DE2452330A1 - Pure cationic methine dyes prepn. - from 3,3-dialkyl 2-methylene indoline aldehydes - Google Patents

Abstract

Pure cationic dyes of formula: (in which A is alkyl; A' is opt. substd. alkyl or aralkyl; A2 is H or together with the N atom, a condensed 5- or 6-member ring; A- is an anion, and rings B and E may contain further substits. are prepd. by condnsn. of aldehydes of formula: aliphatic or aromatic carboxylic or sulphonic acid and are organic solvent at 0-50 degrees (20-40 degrees)C. Used for dyeing or printing of anionic-modified fibres e.g. polyacrylonitrile or polyester. The dyes are obtd. in excellent yield and very high purity. The usual red by-products and amine-oxidn. products, which are difficult and tedious to remove from the dyes, remain wholly in soln.

Description

Process for the preparation of pure cationic dyes The invention relates to a process for the preparation of dyes of the formula I. in which the radicals A are identical or different alkyl radicals, A1 optionally substituted alkyl or aralkyl, A2 is hydrogen or, together with the nitrogen, an optionally substituted 5- or 6-ring fused to the phenyl ring in the o-position, and A, rings B and E can also carry further substituents by condensation of aldehydes of the formula II with amines of the formula III in the presence of acid and solvent, which is characterized in that an aliphatic or aromatic carboxylic or sulfonic acid is used as the acid and an organic solvent is used and that the condensation is carried out at temperatures between approximately 0 and 50, preferably 20 and 40 ° C .

Alkyl residues A are e.g. ethyl, propyl, butyl, two residues A together also pentamethylene and preferably methyl.

Residues A1 are, for example, alkyl with 1 to 4 carbon atoms, ß-hydroxyethyl or -propyl, ß-chloro- or ß-bromoethyl or -propyl, ß-cyanoethyl or benzyl.

Rings containing A2 are for example: 2,3-dihydroindole, 2,3-dihydro-2-methylindole, 2,3-dihydro-2-phenylindole, 2,3-dihydro-2,3,3-trimethylindole, hexahydrocarbocazole, 1,2,3,4-tetrahydro-6-methoxyquinoline and 1,2,3,4-tetrahydro-4-methylquinoxaline.

As substituents for the ring B are e.g. chlorine, bromine, methoxy, ethoxy, Methyl, methyl, benzyl or C1 to C4-alkoxycarbonyl and for the ring E chlorine, bromine, To name methoxy, ethoxy, methyl or ethyl.

The new process is particularly suitable for the preparation of dyes of the formula Ia or concentrated dye solutions of the dyes of the formula Ia in which R1 is methyl, ethyl or benzyl, R2 is hydrogen or, together with the nitrogen and the optionally substituted phenyl radical, a 5- or 6-membered ring with one or two heteroatoms on the another 6-membered ring Carbocycle can be condensed, R4³ hydrogen, chlorine, bromine, methyl, ethyl, methoxy or ethoxy, R4 hydrogen, chlorine, bromine, methoxy or ethoxy, Y hydrogen, chlorine, methoxy, ethoxy, methoxycarbonyl, ethoxy-.carbonyl or benzyl and A9 mean an anion.

Preferred radicals are: for Rl: methyl, for R) hydrogen, chlorine, Methyl, methoxy, for R: hydrogen, methoxy, for Y: hydrogen, chlorine, methoxy.

Preferred fused-on heterocycles are: 2,5-dihydro-2-methyl-indole, Hexahydrocarbazole, 1,2,5,4-tetrahydre-6-methoxyquinoline and 1,2,), 4-tetrahydro-4-methylquinoxaline.

Aliphatic and aromatic carboxylic and sulfonic acids that act as condensing agents are for example: propionic acid, butyric acid, chloroacetic acid, dichloroacetic acid, 5-chloropropionic acid, lactic acid, glycolic acid, diglycolic acid, pyruvic acid, Malic acid, oxalic acid, malonic acid, tartaric acid, citric acid, phenylacetic acid or Benzoic acid and especially acetic acid or formic acid.

Examples of sulfonic acids are benzenesulfonic acid or p-toluenesulfonic acid or methanesulfonic acid.

Organic solvents suitable for the new process are e.g. aliphatic and aromatic chlorinated hydrocarbons, aromatic hydrocarbons, aliphatic and cycloaliphatic ketones, cycloaliphatic ethers, aliphatic and cycloaliphatic esters, alkyl glycols, glycol acetates, alkyl diglycols, glycols, Diglycols and monohydric alcohols with 1 to 6 carbon atoms. The solvents should be chemically inert towards the reactants and the reaction products.

