-, X-S02-, X-O2-NR10-, and -N (R? o) -C (= O) -O-X; wherein X and Z are each hydrogen or an aliphatic, alicyclic, araliphatic, aromatic or heterocyclic radical, or X and Z together form a 3 to 8 membered ring, Y is the residue of a portion containing active methylene and Rio is hydrogen, an aliphatic radical, an alicyclic radical, an araliphatic radical, an aromatic radical or a heterocyclic radical, or Rio and X together form a 3- to 8-membered ring. Examples of radicals of Bi and B2 derivable from a precursor that reacts with a hydroxyl group to form a -O- linkage include an alkyl halide and radicals of the formula XC (= O) -, XC (= S) O-, X-SO2-O-, XO-; where X has the meaning given before.

As aromatic radicals, B, and B2 especially include radicals containing 1, 2, 3, 4 or more phenyl rings that are directly linked to one another, linked together by a linking group, fused or any combination thereof . The biphenyl radical is an example of two phenyl rings directly linked to one another. The radicals of the formula where Gi is a linking group, are examples of phenyl rings linked to each other, through a linking group. Examples of aromatic radicals containing fused phenyl rings include naphthyl, anthryl and phenanthryl. The linking group d especially are those linking groups described above for the variable G. As heteroaromatic radicals, and B2 include especially radicals containing one or more rings of 5, 6 or 7 members containing from 1 to 4 heteroatoms. In general, the heteroatoms are nitrogen, oxygen, sulfur or any combination thereof. Suitable heteroaromatic radicals include pyrrolopyrroles, especially 1,4-diketo-3,6-diarylpyrrolo [3,4-cjpyrroles and quinacridones. Preferably, Y is the residue of a portion containing active methylene. The portions of methylene active generally in those methylene groups that are attached to an electron withdrawing substituent, such as a carbonyl or nitrile substituent. In general, the active methylene portions participate in a Mannich type reaction or the like. In general, Y is -CHX, -XH2X, - (CH = CH) n-CH2-X, where n is 1, 2, or 3. When Y is the radical -CHX-, the radical -CHX- is part of a ring, for example, when Bi or B2 is the radical XC (= O) -Y-, X and Y can be part of, for example, a cyclohexanone ring. X and Z are usually aliphatic, alicyclic, araliphatic, aromatic or heterocyclic radicals.

In general, aliphatic radicals include C 1 -C 10 alkyl radicals, C 1 -C 10 alkenyl, and C 1 -C 10 alkynyl, including straight and branched chains. Alicyclic radicals include those portions that contain only one or more rings of non-aromatic hydrocarbons. Important alicyclic radicals include radicals derived from C3-C8 cycloalkanes and C3-C8 cycloalkenes. Examples of important alicyclic radicals include cyclopentyl, cyclohexyl and cycloheptyl. Alicyclic radicals also include those portions wherein there is, for example, a -C (= O) - in the ring, such as cyclohexanone. Araliphatic radicals are those portions containing an aliphatic portion and an aromatic portion, for example, a phenyl or a heteroaromatic portion. Examples of araliphatic radicals include radicals derived from phenylalcanic acids, naphthylalkane acids, pyridinalcanoic acids, quinolinalcanoic acids, indole-alkanoic acids, such as those derived from phenyl acetic acid, phenylpropionic acid, or indole acetic acid. Suitable aromatic radicals such as X and Z include those described above for being useful as Bt and B2. The term, "aromatic" radical, does not include heteroaromatic radicals. Heterocyclic radicals contain one or more non-aromatic and / or aromatic rings containing one or more heteroatoms; especially rings of 3 to 8 members that contain from 1 to 3 heteroatoms, whose heteroatoms are especially nitrogen, sulfur and oxygen. The term "heterocyclic radical" includes fused ring systems wherein one or more rings contain one or more heteroatoms. Important heterocyclic radicals include pridinyl, pyranyl, tetrahydrofuranyl, morpholino, pyrimidyl, pyrone, oxazine, azepinyl, triazinyl, oxathiazinyl, prirrolyl, benzofuranyl, piperazinyl, oxathiazolyl, oxadiazolyl, quinolinyl, indolyl, carbazolyl, xanthenyl, acridinyl, coumarinyl, benzoxazolyl, benzopyrone. , quinazolinyl. Heterocyclic radicals include those wherein the ring is a lactone or a lactam. The description of the above radicals also defines aliphatic, alicyclic, araliphatic, aromatic and hetrocyclic radicals suitable as R10. When Rio is combined with X to form a ring, the ring is preferably a five or six membered ring. The aromatic, heterocyclic, aliphatic, alicyclic and araliphatic radicals are unsubstituted (by any group other than hydrogen) or substituted by one or more, preferably from 0 to 4, common substituents. Common substituents include hydroxy, carbonyl, halogen, C 1 -C 18 alkyl, C 1 -C 18 alkoxy, C 1 -C 8 alkylmercapto, C 1 -C 18 alkylamino, C 1 -C 18 alkyl amino, alkoxycarbonyl of C 1 -C 18, C 1 -C 18 alkylaminocarbonyl, -CN. -N02, trifluoromethyl, C5-C6 cycloalkyl, -C = N- (C? -C? Alkyl), phenyl, wherein the alkyl groups can be further substituted by hydroxyl, halogen, nitro, Ct-Ce alkoxy, carbonyl, -CN. Substituents defined as halogen are usually iodo, fluoro, bromo and preferably chloro; the C? -C6 alkyl is usually methyl, ethyl, n-propyl, isopropyl, n-butyl, secbutyl, tertiary butyl, n-amino, tertiary amino, hexyl and C1-C10 alkyl and C1-C18 alkyl are also usually heptyl, octyl, 2-ethylhexyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl or dodecyl. C 1 -C 18 alkoxy, also in C 1 -C 18 alkoxycarbonyl, is usually methoxy, ethoxy, n-propoxy, isopropyloxy, butoxy, hexyloxy, decyloxy, dodecyloxy, hexadecyloxy or octadecyloxy. The C 1 -C 18 alkyl mercapto is, for example, mercapto methyl, mercapto ethyl, mercaptopropyl, mercapto butyl, mercapto octyl, mercapto decyl, mercapto hexadecyl or mercapto octadecyl. C 1 -C 18 alkylamino, also in C 1 -C 18 alkylaminocarbonyl, is usually methylamino, ethylamino, propylamino, hexylamino, disillusion, hexadecylamino or octadecylamino. C5-C6 cycloalkyl is usually cyclopentyl and cyclohexyl. Important radicals containing the residue of an active methylene, Y, include radicals which are derived from various acetoacetanilides, cyanoacetanilides and benzoacetanilides, such as ethyl acetoacetate, ethyl malonate, ethyl cyanoacetate, ethyl benzoylacetate and malononitrile.

