WO1991001292A1

WO1991001292A1 - Method for the preparation of nitroanilines

Info

Publication number: WO1991001292A1
Application number: PCT/EP1990/001180
Authority: WO
Inventors: Theodor Papenfuhs; Reiner Hess; Reinhold Deubel; Rüdiger JUNG
Original assignee: Hoechst Aktiengesellschaft
Priority date: 1989-07-20
Filing date: 1990-07-19
Publication date: 1991-02-07
Also published as: CA2063817A1; EP0483241A1; JPH04506805A; DE3924092C1

Abstract

Disclosed is a method for the preparation of nitroanilines of the formula (I), in which R1? and R2? are a hydrogen or a C1?-C4? alkyl group and R is a hydrogen atom or a nitro group, by reacting, at temperatures of about 40 C to about 120 C and at atmospheric or elevated pressure in the presence of at least one ionic or non-ionic surface-active agent, 1 mole of anitrochlorobenzene of the formula (II), in which R is as defined above, with about 200 to about 4000 molar % of a compound of the formula (III), in which R1? and R2? are as defined above.

Description

description

Process for the preparation of nitro-anilines

The invention relates to an improved process for the preparation of mononitro- or dinitro-anilines in very good yields and high purity by reacting mononitro- or dinitro-chlorobenzenes with ammonia or amines in the presence of surface-active compounds.

The nitro-anilines mentioned below are important intermediates in the manufacture of dyes and pigments as well as in the manufacture of pharmaceuticals and plant protection products. These are, for example, the compounds N-methyl-4-nitro-aniline, N, N-dimethyl-nitro-aniline, N-methyl-2-nitro-aniline, N, N-dimethyl-2-nitro-aniline , 2,4-dinitro-aniline, 2,4-dinitro-N-methyl-aniline and 2,4-dinitro-N, N-dimethyl-aniline.

2,4-Dinitro-aniline is prepared, for example, by rearrangement of N, 4-dinitro-acetanilide, which is thermally labile, in acetic acid at 0 to 70 ° C. with subsequent hydrolysis in 200 to 3800 mol%

Sulfuric acid of the resulting 2,4-dinitro-acetanilide to the desired product (PL 131799 from 04/30/87). This type of production produces a highly acid-contaminated wastewater with strong organic contamination, which has to be disposed of in a very complex manner. The security aspects of the rearrangement of the thermally unstable

Dinitro output connection are an additional problem with this approach. 2,4-Dinitro-aniline is also prepared by reacting a melt of 2,4-dinitro-chlorobenzene with ammonia at 180 ° C in 71% yield (CN 86100379 from 1/19/86). This reaction variant harbors the task of homogeneous mixing of the two reactants ammonia and 2,4-dinitro-chlorobenzene, which is certainly difficult for industrial production. In addition, after the excess ammonia has been drained off, the ammonium chloride formed in the reaction is completely washed out of the 2,4-dinitro-aniline. Because of the high melting point of the end product, the reaction must be carried out up to an alarmingly high temperature level (180 ° C), at which an explosive decomposition cannot be ruled out with a longer reaction time.

A further possibility of producing 2,4-dinitro-aniline is described by Gitis et al. (US 3398194) describes the representation by reacting 2.2 ^, -4.4 ^l tetranitro-diphenyl ether in dimethylformamide with ammonia passed through at room temperature. The very labile and extremely reactive starting product of this reaction - the 2, 2 '-4,4'- etr nitro-diphenyl ether - is produced by reaction of 2,4-dinitro-phenol with 2,4-dinitro-chlorobenzene by base catalysis, whereby intermediate thermally extremely unstable

2,4-dinitro-phenolate is formed. In addition, the preparation of the diphenyl ether adds a process step for the normal preparation of the 2, -dinitro-aniline from 2,4-dinitro-chlorobenzene, which prohibits the production by this reaction route for economic reasons.

Other of the nitronilines described by way of example above are also prepared by reacting the corresponding alkylamine with 2,2'-4.4 ^l -tetranitro-diphenyl ether, this procedure, because of its two stages, is principally the case Costs for technical production are soaring and therefore, but also because of the higher chemical costs and the cleaning processes required at every stage, must be rejected for ecological and economic reasons.

DE-OS 2725957 of December 22, 2007 describes the preparation of 2,4-dinitro-N-methyl-aniline as follows: 203.5 parts of 2,4-dinitro-chlorobenzene are suspended in 390 parts by weight of water by stirring at room temperature . This suspension is brought to 85 ° C., after which the addition of 120 parts by volume of 41.5% strength methylamine solution is started. During this exothermic reaction, the temperature rises to 88 ° C. The description now reads: "The emulsion solidifies slowly and a thick yellow crust forms on the piston wall." By adding 103 parts by volume of 30% sodium hydroxide solution, the crust dissolves, combined with a drop in the reaction temperature. With the procedure described, a yield of 97.8% of theory is obtained. Th

2,4-dinitro-N-methyl-aniline, based on 2,4-dinitro-chlorobenzene.

The difficulties of the procedure described can already be seen from the description text (DE-OS 2 725 957):

1. Strongly exothermic reaction, so strong heat and temperature rise of the reaction mixture, i.e. in industrial production with significantly deteriorated surface / volume ratios, the heat can lead to uncontrollable decomposition.