Examples of solvents that may be mentioned in detail are: chloroform, Perchlorethylene, benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene, acetone, methyl ethyl ketone, Cyclohexanone, dioxane, tetrahydrofuran, glycol acetate, butyrolactone, methyl glycol, Ethyl glycol, methyl diglycol, ethyl diglycol, ethylene glycol, propylene glycol, diglycol, Dipropylene glycol, methanol, methanol, l-propanol, 2-propanol, l-butanol, 2-butanol, Isobutanol, 1-pentanol, 2-pentanol and 2-hexanol.

It is preferred to use methanol, ethanol, 1-propanol, 2-propanol and isobutanol.

When preparing concentrated dye solutions are particularly suitable Ethylene glycol, propylene glycol, methyl glycol, ethyl glycol, diglycol, dipropylene glycol, Butyrolactone, glycol mono-diacetate as solvents.

Appropriately, the new process is carried out so that one the aldehyde of the formula II and the amine of the formula III in the organic solvent dissolves or suspends at 15 to 250C, if necessary impurities by filtration separates and then adds the organic acid. After about 5 to 70 minutes at The condensation has ended at 10 to 400C. Since the dyes in the reaction medium are mostly have excellent solubility, it is necessary for the production of powder goods, to precipitate the dye out of solution. This can be done, for example, by adding a mineral acid such as hydrochloric acid, sulfuric acid or phosphoric acid or e.g. zinc chloride happen. At the same time a purification is connected with the precipitation, since the Impurities remain in solution. However, the reaction solutions can also be used directly can be used, optionally after a filtration and the addition of further solvents.

The aldehyde of the formula II and the amine are advantageously the Formula III used in approximately equimolar amounts, if desired, but one can the reactants can also be used in excess. Per mole of dye the Formula I are 1 to 4 moles, preferably 1 to 2 moles, of organic acid for condensation Buzcht, 1 to 2 moles, preferably 1 mole, for example of the mineral acid, are used for precipitation.

The amount of solvent in the condensation varies depending on the solubility the reactant.

A weight ratio of solvent to reactant is preferred (Aldehyde and amine) from 1: 1 to 5: 1 are used.

Particularly good results are obtained with 1.5 to 2.5 parts by weight of solvent achieved per part by weight of the reactants.

Small amounts of water, e.g. in the solvents, the reactants or acids have no effect on the quality of the process products.

The dyes of the formula I are obtained by the new process in excellent yield and after isolation by precipitation from the reaction solution in very high purity. The aldehydes are usually formed during the condensation and amines of formula II and III red by-products and continue to be by the Amines Aminooxidationprodukte introduced in the known processes only through complex operations and even then mostly only partially removed are.

With the new process, these impurities remain completely in solution.

From DT-OS 2 o54 564 a method is known in which instead of organic acid phosphoric acid is used. Opposite this procedure has the inventive method has the great advantage that the reaction takes place at room temperature can be made; the low reaction temperature is in view of the ease of decomposition of the dyes of the formula I is very important. In addition, the The reaction rate in the process according to the invention is surprisingly higher than with the DT-OS method carried out at higher temperatures.

Another great advantage of the new method is that the dyes can be produced with practically any anions; either determined one passes the anion through the acid to be used as the condensing agent or one after the condensation by double conversion a new anion. As the solubilities the dyes are very strongly influenced by the anion, you can use them as required control by the choice of anion.

If, on the other hand, one has a poorly soluble anion from the start, so it is difficult to exchange this for another because you have to do this in the Usually the dye bases, which are generally not very stable, are required as an intermediate stage.

In the following examples, parts and percentages relate to unless otherwise noted, by weight.

Example 1 To a solution of 900 parts of methanol, 303 parts of 1,), 3-trimethyl-2-methyleneindoline-; laldehyde and 250 parts of 2,4-dimethoxyaniline become 80 parts of formic acid at 20 to 30 ° C added. The reaction solution is stirred for 15 to 30 minutes at 20 to 30 ° C, then 148 parts of sulfuric acid (96 percent) are added dropwise at 15 to 250C with cooling, whereby the dye precipitates as hydrogen sulfate. The dye is sucked off after the reaction mixture was cooled to 5 to 100C, with 900 parts of methanol Washed 5 to 100C and dried at 500C.

Yield: 580 parts of the dye of the formula this corresponds to 89.2% of the total

The dye dissolves excellently in water and stains acid-modified ones Polyacrylonitrile fibers in a brilliant, thoroughly yellow tone.