Important radicals of the formula XC (= O) -O- include esters derivable from aliphatic acids of d-C2, such as acetic acid, stearic acid, oleic acid, linoleic acid, acrylic acid, methacrylic acid or trifluoroacetic acid, an acid Ci-C2 araliphatic, such as benzoic acid, phenylacetic acid, phenylpropionic acid or indoleacetic acid, a resin acid such as abeitic acid, behemic acid, a naphthenic acid, a dimeric acid, wherein the aliphatic acids and araliphatic acids are not replaced or replaced by one or more common substituents. Important radicals of the formula XC (= O) NR10- and X-S02- NR10- include those derivable from amides and sulfonamides prepared from an aliphatic amine and an aliphatic carboxylic or sulfonic acid, an aromatic amine and an aliphatic carboxylic or sulfonic acid , or an aromatic amine and an aromatic or araliphatic carboxylic or sulfonic acid. Suitable radicals of the formula XC (= O) NR10 especially include those in which x is C? -C2 alkyl, phenyl, benzyl, tolyl, naphthyl and R10 is hydrogen, methyl, ethyl, n-propyl, isopropyl, phenyl, benzyl The important radicals of the formulas X-SO2, X-SO2-O- and XC (= S) -O- include those wherein X is an aliphatic radical of d-C24, an aromatic radical of C6-C18, an araliphatic radical of d-C2, a 5, 6 or 7 membered heterocyclic ring, or a fused ring system containing a 5, 6, or 7 membered heterocyclic ring, or a fused ring system containing a heterocyclic ring of 5, 6 or 7 members, such as pentyl, hexyl, phenyl, benzyl, tolyl, naphthyl, pyridinyl or indolyl. Important radicals of the formula X-SO2-O- include those derivable from p-toluenesulfonic acid, naphthalenesulfonic acid, pentanesulfonic acid or a water-soluble dye containing a group which is solubilized in water of -SO3H. Important radicals of the formula XZN- include those derivable from N, N-dialkyl amines of C-C24, such as dimethylamine, diethylamine, dipropylane and dibutylamine, arylamine, such as NN-diphenylamine, aralkylamine, such as N, N-dibenzylamine or ethylphenylamine, or heteroarylamines, such as aminopyridine. The formula XZN- also includes those radicals in which X and Z together, together with the nitrogen atom, form a 3- to 8-membered ring, especially a 5- or 6-membered ring, such as a piperazine ring, morpholine, thiomorpholine , pyrrolidine or piperidine. The important radicals of the formula XO- include those in which X is an aliphatic radical of C? -C24, an alicyclic radical of C5-C10, phenyl, benzyl, naphthyl, or a radical H- (CH2CHRnO) m -CH2CHRn-, wherein Rn is hydrogen or methyl, especially hydrogen, and m is a number from 1 to 20. The important radicals of the formula XS- include those wherein X is an aliphatic radical of C? -C24, an alicyclic radical of C5-C10, phenyl, benzyl and naphthyl. The important radicals of the formula include radicals derivable from succinimide, glutarimide, phthalimide, naphthalimide and isoquinoline-1,3-dione. Important radicals of the formula -N (R? 0) -C (= O) -OX include those wherein R10 is hydrogen, d-C6 alkyl, phenyl or benzyl, especially hydrogen and C? -C6 alkyl, and X is C6-C6 alkyl, for example, urethane. Aromatic and heteroaromatic radicals derivable from known dyes, such as azo dyes, azomethine, or fiber reactants, for example triazine dyes, or known organic pigments, such as diketopyrrolopyrrole radicals, quinaceridone, phthalocyanine, indatrone, isoindoline, isoindolone, flavantrone, pyrantrone, anthraquinone, thioindigo, perylene and dioxazine, are radicals suitable for B, and B2. The radicals of quinacridinil (derived from a quinacridone) and 1,4-diketo-3,6-diarylpyrrolo [3,4-cjpirrolilo (derivative of a 1,4-diketo-3,6-dicarilopyrrolo [3,4-c] pyrrole) are radicals especially suitable for B and B2. Therefore, one aspect of the present invention relates to a process for preparing diketopyrrolopyrrole derivatives of the formula (I) wherein BT and B2 are each a pigment portion, in particular, a pigment portion of diketopyrrolopyrrole, quinacridone, phthalocyanine, indantrone, isoindoline, isoindolone, flavantrone, pyrantrone, anthraquinone, thioindigo, perylene and dioxazine.

The 1, 4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrolyl radicals are especially suitable radicals for Bi and B2. Said radicals are derivable from compounds of the formula which are well known as pigments, preferably used Or as a radical. When Bi and B2 are 1, 4-diketo-3,6-diarylpyrrolo [3,4-cjpyrrolyl radicals, the preferences described above for Ai and A2 apply. Another aspect of this invention relates to a process for preparing diketopyrrolopyrrole derivatives of the formula (I) wherein Bi and B2 are quinacridinyl radicals said radicals are derived from the compounds of the formula wherein each R is independently hydrogen, halogen, carboxyl, unsubstituted d-C6 alkyl or d-C6 alkoxy which is substituted by halogen. and B2 especially are radicals derivable from quinacridone, 2,9-dichloroquinacridone, 4,11-dichloroquinacridone, 2,9-dichloroquinacridone, 4,11-dichloroquinacridone, 2,9-dimethylquinacridone, 4,11-dimethylquinacridone, 2,9-difluoroquinacridone . The present invention also relates to a compound of the formula OR containing from 0 to 6 moles of -SO3M per mole of the compound, wherein Ai and A2 are identical or different aryl radicals and M is hydrogen or a metal or ammonium cation. AT and A2 have the meaning given before.

