AMINO-IMINOISOINDOLENINE BENZENE SULFONATE, AND PROCESS FOR THE PREPARATION OF NITRATE AND BENZENE SULFONATE SALTS OF AMINO-AMINOISOINDOLENINE DERIVATIVES

Abstract: A process for the preparation of isoindolenine salts of formula (I), wherein R1, R2, R3 and R4 are each independently of one another hydrogen, halogen, C1-C4-alkyl, C1-C4alkoxy, phenoxy, -NHR5 or -N(R5)2, R5 is C1-C4alkyl, and X is NO3, or (1) by reacting 1 mol of a compound of formula (II), wherein Y is O or NH, with 3 to 10 mol of urea and a) if X is NO3, with 1 to 3 mol of a mixture consisting of ammonium nitrate and 5 to 90 mol%, based on the ammonium nitrate, of an ammonium salt of formula (III): NH4Z, wherein Z is 1/2 SO4 or Q SO3, and Q is C1-C24alkyl, unsubstituted or C1-C4alkyl-substituted phenyl or naphthyl, or b) if X is (2) either with 2 to 4 mol of ammonium benzenesulfonate or 1 to 2 mol of a mixture consisting of ammonium benzenesulfonate and 5 to 50 mol% of ammonium nitrate, based on the ammonium benzenesulfonate, in the temperature range from 150 to 220 DEG C and subsequently processing the resultant product by customary methods. This process substantially improves the stirrability of the reaction mixture at the end of the reaction. Additionally, the isoindolenine salts of formula (I), wherein X<-> is benzene sulfonate.

Description: AMINO-IMINOISOINDOLENINE BENZENE SULFONATE, AND PROCESS FOR THE PREPARAΗON OF NITRATE AND BENZENE SULFONATE SALTS OF AMINO-AMINOISOINDOLENINE DERIVATIVES The present invention relates to a process for the preparation of isoindolenine salts, which is characterised by the use of certain ammonium salts or ammonium salt mixtures. It is known that isoindolenine salts are produced from phthalic acid derivatives, urea and corresponding salts as precursors to different products, for example phthalocyanine, isoindolino- ne and isoindoline pigments. The chemical fundamentals of these processes are disclosed, inter alia, in US patent 2 727 043. There, phthalic acid anhydride or phthalimide is reacted at elevated temperatures with urea and, as salt, preferably with ammonium nitrate, with or without solvents in the presence of a small amount of ammonium molybdate as catalyst. Said US patent also describes the use of other salts, for example p-toluenesulfonic acid, ammonium methanesulfonate, ammonium chloride, sodium naphthalene- 1-sulfonate and a mixture of ammonium nitrate and diammonium phosphate, which, however, afford only low yields. DD patent specification 207908 discloses a similar method, in which the crude materials, phthalic acid anhydride, urea, ammonium nitrate and catalytic amounts of ammonium molybdate, are reacted, with continuous stirring, at 140 to 220°C in the melt without the addition of solvents, the melt being mixed at a certain viscosity with water so that the product can be separated using a centrifuge. So far, only those processes have been of commercial importance which use ammonium nitrate. These processes all use comparatively high concentrations of ammonium nitrate and comparatively little urea. The thermal decomposition potential of such reaction mixtures is above 1000 J/g. Towards the end of the reaction their viscosity increases sharply, resulting in substantial additional technical expenditure when the reaction is carried out on an industrial scale. As is known, there is also a high explosion risk involved when working with high nitrate concentrations at a high temperature range, in particular in the presence of solvents or if there is a strong frictional resistance. It has now been found that carrying out the reaction with certain ammonium salts, i.e. either with a mixture of ammonium nitrate and ammonium sulfate, or with a mixture of ammonium nitrate and ammonium sulfonates, or with a high excess of ammonium benzenesulfonate on its own, or with a low excess of ammonium benzenesulfonate together with a small amount of ammonium nitrate (i.e. adding a markedly smaller amount of ammonium nitrate, or even none at all) while simultaneously increasing the concentration of urea, surprisingly achieves a sub- stantial decrease of the exothermal decomposition potential (from about 1200 J/g to about 600 J/g with nitrate or to about 0 J/g without nitrate) and of the solidification