The following table shows the influence of solvents and condensing agents the yield when working under otherwise identical conditions can be seen: Tabel E.g. solvent org. Acid mineral acid yield 2 isobutanol formic acid sulfuric acid 92.6% (1100 parts) (80 parts) (148 parts) 3 n-propanol formic acid sulfuric acid 91.7% (900 parts) (144 parts) (148 parts) 4 dioxane formic acid sulfuric acid 91.3 % (900 while) (80 parts) (148 parts) 5 butyrolactone formic acid sulfuric acid 87.4 % (900 parts) (80 parts) (148 parts) 6 ethanol acetic acid phosphoric acid 85% 87.1 % (900 parts) (100 parts) (165 parts) 7 methanol acetic acid sulfuric acid 90.0% (900 parts) (180 parts) (148 parts) 8 methanol propionic acid sulfuric acid 85.5% (900 parts) (120 parts) (148 parts) 9 methanol lactic acid sulfuric acid 85.5% (900 Parts) (125 parts) (148 parts) 10 methanol chloroacetic acid sulfuric acid 84.6% (900 parts) (150 parts) (148 parts) 11 methanol diglycolic acid sulfuric acid 80.7 % (900 parts) (210 parts) (148 parts) 12 methanol 3-chloro-sulfuric acid 92.0% (900 parts) propionic acid (148 parts) (170 parts) 13 methanol benzoic acid sulfuric acid 90.4 ffi (900 parts) (200 parts) (148 parts) Example 14 To a Solution of 600 parts of methanol, 201 parts of 1,3,3-trimethyl-2-methyleneindoline - # - aldehyde and 230 parts of 2,4-dimethoxyaniline become 192 parts of citric acid at 20 to 30 ° C added.

The reaction solution is stirred for 30 minutes at 20 to 30 ° C (during this the dye precipitates), then cooled to 5 to 1000.

The precipitated dye is filtered off with suction and mixed with 600 parts of methanol Washed from 5 to 1000. After drying at 50 ° C., 447 parts of the dye are citrate received: 89.4% of theory

Example 15 In Example 14, citric acid is replaced by 150 Parts of tartaric acid, 352 parts of the dye tartrate are obtained: 70.6% of theory.

Example 16 In Example 14, the citric acid is replaced by 190 Parts of p-toluenesulfonic acid with 500 parts of isobutanol as solvent are obtained in this way 463 g of the dye p-toluenesulfonate: 90.5% of theory

Example 17 To a solution of 900 parts of chlorobenzene, 503 parts 1,3,3-trimethyl-2-methyleneindoline - # - aldehyde and 230 parts of 2,4-dimethoxyaniline 144 parts of formic acid are added dropwise with cooling at 20 to 30 ° C. After 5 to The dye precipitates out for 10 minutes. The reaction mixture is cooled to 1000, the dye is filtered off, washed with 900 parts of chlorobenzene and dried at 50.degree.

Yield 545 parts of the dye of the formula this corresponds to 94.7% of the total

The chlorobenzene of Example 17 can be prepared by the following organic solvents be replaced: Example Solvent Dye Yield 18 Toluene 93.8% 19 benzene 93.5 ffi 20 chloroform (700 parts) 64.1 ffi 21 perchlorethylene 94.7 ß Example 22 To a solution of 600 parts of toluene and 201 parts of 1,3,3-trimethyl-2-methyleneindoline-G * aldehyde and 150 parts of 2,4-dimethoxyaniline become 122 parts of benzoic acid at 20 to 30 ° C added. The reaction solution is stirred for 30 minutes at 20 to 30 ° C (during the dye precipitates) and then cooled to 5 to 10 ° C. The failed dye is filtered off and washed with 600 parts of toluene. After drying at 500C 406 parts of the dye benzoate obtained: 88.4 ß of theory

EXAMPLE 23 180 parts of acetic acid (100%) are added to a solution of 1000 parts of toluene, 303 parts of 1,3,) trimethyl-2-methyleneindoline-e) aldehyde and 230 parts of 2,4-dimethoxyaniline with cooling at 20 to 300C added dropwise. The dye crystallizes out after approx. 15 minutes. The reaction mixture is cooled to 1000, the dye is filtered off, washed with 800 parts of toluene and dried at 50.degree. Yield 542 parts of the dye of the formula this corresponds to 91.3% of the total.