Preferably Ai and A2 are radicals of the formula wherein Ri and R2 are each independently of the other, hydrogen, halogen, C1-C18 alkyl, C1-C18 alkoxy, C1-C? alkyl alkyl mercapto, d-C18 alkylamino, C? -C18 alkoxycarbonyl, alkylaminocarbonyl of C1-C18, -CN, -NO2, trifluoromethyl, C3-C6 cycloalkyl, -CH = N- (C1-C18 alkyl), phenyl, imidazolyl, pyrazolyl, triazolyl, piperazinyl, pyrrolyl, oxazolyl, benzoxazolyl, benzothiazolyl, benzimidazolyl, morpholinyl, piperidinyl or pyrrolidinyl, B is -CH2-, -CH (CH3) -, -C (CH3) 2-, -CH = N- , N = N-, -O-, -S-, -SO-, -SO2-, -CONH- or -NR7-, R3 and R4 are each independently of the other, hydrogen, halogen, C? -C6 alkyl, C1-C18 alkoxy or -CN, Rs and R6 are each independently of the other hydrogen, halogen or C? -C6 alkyl, and R7 is hydrogen or dC6 alkyl. Preferably Ai and A2 are radicals of the formula wherein R1 and R2 are each independently of the other, hydrogen, chlorine, bromine, C? -C4 alkyl, C? -C6 alkoxy, C? -C6 alkyl, phenyl or CN, G is -O-, - NR7, -N = N- or -SO2-, R3 and R are hydrogen and R7 is hydrogen, methyl or ethyl. More preferably, Ai and A2 are radicals of the formula wherein Ri and R2 are each independently of the other, hydrogen, methyl, tertiary butyl, chlorine, bromine, phenyl or CN. Preferably, at least one of Ri and R2 is hydrogen. Preferably, the compounds of the formula (II) have from 0 to 4 moles of -SO3M, more preferably from 0 to 2 moles of -SO3M. The present invention also relates to a process for preparing a compound of the formula containing from 0 to 6 moles of -SO3M per mole of the compound, wherein A, and A2 are identical or different aryl radicals and M is hydrogen or a metal or ammonium cation; said process comprises reacting a 1,4-diketo-3,6-diarylpyrrolopyrrole of the formula with formaldehyde or paraformaldehyde. The preferences discussed above with reference to the first step of the process for preparing the compounds of the formula (I) are applicable to this aspect of the invention as well.

In particular, the present invention relates to the process wherein 1,4-diketo-3,6-diarylpyrrolopyrrole is combined with paraformaldehyde in concentrated sulfuric acid; especially wherein 1, 4-diketo-3,6-diarylpyrrolopyrrole and formaldehyde (or paraformaldehyde, calculated as formaldehyde) are present in a molar ratio in the range of 0.75: 2 to 1.25: 2, more preferably of about 1: 2. . If less sulfonation is desired, the reaction is preferably carried out at a temperature of 40 ° C or less. The reaction generally proceeds at higher temperatures, for example, on the scale of about 20 to 120 ° C, but higher temperatures generally lead to a higher degree of sulfonation; which may desirably depend on the intended use of the final product. The hydroxymethyl derivative of the formula (II) is generally isolated by precipitation and filtration, for example, extracting in an organic solvent or water followed by filtration. Another preferred aspect of the present invention relates to a diketopyrrolopyrrole derivative of the formula (la) B and B2 = QA) wherein Ai and A2 are identical or different aryl radicals, having the meaning given above, and QA is a quinacridone radical; said pyrrolopyrrole derivative is substituted from 0 to 6 moles of -SO3M per mole of the pyrrolopyrrole derivative; wherein M is hydrogen or a metal or ammonium cation as previously defined. Preferably, the pyrrolopyrrole derivative is substituted with from 0 to 2 moles of -SO3M per mole of DPP derivative, more preferably from 0 to 0.75 moles of -SO3M per mole of derivative of DPP. Particularly preferred pyrrolopyrrole derivatives virtually do not contain -SO3M. The preferences described above for A and A2 apply. In a preferred embodiment of the present invention, AT and A2 are phenyl or tertiary-4-butyl-phenyl. QA preferably is a quinacridone radical of the formula (III) wherein each R is a common substituent; preferably at positions 2 and 9 or 4 and 11. Preferably, each R is independently hydrogen, halogen, carboxyl, unsubstituted d-C6 alkyl, d-C6 alkyl which is substituted by halogen, unsubstituted d-C6 alkoxy or C6-C6 alkoxy which is substituted by halogen. Preferably, QA is a quinacridone radical which is derived from quinacridone, 2,9-dichloroquinacridone, 4,11-dichloroquinacridone, 2,9-dimethylquinacridone, 4,11-dimethylquinacridone, 2,9-difluoroquinacridone. Therefore, preferred QA substituents are quinacrodone radicals of the formula (III) wherein each R and hydrogen, Cl, F, or -CH3-.

Preferably, if both substituents R are not hydrogen, both substituents R are the same and are selected from the group consisting of Cl, F or -CH3 and more preferably at positions 2, 9 or 4, 11.

Alternatively, both R substituents are hydrogen. Particularly important compounds are those in which Ai and A2 are identical and are selected from the group consisting of phenyl, 4-methylphenyl, 4-tert-butylphenyl, 4-chlorophenyl, 4-bromophenyl and biphenyl-1-yl (4-phenyl) -phenyl); especially those compounds wherein both R substituents on the QA radical of the formula (III) are hydrogen. In a particularly preferred embodiment of the present invention, the most preferred compounds are those pyrrolopyrrole derivatives of the formula (Ia) wherein Ai and A2 are each a group of the formula wherein Ri and R2 are each independently of the other, hydrogen, methyl, tertiary butyl, chloro, bromo, phenyl or CN; and QA is a radical of the formula wherein the substituents R are hydrogen, 2,9- or 4,11-dichloro, 2,9- or 4,11-difluoro or 2,9-, or 4,11-dimethyl. Another preferred aspect of the present invention relates to a pyrrolopyrrole derivative of the formula (Ib) B ^ and B2 = DPP) or wherein Ai and A2 are identical or different aryl radicals, having the meaning given above, and DPP is a diaryldicetopyrolopyrrole radical; said diketopyrrolopyrrole derivative is substituted with from 0 to 6 moles of -SO3M per mole of the derivative of pyrrolopyrrole; wherein M is hydrogen or a metal or ammonium cation. Preferably, the pyrrolopyrrole derivative is substituted with from 0 to 2 moles of -SO3M per mole of DPO derivative, more preferably from 0 to 0.75 moles of -SO3M per mole of DPP derivative. Particularly preferred pyrrolopyrrole derivatives virtually do not contain -SO3M. Preferably, DPP is a diaryldicyclo-pyrrolopyrrole radical of the formula wherein A3 and A4 are aryl radicals and have the same meaning as Ai and A2 as defined above. The preferences described above apply for AT and A2, also, for A3 and A4. Preferred compounds are those in which Ai and A2 are identical and are selected from the group consisting of phenyl, 4-methylphenyl, 4-tert-butylphenyl, 4-chlorophenyl, 4-bromophenyl and bif eni I-1-yl (4-phenyl- phenyl), especially those in which A3 and A4 are also identical and are selected from the group consisting of phenyl, 4-methylphenyl, 4-tert-butylphenyl, 4-chlorophenyl, 4-bromophenyl and biphenyl-1-yl.