temperature of the reaction mixture (from about 160° to about 100°C), resulting in a substantially improved stirrability of the reaction mixture at the end of the reaction. This in turn results in a crucial and highly welcome enhanced operational safety which even makes a small reduction in yield readily acceptable. Accordingly, this invention relates to a process for the preparation of isoindolenine salts of formula wherein R 1 ( R 2 , R 3 and R 4 are each independently of one another hydrogen, halogen, C^^- alkyl, C^alkoxy, phenoxy, -NHR 5 or -N(R 5 ) 2 , R 5 is C 1 -C 4 alkyl, and X is NO 3 or by reacting 1 mol of a compound of formula wherein Y is 0 or NH, with 3 to 10 mol of urea and, a) if X is NO 3 , with 1 to 3 mol of a mixture consisting of ammonium nitrate and 5 to 90 mol%, based on the ammonium nitrate, of an ammonium salt of formula NH 4 Z (III), wherein Z is 1/2 SO 4 or Q SO 3 , and Q is C 1 -C 24 alkyl, unsubstituted or C r C 4 alkyl-substituted phenyl or naphthyl, or, b) if X is either with 2 to 4 mol of ammonium benzenesulfonate or 1 to 2 mol of a mixture consisting of ammonium benzenesulfonate and 5 to 50 mol% of ammonium nitrate, based on the ammonium benzenesulfonate, in the temperature range from 150 to 220°C and subsequently processing the resultant product by customary methods. The isoindolenine salts of formula I can also be obtained in another tautomeric form. Any substituents defined as halogen are, for example, iodo, bromo or, preferably, chloro. C 1 -C 4 Alkyl is typically methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl or tert-butyl, and C r C 4 aikoxy is typically methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy or tertbutoxy. Q defined as C^C^alkyl is, for example, methyl, ethyl, n-propyl, n-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, tetradecyl, hexadecyl, octadecyl, eicosyl, heneicosyl, docosyl or tetra- cosyl. R . > R 2 , R 3 and R 4 are each independently of one another preferably chloro or, in particular, hydrogen. Y is preferably NH. Z is preferably 1/2 SO 4 or Q SO 3 , wherein Q is C C^alkyl or unsubstituted phenyl or naphthyl. However, Z is particularly preferably benzenesulfonate or, more preferably, sulfate. The reaction is carried out by processes known per se. It is convenient to add one of the catalysts customarily used for analogous reactions, for example molybdate, vanadate, chromate, titanate or tungstate, in particular corresponding potassium salts, sodium salts or, preferably, ammonium salts in an amount of 0.0001 to 0.001 , preferably of 0.0002 to 0.0008 mol, per 1 mol of starting compound of formula II. Ammonium molybdate is particularly preferred. If desired, it is also possible to use an inert organic solvent, but the reaction can also be carried out very well without the addition of a solvent. The addition of a solvent has the advantage of preventing foam formation and additionally improving stirrability a little. Suitable solvents are, for example, biphenyl, diphenyl ether, mesitylene, anisole, phenetole, dichloro- and trichlorobenzene, nitrobenzene and mixtures thereof, conveniently in an amount of 0.5 to 5, preferably of 0.7 to 3, parts by weight to 1 part by weight of the starting compound of formula II. The reaction is preferably carried out in the temperature range from 160 to 180°C without solvent or, preferably, with nitrobenzene or, more preferably, with diphyl (mixture of biphenyl and diphenyl ether, also obtainable as Dowtherm A). Per 1 mol of the compound of formula II it is preferred to use 4 to 7 mol of urea and, in procedure a), 1.5 to 2 mol of a mixture consisting of ammonium nitrate and 10 to 50 mol%, preferably 15 to 25 mol%, of the ammonium salt of formula III, based on ammonium nitrate, and, in procedure b), 2.5 to 3.5 mol of ammonium benzenesulfonate or 1 to 2 mol of a mixture consisting of ammonium benzenesulfonate and 15 to 30 mol% of ammonium nitrate, based on ammonium benzenesulfonate. For processing, the reaction mixture is diluted with water, low alcohols, such as methanol or ethanol, diols or polyols, such as glycol or glycerol, ethers, such as tetrahydrofuran, dioxane or dimethoxyethane, and the end product is then collected by filtration and the residue is washed with the same