EXAMPLE 24 51 parts of formic acid are added to a solution of 221 parts of water-moist 1,3,3-trimethyl-2-methylene-indoline-6-faldehyde = 192 parts of dry aldehyde, 117 parts of p-anisidine and 640 parts of isobutanol, with cooling at 20 to 30 ° C. The reaction solution is stirred for half an hour at 20 to 25 ° C, then while cooling at 20 to 30 ° C by dropwise addition of 95 parts of conc. Sulfuric acid precipitated the dye. After the reaction solution has cooled to about 100 ° C., the dye is filtered off with suction and washed out with 64 parts of isobutanol. After drying at 50 ° C. there are 375 parts of a dye of the formula obtained: 94.7% of theory

The table below lists the yields which are obtained with equal parts of 1,3,3-trimethyl-2-methyleneindoline - # - aldehyde and p-anisidine using the specified solvents and condensation agents: Table Ex. Solvent org. Acid mineral acid yield 25 isobutanol formic acid conc. Hydrochloric acid 86.1 ffi (600 parts) (88 parts) (100 parts) 26 methanol formic acid o-phosphorus 98.5% (650 parts) (51 parts) acid 85% (110 parts) 27 methanol glacial acetic acid o-phosphorus - 96.8% (650 parts) (66 parts) acid 85% (110 parts) 28 acetone formic acid o-phosphorus 88.4% (450 parts) (88 parts) acid 85% (110 parts) Example 29 66 parts of glacial acetic acid are added dropwise with cooling at 20-30 ° C. to a solution of 201 parts of 1,3,3-trimethyl-2-methyleneindoline-aldehyde, 123 parts of p-anisidine and 600 parts of toluene. After 5-20 minutes, the dye precipitates, is filtered off with suction and washed with 500 parts of toluene. After drying at 50 ° C., 338 parts of the dyestuff of the formula are obtained obtain; 92.3 ffi d. Th.

Example 30 In Example 20, the 66 parts of acetic acid are replaced by 51 parts of formic acid, 318 parts of the formate of the dye are obtained are 93.0 ß d.Th.

Example 31 To a solution of 201 parts of 1,3,3-trimethyl-2-methyleneindoline - # - aldehyde, 123 parts of p-anisidine and 600 parts of methanol become 210 parts of citric acid at 20 to 300C added. After 5 to 20 minutes, the dye citrate precipitates, which is suctioned off and is washed with 500 parts of methanol. After drying at 50 ° C., 451 Parts of the dye citrate obtained: 90.0 ß of theory

Example 32 In Example 31, citric acid is replaced by 165 Parts of tartaric acid, 327 parts of the dye tartrate are obtained: 71.0%.

Example 33 In Example 31, the citric acid is replaced by 190 Parts of p-toluenesulfonic acid, 440 parts of the dye p-toluenesulfonate are obtained: 91.7%.

The following table summarizes the results of the condensation of various 2-methylene indoline «Waldehydes with aromatic amines: Ex. 1-X-3,3-dimethyl-2-methylene amine solvent. org. Acid mineral acid yield indoline - # - aldehyde 34 methyl p-chloroaniline methanol formic acid phosphoric acid 87.4% 35 methyl p-toluidine methanol formic acid phosphoric acid 88.5% 36 ethyl p-anisidine isobutanol formic acid sulfuric acid 91.7% 37 benzyl p-anisidine methanol Citric acid - 90.8% 38 methyl-5-chloro-2,4-dimethoxy-methanol formic acid phosphoric acid 91.5% aniline 39 methyl-5-methyl-p-anisidine isobutanol formic acid sulfuric acid 89.3% 40 methyl-5-methoxy - p-anisidine methanol formic acid sulfuric acid 92.5% 3 part 41 A mixture of 235.5 parts of 5-chloro-1,3,3-trimethyl-2-methyleneindoline aldehyde, 171 parts of hexahydrocarbazole, 600 parts of methanol and 50 parts of formic acid is heated to 30 - 35 ° C for 30 minutes, a clear yellow color solution forms. By adding dropwise 230 parts of 85% phosphoric acid at 20.degree.-30.degree. C., the dye is precipitated, filtered off with suction at 10.degree. C. and washed out with 600 parts of methanol. After drying at 50-60 ° C., 545 parts of the dye of the formula are obtained obtain; 93.4% d. Th.

The formic acid can be replaced by 70 parts of glacial acetic acid or 190 parts Replace p-toluenesulfonic acid with the same yield of the dye.