A preferred class of pyrrolopyrrole derivatives are those wherein A3 and A are each 4-tert-butylf-enyl; especially those in which Ai and A2 are identical and are selected from phenyl, 4-tert-butylphenyl and 4-methylphenyl; especially 4-tert-butylphenyl. Said pyrrolopyrrole derivatives provide excellent rheology enhancement properties when incorporated into a pigment composition, but additionally provide increased properties of suitable pigments such as concealment (opacity) and color saturation. Thus, the pyrrolopyrrole derivative wherein Ai, A2, A3, and A4 are each 4-tert-butylphenyl, represents an especially preferred compound of the present invention. Another preferred class of pyrrolopyrrole derivatives are those wherein A3 and A4 are each 4-methylphenyl; and Ai and A2 are identical and are selected from the group consisting of phenyl, 4-tert-butylphenyl and 4-methylphenyl; especially 4-tert-butylphenyl. The pyrrolopyrrole derivatives of the present invention are especially suitable for use as rheology improving agents for organic pigments. As rheology enhancing agents for organic pigments, the pyrrolopyrrole derivatives of the invention function to reduce the viscosity of a dispersion of the pigment composition in a high molecular weight organic material, such as a coating composition, eg, a paint for cars soluble in water or soluble in solvents.

Therefore, another aspect of this invention relates to pigment compositions comprising an organic pigment and a pyrrolopyrrole derivative of the formulas (I, la and / or Ib). Preferably, the pigment composition contains 0.1 to 20 weight percent of the pyrrolopyrrole derivative. More preferably, the pigment composition contains from 1 to 10 weight percent of the pyrrolopyrrole derivative. Preferably, the pyrrolopyrrole derivative of the formulas (I, la and Ib) are selected such that Ai, A2, A3 and A are each a group of the formula wherein Ri and R2 are each independently of the other, hydrogen, methyl, tertiary butyl, chlorine, bromine, phenyl or CN. At least one of Ri and R2 is preferably hydrogen. More preferably, at least one of Ri and R2 is hydrogen and the other is in the 3 or 4 position of the phenyl ring. The important pigment compositions according to the present invention are those which contain a pigment of 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole or a quinacridone pigment as the organic pigment including its solutions solids and a pyrrolopyrrole derivative of the formulas (I, la and / or Ib).

The pigment compositions of the invention especially include those containing a pigment of 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole, 1,4-diketo-3,6-di (3- or 4-chlorophenyl) pyrrolo- [3, 4-c] pyrrole, 1,4-diketo-3,6-di (3,4-dichlorophenyl) pyrrolo [3,4-c] pyrrole, 1,4-diketo-3 , 6-di (biphenyl-1-yl) pyrrolo [3,4-c] pyrrole, a pyrrolopyrrole derivative of the formulas (I, la and / or Ib). In addition, the pigment compositions of the invention especially include those containing a quinacridone pigment selected from the group consisting of unsubstituted quinacridone, 2,9- and 4,11-dimethylquinacridone, 2,9- and 4,11-dichloroquinacridone and 2,9- and 4,11-difluoroquinacridone and a pyrrolopyrrole derivative of the formulas (I, la and / or Ib). Particularly important pigment compositions are those containing a pigment of 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole selected from the group consisting of 1,4-diketo-3,6-dif in ilpyrrolo [3,4-c] pyrrole and 1,4-diketo-3,6-di (4-tert-butylphenyl) pyrrolo- [3,4-c] pyrrole in combination with a pyrrolopyrrole derivative of the formulas (I , and / or la), and / or of the formula (Ib) wherein A3 and A are each 4-tert-butylphenyl, especially those in which in addition Ai and A2 are identical and are selected from phenyl, 4-tert-butylphenyl and 4- methylphenyl; especially 4-tert-butylphenyl, more preferably, if the organic pigment is red or orange or where A3 and A4 are each 4-methylphenyl, especially those wherein Ai and A2 are also identical and are selected from phenyl, 4-tert-butylphenyl and 4-methylphenyl; especially, 4-tert-butyl-enyl. Although the pigment compositions of the present invention may consist only of the organic pigment and the pyrrolopyrrole derivative, the pigment compositions generally contain common additives, such as texture improving agents, light stabilizers and especially a second rheology enhancing agent. In this application, the term "pigment composition" preferably means a formulation to be dispersed in a high molecular weight organic material that is composed of the pigment, the pyrrolopyrrole derivatives and any optional additives. Useful light stabilizers are U.V. light absorbers, for example, benzotriazoles or hidden amine light stabilizers (ELAO). Texture improving agents are especially useful as an additional component that can improve the properties of agitation pigment compositions. Suitable texture improvers include fatty acids having at least 12 carbon atoms and amides, esters or salts of fatty acids. Texture enhancers derived from normal fatty acid include fatty acids such as stearic acid or behenic acid and fatty amines such as laurylamine or stearylamine. In addition, polyols, such as aliphatic 1,2-diols or polyvinyl alcohol and ethoxylated fatty alcohols, soybean oil Expoxed, resin acids, resin salts are suitable texture improvers before. Resin acids and resin acid salts are especially suitable texture improvers. In general, the pigment compositions of the invention contain from 0 to 20 weight percent of the texture improving agent, preferably from 0.5 to 10 weight percent. Agents useful as the second rheology enhancing agent in the present pigment compositions include quinacridone derivatives, such as, quinacridone sulfonic acid, or a salt thereof, especially the aluminum salt, or pyrazolylmethylquinacridone, or other derivatives thereof. pyrrolopyrrole (DPP), such as, a sulfonic acid of DPP or a salt thereof, or another DPP derivative of formula I. If the pigment composition includes a second rheology enhancing agent, the combined parts by weight of the derivative of pyrrolopyrrole of the formulas (I, la and / or Ib) and the second rheology enhancing agent preferably are in the range of 0.2 to 20 parts by weight by the pigment; more preferably from 2 to 10 parts per part of the pigment. As discussed above, the presence of a pyrrolopyrrole derivative of the invention in a dispersion of an organic pigment in an organic material of high molecular weight effectively reduces the viscosity of the dispersion. Therefore, the present invention also relates to a method for reducing the viscosity of a dispersion of an organic pigment in a high molecular weight organic material comprising incorporating an effective viscosity reducing amount of a pyrrolopyrrole derivative of the formulas (I, la and / or Ib) into the dispersion. The pyrrolopyrrole derivative of the formulas (I, la and / or Ib) is added to the dispersion as such, or preferably as a component of a pigment composition. Preferably, the pyrrolopyrrole derivative of the formulas (I, la and Ib) are selected such that Ai, A2, A3 and A4 are each a group of the formula wherein Ri and R2 are each independently of the other, hydrogen, methyl, tertiary butyl, chlorine, bromine, phenyl or CN. At least one of R, and R2 preferably is hydrogen. More preferably, at least one of Ri and R2 is hydrogen and the other is in the 3 or 4 position of the phenyl ring. Preferably, the pyrrolopyrrole derivative of the formulas (I, la and / or Ib) are present in the dispersion in an amount in the scale from 0.1 to 2 parts by weight by the pigment dispersion. Preferably, the pyrrolopyrrole derivative of the formulas (I, la and / or Ib) are present in the dispersion in a amount on the scale of 0.2 to 10 parts by weight on the part of the pigment dispersion. If the pyrrolopyrrole derivative of the formulas (I, la, and / or Ib) are combined with a second rheology enhancing agent, the combined parts by weight of the pyrrolopyrrole derivative of the formulas (I, la and / or Ib) and the second rheology enhancing agent preferably are in the range of 0.1 to 20 parts by weight from the pigment dispersion; more preferably from 0.2 to 10 parts by the pigment dispersion. The organic pigment is azo pigment, zomethin, anthraquinone, phthalocyanine, perinone, perylene, 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole, thioindigo, isoindole, isoindolinone, quinacridone, flavantrone, indantrone, anthrapyrimidine and quinophthalone; in particular a pigment of 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole or quinacridone or a mixture thereof. High molecular weight organic materials are, for example, cellulose ethers, cellulose esters, polyurethanes, polyesters, polycarbonates, polyolefins, polystyrene, polysulfones, polyamides, polycycloamides, polyimides, polyethers, polyether ketones, polyvinyl halides, polytetrafluoroethylene, acrylic and methacrylic polymers, rubber, silicone polymers, phenyl / formaldehyde resins, melamine, formaldehyde resins, urea / formaldehyde resins, epoxy resins and diene rubbers or copolymers thereof.