solvent, which is preferably water or, more preferably, methanol. Isoindolenine salts of formula I, wherein R 1 ( R 2 , R 3 and R 4 have the meaning cited above and x is 503 are novel and are therefore another object of this application. R,, R 2 , R 3 and R 4 have the preferred meanings cited above. As mentioned at the outset, the isoindolenine salts obtained according to this invention are used as starting products for the preparation of different products, inter alia preferably of isoindoline, isoindolinone and phthalocyanine pigments. The invention is illustrated by the following Examples. Example 1 : A mixture consisting of 125 g diphyl (26.5 % of biphenyl/73.5 % of diphenyl ether, obtainable as Dowtherm A), 33.4 g (0.25 mol) of ammonium sulfate and 0.5 g (0.0004 mol) of ammonium molybdate is heated, with stirring, to 140°C and is then charged with 148.6 g (1 mol) of phthalimide. Heating is continued and at 150-155°C the mixture is charged with 360.6 g (6 mol) of urea in 8 portions, gas starting to evolve already at this point (NH 3 + CO 2 ). The mixture is then charged with 105.1 g (1.3 mol) of ammonium nitrate at 140-150°C and is heated to the reaction temperature (160-165°C) and allowed to react for 4 hours at this temperature. The resultant greenish-yellow crystal slurry is cooled to 105-100°C and then 325 g of methanol are added dropwise and the mixture is stirred at reflux for 30 min and is then cooled to room temperature and filtered. The residue is washed with 300 g of methanol and dried at 80°C under vacuum, giving 211.3 g (85.9 % of theory) of the nitrate of formula as a pale yellow gritty powder. Example 2: The procedure of Example 1 is repeated, with the following exceptions: using 150 g of nitrobenzene instead of 125 g of diphyl using 330.6 g (5.5 mol) instead of 360.6 g of urea using 88.8 g (1.1 mol) instead of 105.1 g of ammonium nitrate, and obtaining 215.1 g of the same product as in Example 1. Example 3: A mixture consisting of 148.6 g (1 mol) of phthalic acid anhydride, 420.7 g (7 mol) of urea, 0.5 g (0.0004 mol) of ammonium molybdate, 66.7 g (0.5 mol) of ammonium sulfate and 88.8 g (1.1 mol) of ammonium nitrate is placed in a vessel and melted. The suspension becomes stirrable from about 71 °C. The foamy viscous suspension is then heated to the reaction temperature (165-170°C) and is allowed to react, with stirring, for 4 hours at this temperature, gas starting to evolve from about 143°C (NH 3 + CO 2 ). After cooling the whitish- yellow suspension to 100°C, it is charged with 636 g of methanol, stirred for 1 hour at reflux and is then cooled to room temperature and filtered. The residue is washed with 557 g of methanol and dried at 80°C under vacuum, giving 208.8 g (73.1 % of theory) of the nitrate of formula IV (cf Example 1) as a pale yellow gritty powder. Example 4: 0.8 g (0.0006 mol) of ammonium molybdate and 148.6 g (1 mol) of phthalic acid anhydride are added, with stirring, to 338 g of o-dichlorobenzene which is heated to 140°C. Heating is continued and at a temperature between 155 and 160°C the mixture is charged with 420.7 g (7 mol) of urea in 7 portions, gas starting to evolve already at this point (NH 3 + COa). 175.2 g (1 mol) of ammonium benzenesulfonate are then added in 2 portions. The greenish-brown suspension is heated to the reaction temperature (165-167°C) and is stirred for 9 to 10 hours at this temperature. The mixture is then cooled to 107°C and charged with 650 g of methanol, stirred for 1 hour at reflux, cooled to room temperature and filtered. The residue is washed with 400 g of methanol and dried at 80°C under vacuum, giving 278.3 g (80.1 % of theory) of the benzenesulfonate of formula as pale green needles. [Example 5: A mixture consisting of 148.6 g (1 mol) of phthalimide, 240.4 g (4 mol) of urea, 87.6 g (0.5 mol) of ammonium benzenesulfonate and 88.8 g (1.1 mol) of ammonium nitrate is placed in a vessel and melted. The suspension becomes stirrable from about 82°C and is then heated to the reaction temperature (170°C), gas starting to evolve from about 160°C (NH 3 + CO 2 ). This reaction is markedly slower without the ammonium molybdate catalyst, only 25 % of phthalimide being reacted in 6 Vfe hours. If, after a 25 % reaction, 0.3 g (0.0002 