EXAMPLE 42 50 parts are added to a solution of 201 parts of 1,3,3-trimethyl-2-methyleneindoline - # - aldehyde, 133 parts of 2,3-dihydro-2-methylindole and 600 parts of methanol at 20.degree.-30.degree. C. with cooling Formic acid is added. The reaction solution is stirred at 20-30 ° for 30 minutes, then 230 parts of 85% strength phosphoric acid are added with cooling and, after cooling to about 10 ° C., the dye is filtered off with suction and washed with 500 parts of methanol. After drying at 50-60 ° C., 472 parts of the dye of the formula are obtained obtain; 88.6% of theory

If the 2,3-dihydro-2-methylindole is replaced by others in the example Amines, other yellow dyes with high purity are obtained.

Example amine yield HH B. HH H HR 44 3 <H 163 parts 91.5% HH Example amine yield OH I3H 2 H 148 parts 89.7 ffi H 46 Ow H 121 parts 86.9% HH Liquid adjustments of dyestuffs of the formula I Example 47 200 parts of formic acid are added at 20-30,000 to a solution of 201 parts of 1,3,3-trimethyl-2-methyleneindoline - # - aldehyde, 153 parts of 2,4-dimethoxyaniline and 400 parts of butyrolactone added. After 5 minutes, a storage-stable, concentrated dye solution of the dye is obtained. the formula If the 200 parts of formic acid in Example 47 are replaced by 200 parts of glacial acetic acid, 200 parts of lactic acid or 200 parts of benzoic acid, storage-stable, concentrated dye solutions are also obtained.

Example 48 200 parts of formic acid are added at 20 to 50 ° C. to a solution of 201 parts of 1,3,3-trimethyl-2-methyleneindoline - # - aldehyde, 123 parts of p-anisidine and 300 parts of propylene glycol. After 3 minutes, a storage-stable, concentrated solution of the dye of the formula is obtained In Example 48, the 300 parts of propylene glycol can be replaced with 300 parts of butyrolactone, 300 parts of methyl diglycol or 300 parts of glycol acetate.

Example 49 A mixture of 235.5 parts of 5-chloro-1,3,3-trimethyl-2-methyleneindolineQJ-aldehyde, 171 parts of hexahydrocarbazole, 300 parts of ethylene glycol and 200 parts of formic acid is heated to 30 ° C. for 30 minutes. A clear, yellow-brown, storage-stable dye solution of the dye of the formula is formed

Claims (6)

Claims 1. Process for the preparation of pure cationic dyes of the formula in which the radicals A are identical or different alkyl radicals, A1 optionally substituted alkyl or aralkyl, A2 is hydrogen or, together with the nitrogen, an optionally substituted 5- or 6-ring fused to the phenyl ring in the o-position, and A is an anion, the rings B and E can also carry further substituents by condensation of aldehydes of the formula II with amines of the formula III in the presence of acid and solvent, characterized in that an aliphatic or aromatic carboxylic or sulfonic acid is used as the acid and an organic solvent is used as the solvent and that the condensation is carried out at temperatures between approximately 0 and 50, preferably 20 and 40 ° C. 2. The method according to claim 1, characterized in that one dyes of the formula in which R1 is methyl, ethyl or benzyl, R2 is hydrogen or, together with the nitrogen and the optionally substituted phenyl radical, a 5- or 6-membered ring with one or two heteroatoms can be fused onto another 6-membered carbocycle, R3 is hydrogen, Chlorine, bromine, methyl, ethyl, methoxy or ethoxy, 4 R is hydrogen, chlorine, bromine, methoxy or ethoxy, Y is hydrogen, chlorine, methoxy, ethoxy, methoxycarbonyl, ethoxycarbonyl or benzyl and Ae is an anion. 3. The method according to claim 1, characterized in that A2 is hydrogen is. 4. The method according to claim 1, characterized in that A2 together with the phenyl ring marked by E the remainder of 2,3-dihydroindole, 2,3-dihydro-2-methylindole, 2,3-dihydro-2-phenylindole, 2,3-dihydro-2,3,3-trimethylindole, hexahydrocarbazole, 1,2,3,4-tetrahydroquinoline, 1,2,3,4-tetrahydro-6-methoxyquinoline, 1,2,3,4-tetrahydroquinoxaline or 1,2,3,4-tetrahydro-4-methyl-quinoxaline. 5. The method according to claim 1, characterized in that as Acid formic, acetic or propionic acid and an alkanol with 1 up to 4 carbon atoms are used. 6. The use of the dyes prepared according to claim 1 or 2 for dyeing anionically modified fibers, especially polyesters and acrylonitrile polymers.