The dispersions especially contain a high molecular weight organic material which is useful for heating heat curable or interlaxable coatings, for example chemically reactive coatings, including baked finishes containing the common binders and which are reactive at high temperature. Examples of the high molecular weight oganic materials that are used in such coatings include acrylic, alkyd, epoxy, phenolic, melamine, urea, polyester, polyurethane, blocked isocyanate, benzoguanamine or cellulose resins, or combinations thereof. . High molecular weight, pigmented organic materials prepared according to the present process are also useful as air drying or physically drying coatings, for example, conventional lacquers such as those used in the cosmetics industry as nail varnishes, for example nitrocellulose lacquers. The present process is particularly suitable for reducing the viscosity of dispersions containing high molecular weight organic materials conventionally employed as finishes in the automotive industry, especially acrylic / melamine resin systems, alkyd resin / melamine or thermoplastic acrylic resin, as well as water-based coating systems. The use of many reduced viscosity reducing agents for pigment dispersions often results in at least some loss of saturation when the dispersion of Pigments are applied as the base coat of an automotive finish basecoat / clearcoat. However, the use of the pyrrolopyrrole derivatives present of the formulas (I, la, and / or Ib) as viscosity reducing agents surprisingly does not result in loss of saturation when the pigment dispersion is applied as to the coating of ase in an automotive base coat / clear coat finish, in many cases the saturation of the finish is actually increased by the presence of the pyrrolopyrrole derivative of the formulas (I, la and / or Ib). Therefore, the present invention furthermore relates to a method for preparing a base coat / clear coat finish, comprising the step of applying a dispersion comprising an effective amount of viscosity reduction and saturation increase of a derivative of pyrrolopyrrole of the formulas (I, la and / or Ib) in an organic compound of high molecular weight to a substrate; especially wherein in the compound of the formula (Ib) A3 and A are each 4-tert-butyl-enyl; and Ai and A2 are identical and are selected from the group consisting of phenyl, 4-tert-butylphenyl and 4-methylphenyl; especially 4-tert-butylphenyl.

Another preferred embodiment relates to a method for preparing a basecoat / clearcoat finish, comprising the step of applying a dispersion comprising an organic pigment and an effective viscosity reducing amount. of a pyrrolopyrrole derivative of the formulas (I, la, Ib) in an organic compound of high molecular weight to a substrate. A preferred embodiment of the present invention relates to a coating composition, such as an automotive topcoat, which comprises an organic material of high molecular weight, a red or orange organic pigment and a pyrrolopyrrole derivative of the formula ( Ib) wherein A3 and A are each 4-tert-butylphenyl; especially those in which Ai and A2 are identical and are selected from phenyl, 4-tert-butylphenyl and 4-methylphenyl; especially phenyl or 4-tert-butylphenyl. In addition, a preferred embodiment of this invention includes a coating composition comprising an organic material of high molecular weight, an orange colored organic pigment and a pyrrolopyrrole derivative of the formula (Ib) wherein Ai, A2 , A3 and A4 are each phenyl, or A, and A2 are phenyl and A3 and A4 are each 4-tert-butylphenyl. Preferably, the red or orange organic pigment is selected from the group consisting of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole and 1,4-diketo-3,6-di ( 4-tert-butylphenyl) pyrrolo [3,4-c] pi rrol. Preferably, the high molecular weight organic material is an acrylic / melamine resin, alkali resin / melamine or thermoplastic acrylic resin.

The preferences discussed above for the pyrrolopyrrole derivatives refer to the other aspects of this invention. In this application, the term "automotive finish" is used to describe finishes normally used for automobiles, such as water-soluble and solvent-soluble finishes of base coatings / clear coatings. These finishes are used for numerous applications other than automobiles, such as for other vehicles, bicycles and accessories. In addition to being useful as an intermediate for preparing the diketopyrrolopyrrole derivatives of the formulas (I, la, and / or Ib), the hydroxymethyl pyrrolopyrrole compound of the formula (II) is useful as a stabilizer for polymers. The diketopyrrolopyrrole derivatives of the formulas (I, la, and Ib) are useful as colorants, such as pigments and dyes, for a variety of materials, in particular paints, plastics and inks and as additives that influence the rheological characteristics of a composition. of pigments. In general, the diketopyrrolopyrrole derivatives of the formulas (I, la, and Ib) with a lower degree of sulfonation are more suitable as pigments, while those with a higher degree of sulfonation are useful as colorants and additives. The following examples further illustrate the preferred embodiments of this invention. In these examples, all parts given are by weight, unless otherwise noted. All viscosity measurements are taken at room temperature.