mol) of ammonium molybdate are added, then the remaining 75 % can be reacted in another 9 hours at 170-175°C. The green viscous suspension is cooled to 100°C, charged with 318 g of methanol, stirred for 1 hour at reflux and is then cooled to room temperature and filtered. The residue is washed with 795 g of methanol and dried at 80°C under vacuum, giving 192.6 g (78.1 % of theory) of the compound of formula IV (cf Example 1). Example 6: 148.6 g (1 mol) of phthalimide, 240.4 g (4 mol) of urea, 175.2 g (1 mol) of ammonium benzenesulfonate, 0.6 g (0.0005 mol) of ammonium molybdate and 88.8 g (1.1 mol) of ammonium nitrate are placed in a vessel and melted. The suspension becomes stirrable from about 80°C. With stirring, the suspension is heated to the reaction temperature (165-170°C), gas starting to evolve from about 151 °C (NH 3 + CO 2 ). After allowing the reaction mixture to react, with stirring, for another 6 1/2 hours at 165-170°C, the blueish-white viscous suspension is cooled to 100°C, charged with 318 g of methanol, stirred for 1 hour at reflux and is then cooled to room temperature and filtered. The residue is washed with 795 g of methanol and dried at 80°C under vacuum, giving 218.4 g (88.9 % of theory) of the nitrate salt of formula IV (cf Example 1). Example 7: 148.6 g (1 mol) of phthalimide, 240.4 g (4 mol) of urea, 112.6 g (0.5 mol) of ammonium naphthalene-2-sulfonate, 88.8 g (1.1 mol) of ammonium nitrate and 0.6 g (0.0005 mol) of ammonium molybdate are suspended, with stirring, in 480 g of nitrobenzene. This suspension is heated to the reaction temperature (170-175°C), gas starting to evolve from about 155°C (NH 3 + COa). Stirring is continued for 5 hours at 170-175°C and the orange suspension is then cooled to 100°C, charged with 955 g of methanol, stirred for 1 hour at reflux and cooled to room temperature and filtered. The residue is washed with 795 g of methanol and dried at 80°C under vacuum, giving 176.2 g (78.3 % of theory) of the nitrate salt of formula IV (cf Example 1). Example 8: The procedure of Example 7 is repeated, with the sole exception that ammonium naphthalene-2-sulfonate is replaced with the equivalent amount of ammonium toluenesulfo- nate, giving 155.8 g (65.5 % of theory) of the same product as in Example 7. Example 9: The procedure of Example 7 is repeated, with the sole exception of using 113.2 g (1 mol) of ammonium methanesulfonate instead of 112.6 g of ammonium naphthalene-2- sulfonate, and 600 g instead of 480 g of nitrobenzene, giving 172.6 g of the same product as in Example 7. Example 10: 26.7 g (0.2 mol) of ammonium sulfate in 50 g of nitrobenzene are placed in a vessel. With stirring, 420.7 g (7 mol) of urea are added in portions at an external temperature of 150°C. With continuous stirring and at an internal temperature of 135-140°C, first 148.6 g (1 mol) of phthalic acid anhydride are added in portions and then 88.8 g (1.1 mol) ammonium nitrate and 0.5 g (0.0004 mol) ammonium molybdate. Subsequently, the suspension is heated to the reaction temperature (165-170°C), gas starting to evolve at about 146°C (NH 3 + COz). The reaction mixture is allowed to react for 3 1/2 hours at 165-170°C and is then cooled to 100°C and charged with 300 g of water and 150 g of ice over 20 minutes. The two- phase suspension is filtered immediately and the residue is washed with 200 g of methanol and dried at 80°C under vacuum, giving 149.3 g (70.4 % of theory) of the nitrate of formula IV (cf Example 1). Example 11 : A mixture consisting of 148.6 g (1 mol) of phthalimide, 360.6 g (6 mol) of urea, 66.7 g (0.5 mol) of ammonium sulfate, 88.8 g (1.1 mol) of ammonium nitrate and 0.5 g (0.0004 mol) of ammonium molybdate is placed in a vessel and melted. The suspension becomes stirrable from about 74°C. With stirring, the suspension is then heated to the reaction temperature (160-165°C), gas starting to evolve from about 125°C (NH 3 + COz). After stirring for 4 1/2 hours at 160-165°C, the yellow viscous suspension is cooled to 100°C and 500 g of water are added over 15 minutes and the mixture is stirred for 30 minutes and filtered. The residue is washed with 1 I of water and dried at 80°C under vacuum, giving 154 g (72.7 % of theory) of the nitrate of formula IV (cf Example 1).