Example 1: 500 grams of concentrated sulfuric acid (95.28%) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a drying tube, then 6.2 grams (0.206 moles) are introduced. ) of paraformaldehyde and then introduced into the sulfuric acid followed by 28.8 grams (0.1 moles) of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole (unsubstituted DPP) in small portions maintaining the temperature of the container below 30 ° C. The reaction mixture is stirred at 25 ± 2 ° C for 2.5 hours and then poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give 2.5 -di (hydroxymethyl) -3,6-diphenylpyrrolo [3,4-c] pyrrole-1,4-dione (analysis of C20H18N2O4). Examples 2-5: The bis (hydroxymethyl) DPP compounds described in Table 1 were prepared by replacing the appropriate substituted DPO with unsubstituted DPP in the process of Example 1: or Table 1 Bishydroxymethyl Derivatives DPP A1 A2 Mol. I > or Mol. Crystallized form 4-CI-phenyl 4-CI-phenyl C20H? 4CI2N2O 417 DMF-MeOH p-tolyl p-tolyl C22H20N2O 376 DMF-MeOH 4-t-butyl-t-butyl-phenyl C28H32N2O 460 DMF-MeOH phenyl b if enyl-1-yl bifenyl-1-yl C32H24N2O 500 DMF-MeOH Example 6: 250 grams of concentrated sulfuric acid (96%) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a continuous reflux condenser for drying. 14.4 grams 0.05 moles) of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole (unsubstituted DPP) are added in small portions keeping the temperature of the vessel below 25 ° C. Then 3.1 grams (0.103 moles) of paraformaldehyde are introduced and then introduced into the reaction mixture. The reaction mixture is stirred at 25 ± 2 ° C for four hours and then poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give 2.5 -di (hydroxymethyl) -3,6-diphenylpyrrolo [3,4-c] pyrrole-1,4-dione (Analysis of C20H? 6N2O4).

Example 7: 401.2 grams of concentrated sulfuric acid (96%) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a drying tube. 17.85 grams (0.05 moles) of 1,4-diketo-3,6-di (4-chlorophenyl) pyrrolo [3,4-c] pyrrole (DPP of dichloro) are added in small portions keeping the temperature of the container below 30 ° C. Then 3.1 grams (0.103 moles) of paraformaldehyde are introduced into the reaction mixture. The reaction mixture is stirred at 25 ± 2 ° C for four hours and then poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give 2.5- di (hydroxymethyl) -3,6-di (4-chlorophenyl) pyrrolo [3,4-c] pyrrole-1,4-dione (analysis of C20H14Cl2N2O4). Example 8: 422.9 grams of concentrated sulfuric acid (96%) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a drying tube. 22.0 grams (0.05 moles) of 1,4-diketo-3,6-di (biphenyl-1-yl) pyrrolo [3,4-cjpyrrole (dichlorope DPP) are added in small portions keeping the temperature of the container below 30 ° C. Then 3.1 grams (0.103 moles) of paraformaldehyde are introduced into the reaction mixture. The reaction mixture is stirred at 25 ± 2 ° C for four hours and then poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give 2.5- di (hydroxymethyl) -3,6-di (biphenyl-1-yl) pyrrolo [3,4-c] pyrrole-1,4-dione (analysis of C 32 H 24 N 2 O 4). Example 9: 250 grams of concentrated sulfuric acid (96%) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a drying tube. Quinacridone (31.2 grams, 0.1 moles) is added in small portions followed by 14.4 grams (0.05 moles) of 2 1, 4-diketo-3,6-defenilpirrolo [3,4-c] pyrrole (unsubstituted DPP) maintaining the container temperature between 40-45 ° C. After stirring for 0.5 hours, 3.1 grams (0.103 moles) of paraformaldehyde are introduced into the reaction mixture and the temperature is raised to about 50 ° C. The reaction is stirred at 45 ± 3 ° C for 1 hour and then poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give the compound of the formula wherein Ai and A2 are each phenyl and B, and B2 are quinacridinyl radicals. The product analysis for C6oH35 5NeOe »(S03H) or 5 Example 10: 250 grams of concentrated sulfuric acid (96%) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a drying tube. 14.4 grams (0.05 moles) of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole (unsubstituted DPP) were added in small portions keeping the temperature of the vessel below 40 ° C. After stirring for 0.5 hours, 3.1 grams (0.103 moles) of paraformaldehyde are introduced into the reaction mixture and the temperature is raised to about 45 ° C. The reaction is stirred at 45 ± 2 ° C for 1 hour and then poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give the compound of the formula where and B2 are quinacridinyl radicals. Product analysis for C6oH3s.sN6? 6 «(S03H) o.s Example 11: 250 grams of concentrated sulfuric acid (96%) are added to a one liter four-necked flask equipped with a stirrer, a thermometer and a condenser.

Reflux with a drying tube. 14.4 grams (0.05 moles) of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole (unsubstituted DPP) were added in small portions keeping the temperature of the vessel below 25 ° C. After stirring for 0.5 hours, 3.1 grams (0.103 moles) of paraformaldehyde are introduced into the reaction mixture and the temperature is raised to about 25 ° C. The reaction is stirred at 25 ± 2 ° C for 1 hour and then poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give the compound of the formula wherein Bi and B2 are quinacrydinyl radicals. Product analysis for C6oH36N6? 6 Example 12: 400 grams of concentrated sulfuric acid (96%) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a drying tube. 14.4 grams (0.05 moles) of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole (unsubstituted DPP) were added in small portions while maintaining the container temperature by below 25 ° C. After stirring for 0.5 hours, 3.1 grams (0.103 moles) of paraformaldehyde are introduced into the reaction mixture followed by 38. grams of 4,11-dichloroquinacridone (0.1 moles) and the temperature was kept below 45 ° C. The reaction is stirred at 45 ± 2 ° C for 2.5 hours and then poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give the compound of the formula where - and B2 are 4,11-dichloroquinacridinyl radicals. The product analysis for C6oH34Cl? 2N6? 6. Example 13: 500 grams of concentrated sulfuric acid (90%) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a drying tube. 6.2 grams (0.206 moles) of paraformaldehyde are added in small portions and then introduced into the sulfuric acid followed by 28.8 grams (0.1 moles) of 1,4-diketo-3,6-diphenylpyrrolo [3,4-c] pyrrole ( DPP not replaced) keeping the temperature of the container below 30 ° C. The reaction mixture was stirred at 25 ± 2 ° C for 2.5 hours and then it was poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized to give 2,5-di (hydroxymethyl) -3,6-dif eni I pyrrolo [3, 4-c] pyrrole-1,4-dione and the starting materials. When 85% H2SO4 replaces 90% H2SO4, a mixture containing a larger portion of the starting materials is obtained. Example 14: 250 grams of concentrated sulfuric acid (96%) and paraformaldehyde (3.3 g, 0.11 mole) are added to a one-liter four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a drying tube. . Unsubstituted DPP (14.4 g) was added; 0.05 moles) to the mixture is sulfuric acid / paraformaldehyde in small portions maintaining the temperature between 25-30 ° C. This mixture was stirred for 1 hour to ensure the complete solution. Then 200 g of sulfuric acid was added to the reaction mixture followed by unsubstituted DPP (28.8 g, 0.1 mole) in small portions, maintaining the container temperature at 32-34 ° C. The reaction mixture was then stirred at 30 ± 3 ° C for 4 hours and poured into ice water, filtered, washed with water until the filtrate was acid free, dried and pulverized. The isolated compound analyzed for Cs6H35N606 and believed to have the formula IV wherein each substituent R and Ri is hydrogen. The compounds in Table 2 are formed by replacing the appropriate pyrrolopyrrole reagents in the process of Example 14.