Claims: What is claimed is 1. A process for the preparation of isoindolenine salts of formula wherein R,, R 2 , R 3 and R 4 are each independently of one another hydrogen, halogen, 0,-0, alkyl, C r C 4 alkoxy, phenoxy, -NHR 5 or -N(R 5 ) 2 , R s is C Calkyl, and X is NO 3 or by reacting 1 mol of a compound of formula wherein Y is 0 or NH, with 3 to 10 mol of urea and, a) if X is NO 3 , with 1 to 3 mol of a mixture consisting of ammonium nitrate and 5 to 90 mol%, based on the ammonium nitrate, of an ammonium salt of formula NH 4 Z (III), wherein Z is 1/2 SO 4 or Q SO 3) and Q is C^C^aUcy!, unsubstituted or CrC^alkyl-substituted phenyl or naphthyl, or, b) if X is either with 2 to 4 mol of ammonium benzenesulfonate or 1 to 2 mol of a mixture consisting of ammonium benzenesulfonate and 5 to 50 mol% of ammonium nitrate, based on the ammonium benzenesulfonate, in the temperature range from 150 to 220°C and subsequently processing the resultant product by customary methods. 2. A process according to claim 1 , wherein R 1 f R 2 , R 3 and R 4 in formulae I and II are each independently of one another hydrogen or chloro. 3. A process according to claim 1 , wherein Y in formula II is NH. 4. A process according to claim 1 , which comprises using 4 to 7 mol of urea per 1 mol of the compound of formula II. 5. A process according to claim 1 , procedure a), which comprises using 1.5 to 2 mol of a mixture consisting of ammonium nitrate and 10 to 50 mol% of the ammonium salt of formula III, based on the ammonium nitrate. 6. A process according to claim 5, wherein, in the ammonium salt of formula III, Z is 1/2 SO 4 or Q SO 3 , wherein Q is C.-C 12 alkyl or unsubstituted phenyl or naphthyl. 7. A process according to claim 6, wherein Z is sulfate or benzenesulfonate. 8. A process according to claim 1 , procedure b), which comprises using 2.5 to 3.5 mol of ammonium benzenesulfonate or 1 to 2 mol of a mixture consisting of ammonium benzenesulfonate and 15 to 30 mol% of ammonium nitrate, based on the ammonium benzenesulfonate. 9. A process according to claim 1 , which comprises using 0.0001 to 0.001 mol of a catalyst per 1 mol of the compound of formula II. 10. A process according to claim 9, wherein the catalyst used is 0.0002 to 0.0008 mol of the ammonium, potassium or sodium salt of molybdate, vanadate, chromate, titanate or tungstate. 11. A process according to claim 10, wherein ammonium molybdate is used. 12. A process according to claim 1 , which comprises adding an inert organic solvent or a mixture of such solvents. 13. A process according to claim 12, wherein the solvent is biphenyl, diphenyl ether, mesi- tylene, anisole, phenetole, dichlorobenzene, trichlorobenzene, nitrobenzene, or a mixture thereof. 14. A process according to claim 13, which comprises using 0.5 to 5 parts by weight of solvent per 1 part by weight of the starting compound of formula II. 15. A process according to claim 14, wherein the solvent is nitrobenzene or diphyl. 16. A process according to claim 1 , wherein the reaction is carried out without the addition of a solvent. 17. A process according to claim 1 , which comprises carrying out the reaction in the temperature range from 100 to 180°C. 18. A process according to claim 1 , wherein processing is carried out by diluting the reaction mixture with water, low alcohol, diol or polyol or ether and then filtering and washing the residue with the same solvent. 19. A process according to claim 18, wherein the reaction mixture is diluted with water or methanol. 20. A compound of formula wherein R 1t R 2) R 3 and R 4 are each independently of one another hydrogen, halogen, C,-C 4 - alkyl, C^dalkoxy, phenoxy, -NHR 5 or -N(R 5 ) 2 , R 5 is C 1 -C 4 alkyl, and X is

Inventors: BREITSCHUH RICHARD, DALLE SASSE DANIELA, BREITSCHUH, RICHARD, DALLE SASSE, DANIELA
Applicants: CIBA GEIGY AG, CIBA SPECIALTY CHEMICALS HOLDING INC.
Application year: 1998
Main classification: C07D209
IPC codes: C07D209