R Ri Forma Mol. Crist Form H Cl CseHs.CUNeOe H2S04 H t -butyl 0? Heß eO? H2S04 H 4-phenyl 0 CeoHs? NeOe H2S04 Cl H C56H3oCI2N606 H2S04 Cl Cl CseHsoCle eOe H2SO4 Cl CH3 606oH42CI2N606 H2SO4 Cl t -butyl 0 C72H66CI2N6? 6 H2SO4 Cl 4-phenyl 0 C8oHsoCI2Ne? 6 H2SO4 CH3 Cl Cs8H36CI2Ne? 6 H2SO4 CH3 CH3 C62H48N606 H2SO4 CH3 t-butyl or C74H72N606 H2SO4 CH3 4- phenyl C82H56N605 H2S04 t-butyl H C64H52N6? 6 H2S04 t-butyl Cl C64H48CI4N6Oe H2S04 t-butyl CH3 CeßHeoNßOe H2S04 t-butyl t-butyl C8oH84Ne? 6 H2S04 t-butyl 4-phenyl CßsHßß NßOß H2S04 4-phenyl H C68H44N606 H2S04 4-phenyl Cl C68H40CI4Ne? 6 H2S04 4-phenyl CH3 C72H52N606 H2S04 4-phenyl t- • butyl C84H eNe? 6 H2S04 4-phenyl 4-phenyl C92HeoNeOe H2S04 Example 15: 250 grams of concentrated sulfuric acid (96%) and formaldehyde (3.3 g, 0.11 mole) were added to a one-liter, four-necked flask equipped with a stirrer, a thermometer and a reflux condenser with a condensing tube. drying Unsubstituted DPP (14.4 g, 0.05 mole) was added to the mixture of sulfuric acid / paraformaldehyde in small portions keeping the temperature of the vessel between 30-35 ° C. This mixture was stirred for 1 hour to ensure complete solution. Then an additional 200 g of sulfuric acid was added to the reaction mixture followed by unsubstituted DPP (28.8 g, 0.1 mol) in small portions, maintaining the temperature of the vessel at 3842 ° C. This reaction mixture is then stirred at 40 ± 3 ° C for 4 hours and poured into ice water, filtered, washed with water until the filtrate is acid free, dried and pulverized. The isolated compound analyzed for C56H36N6Δ6"(S ?3H) or s- The sulfonated derivatives of the compounds of Table 2 are prepared by substituting the appropriate pyrrolopyrrole reagents in the process of Example 15. Example 16: Bishydroxymethyl DPP ( 17.4 g, 0.05 moles), aniline (9.3 g, 0.1 moles) and DMF (100 ml) were added to a one-liter four-necked flask, equipped with a stirrer, a thermometer, and a reflux condenser with a drying tube. The mixture was stirred at 100 ° C for 4 hours, then diluted with water, filtered, washed with water, dried and pulverized to give 2,5-di (anilinomethyl) -3,6-diphenyl pyrrolo [3 , 4-c] pyrrole-1,4-dione (bisanilinomethyl DPP). Example 17: Bishydroxymethyl DPP (17.4 g, 0.05 mole), a catalytic amount of paratuluenesulfonic acid and methane (100 ml) were added to a one-liter four-necked flask, equipped with a stirrer, a thermometer, and a condenser. Reflux with a drying tube. The mixture was stirred at 100 ° C for 4 hours, then diluted with water, filtered, washed with water, dried and pulverized to give 2,5-di (methoxymethyl) -3,6-diphenyl pyrrolo [3 , 4-c] pyrrole-1,4-dione (bisanilinomethyl DPP). Example 18: DPP of bishydroxymethyl-di-t-butyl (23.0 g, 0.05 mole), a catalytic amount of paratoluenesulfonic acid and methane (100 ml) were added to a four-necked flask of a liter, equipped with a stirrer, a thermometer, and a reflux condenser with a drying tube. The mixture was stirred at reflux for 4 hours, then diluted with water, filtered, washed with water, dried and pulverized to give 2,5-di (methoxymethyl) -3,6-diphenyl pyrrolo [3,4 -c] pyrrole-1,4-dione (DPP of bisanilinomethyl-di-t-butyl). Examples 19-26: The following compounds, wherein Ai, A2 and R are defined according to formulas (la) and (III) are prepared according to the procedures of Examples 9-12 substituting the appropriate DPP and compounds of Quinacridone: Example 27: A pigment composition was prepared by adding an agent to treat a surface consisting of the pyrrolopyrrole derivative of the formula (la), alone or combined with a second rheology enhancing agent to an aqueous suspension of the pigment, filtering and washing to produce the composition of the pigment. The viscosity of a dispersion of the pigment composition in a commercial paint formulation dissolved in a high solids solvent was measured at 50 rpm.

QMA = aluminum salt of quinacridone sulphonic acid, PMQA = pyrazolylmethylquinacridone 1 = a solution of ternary solid of DPP of dichloro / DPP / 2,9-dichloro QA (48/32/20) 2 = solution of binary solid of DPP of dichloro / 2,9-dichloro QA (60/40) 3 = 1,4-diketo-3,6-di (biphenyl-1-yl) pyrrolopyrrole Example 28: A solid solution of dichloro / dichloroquinacridone DPP (40/60 ) was prepared by grinding a mixture of two individual components on a roller for 24 hours and the ground powder was stirred with 2% sulfuric acid for 2 hours at 90 ° C and then filtered and the resulting pigment slurry was washed. The resulting pressed cake was remelted in water and combined with the rheology enhancing agent (s) specified in the following table, filtered, washed, dried and pulverized to a treated pigment. A pigment dispersion containing 10% pigment and 30% solids in a pigment / binder ratio of 0.5 was prepared by combining the pigment treated with acrylourethane resin, dispersant resin and solvent and grinding with grinding medium for 64 hours. The viscosity of Brookfield of the resulting pigment dispersion was reported in the following table.

Example 29: Automotive finishes were obtained by spraying aluminum panels with a metallic paint or mica formulation prepared by conventional methods and pigmented with the pigment compositions described above. The coatings exhibit intense, attractive colors, with excellent high brightness of two tones and image distinction. Example 30: A solution pigment of organic ternary solids which are composed of non-substituted dichloro DPP / DPP / 1,9-dichloroquinacridone (48% / 32% / 20%) is combined with a rheology enhancing agent composed of 4% salt of aluminum quinacridone monosulfonic acid (QMA) and 4% of the pyrrolopyrrole derivative of Example 14 by adding the rheology enhancing agent to an aqueous suspension of the pigment, filtering and washing to give the pigment composition. The rheology profiles of pigment dispersions in a paint formulation that is dissolved in commercial solvent with high solids content containing approximately 12% by weight of the pigment in a pigment-to-binder ratio of 0.5% are described in Table 3. Table 3 MILL BASE VISCOSITY (BROOKFIELD) Painting system: BC / DC; % Pigment: 12.0%; P / B = 0.5 Sample ID rheology enhancing agent 50 RPM 30a Not treated 3660 30b% QMA + 4% of Example 14 R = 1 = H 828 Example 31: A colored di (t-butylphenyl) -DPP pigment was combined orange with a rheology enhancing agent described according to the formula (IV) given in example 14. The rheology profiles of the pigment dispersions in a commercial paint formulation that is dissolved in a high solids solvent containing approximately 16% by weight of the pigment in a pigment-to-binder ratio of 0.5% measured after 4 hours of friction grind are described in Table 4.

Table 4 Mill Base Viscosity (Brookfield) The rheology enhancement of examples 31c and 31d, in addition to the rheology improvements, improves the color saturation of the pigment when sprayed onto a panel as part of a conventional basecoat / clearcoat automotive finish. Similarly, improved color is observed when using a different eye or orange pigment, for example quinacridone, in place of di (t-butylphenyl) -DPP. Example 32: An orange-colored di (t-butylphenyl) -DPP pigment was combined with the mixture of rheology enhancing agents described in Table 5 with R and R-de being described according to formula (IV) given in example 14 and PYMQ being pyrazolylmethylquinacridone. The rheology profiles of pigment dispersions in a commercial paint formulation that is dissolved in a high solids solvent containing approximately 16% by weight of the pigment in a ratio of 0.5% pigment to binder measured after 4 hours of friction grinding as described in Table 5. Table 5 Mill Base Viscosity (Brookfield)

Claims (12)

1. CLAIMS 1. A process for the preparation of a diketopyrrolopyrrole derivative of the formula (I) wherein Ai and A2 are identical or different aryl radicals and Bi and B2 are identical or different organic radicals; which contain diketopyrrolopyrol derivatives of 0 to 6 moles of -S03M per mole of the diketopyrrolopyrrole derivative; wherein M is hydrogen or a metal or ammonium cation, which process comprises a reaction wherein a 1,4-diketo-3,6-diarylpyrrolopyrrole of the formula is reacted in a first step with formaldehyde or paraformaldehyde to give a sulfonated or non-sulphonated intermediate of the formula which reacts in a second step with a precursor of the organic radicals, Bi and B2 to give the diketopyrrolopyrrole derivative of the formula (I).
2. 2. A process for the preparation of a diketopyrrolopyrrole derivative of the formula 81) wherein a 1,4-diketo-3,6-diarylpyrrolopyrrole of the formula (II) is reacted with a precursor of the organic radicals, Bi and B2.
3. 3. A process of claim 1 or 2, wherein the precursor of the organic radicals, Bi and B2, is a 1,4-diketo-3,6-diarylpyrrolo [3,4-c] pyrrole or a quinacridone.
4. 4. A compound of the formula containing 0 to 6 moles of -S03M per mole of the compound, wherein Ai and A2 are identical or different aryl radicals and M is hydrogen or a metal or ammonium cation.
5. 5. A process for preparing a compound of the formula containing from 0 to 6 moles of -S03M per mole of the compound, wherein Ai and A2 are identical or different aryl radicals and M is hydrogen or a metal or ammonium cation; said process comprises reacting a 1,4-diketo-3,6-diarylpyrrolopyrrole of the formula with formaldehyde or paraformaldehyde.
6. 6. A diketopyrrolopyrrole derivative of the formula (la) QA "-CH: N N CH-1 QA (| a) O wherein Ai and A2 are identical or different aryl radicals, having the meaning given above, and QA is a quinacridone radical; said pyrrolopyrrole derivative is substituted from 0 to 6 moles of - S03M per mole of the pyrrolopyrrole derivative; wherein M is hydrogen or a metal or ammonium cation.
7. 7. A pyrrolopyrrole derivative of claim 6, wherein each QA is a quinacridone radical of the formula (III) wherein each R is independently hydrogen, halogen, carboxyl, unsubstituted d-C6 alkyl, C? -C6 alkyl which is substituted by a halogen, unsubstituted C? -C6 alkoxy, or C? -C6 alkoxy which it is replaced by a halogen.
8. 8. A pyrrolopyrrole derivative of the formula (Ib) wherein Ai and A2 are identical or different aryl radicals and each DPP is a diaryldicetopyrrolopyrrole radical; said diketopyrrolopyrrole derivative is substituted by from 0 to 6 moles of -S03M per mole of the pyrrolopyrrole derivative; wherein M is hydrogen or a metal or ammonium cation.
9. 9. A pigment composition which comprises an organic pigment and a pyrrolopyrrole derivative of the formulas (I, la, Ib) according to claims 1, 6, 7 or 8.
10. 10. A method for reducing the viscosity of a dispersion of an organic pigment in an organic compound of high molecular weight, which comprises incorporating an effective viscosity reducing amount of a pyrrolopyrrole derivative of the formulas (I, la, Ib) in accordance with Claims 1, 6, 7 or 8, in the dispersion.
11. 11. A method for preparing a basecoat / clearcoat finish, which comprises the step of applying a dispersion comprising an organic pigment and an effective viscosity reducing amount of a pyrrolopyrrole derivative of the formulas (I, Ib) according to claims 1, 6, 7, or 8, in an organic compound of high molecular weight for a substrate.
12. 12. A method for preparing a basecoat / clearcoat finish, which comprises the step of applying a dispersion comprising an effective viscosity reducing and saturating amount of a pyrrolopyrrole derivative of the formulas Ib in accordance with claim 8 in a high molecular weight organic compound for a substrate.