2. Crust formation on the flask wall, ie in the technical reaction apparatus accumulation of reaction residues which may no longer be removed and which have to be removed mechanically at great expense. Many users try to counter the disadvantage of this reaction by using solvents such as formamide (DD 229017) or dimethylformamide. However, the process with solvent must be carried out at temperatures around 100 ° C. and has a poorer yield (91%) than that described above.

As an alternative to the production processes of 2,4-dinitro-aniline shown above, the reaction of 2,4-dinitro-phenol alkyl ethers (JP 50/126625) or 2,4-dinitro-phenol (JP 49/14431) described. Here, for example, 2,4-dinitro-aniεol is treated with ammonia in a non-water-miscible solvent for 6 hours at high pressure. No information was given there about yield and purity.

In another example, 100 parts of 2,4-dinitro-phenol in 420 parts of water are reacted with 180 parts of ammonium sulfate and 120 parts of liquid ammonia in an autoclave at 165 to 170 ° C. for 10 hours. This gives 95 parts of 2,4-dinitro-aniline, corresponding to a yield of 94.5% of theory. Th. Based on 2,4-dinitro-phenol.

A disadvantage of the described production variant from 2,4-dinitro-phenol - also from the 2,4-dinitro-phenol alkyl ethers - is on the one hand the accumulation of a highly salt-contaminated wastewater - the mother liquor of the reaction - but on the other hand, much more serious, that The fact that the 2,4-dinitro-phenol and the 2,4-dinitro-phenol alkyl ethers are prepared from 2,4-dinitro-chlorobenzene by nucleophilic exchange, that is to say on the way from 2,4-dinitro-chlorobenzene to the second , 4-Dinitro-aniline, a further process step with chemical and apparatus costs and cleaning procedures is added. There was therefore a need for an improved and technical production process for nitro-anilines, some of which were mentioned above by way of example, that in one process step, starting from nitro-chlorobenzene derivatives, at the lowest possible temperature, if possible without distillation or others To use separation solvents required, leads in good yield and high purity to products that can be separated by simple filtration if possible.

It has now surprisingly been found that nitro-anilines of the general formula (I)

in which R- ^, R2 represents a hydrogen atom or a

Alky1 (C - ^ - C ^) group and R is a hydrogen atom or a

Nitro group mean in very good yields and high

Purity can be produced in one process step by using 1 mole of a nitro-chlorobenzene of the general type

Formula (II)

in which R has the meaning given above, with about 200 to about 4000 mol%, preferably about 200 to about 1200 mol%, particularly preferably about 200 to about 600 mol% of a compound of the general formula (III)

^• H - N (III) in which R ^ and R _{2 have} the meanings given above, at temperatures from about 40 ° C to about 120 ° C, preferably about 50 ° C to about 90 ° C, particularly preferably about 55 ° C to about 80 ° C in The presence of at least one ionic or nonionic surface-active compound.

The resulting nitro-anilines are separated off by filtration and washed after the reaction. The yields are very good (> 98% of theory), the purities of the products are also (degree of purity (HPLC)> 99%). Also, no caking and inclusions take place in the course of the reaction, i.e. any product residues remaining in the reaction vessel are not to be expected according to the method according to the invention. In addition, there is a great advantage that the "homogenization" of the reaction mixture achieved by the addition of surface-active compounds enables the reaction temperature to be reduced to a very low value, which allows the non-corrosive but also expensive apparatus materials usually used in such media How, for example, Haoytelloy C, in favor of steel, should be dispensed with, would ensure a high economic advantage for the method according to the invention.

The surface-active compounds include both ionic (anionic and cationic) and nonionic surface-active compounds. The ionic auxiliaries include anionic surface-active compounds, such as, for example, the alkali metal salts of alkyl (C ₁₄ -C ₁₈ ) sulfonic acids, aralkyl (C ₁₂ -C ₁₄ ) sulfonic acids, for example sodium dodecylbenzoyl sulfonate, or of alkyl (C ₃ - _ζ ) -naphthalenesulfonic acids, for example l-isopropyl-naphthalene-2-sulfonic acid sodium, or the alkali metal salts of saturated or unsaturated higher fatty acids (Ci ^ -C ^), for example sodium laurate, Sodium myristate, sodium palmitate, sodium stearate or sodium oleate, furthermore the alkali metal salts of alkyl (C ₁₂ -C ₃₅ ) sulfates, ie of sulfuric acid esters of higher fatty alcohols, such as, for example, lauryl sulfate, tridecyl sulfate, myristyl sulfate, pentadecyl sulfate,

Cetyl sulfate, octadecyl sulfate, or oleyl sulfate, or of phosphoric acid esters of higher fatty alcohols or of phenol.

The ionic auxiliaries also include cationic surface-active compounds, such as, for example, primary, secondary or tertiary amine salts, guaternary ammonium salts or pyridinium salts, preferably the chlorides, sulfates or methyl sulfates, and amphoteric surface-active compounds, for example those of the amino salt type sodium or amino amino acid type, for example amino amino acid type sulfon, for example amino amino acid type sulfon Methylamino-ethylεulfonic acid sodium, or of the betaine type.

Non-ionic surface-active compounds are those of the polyethylene glycol or polyhydroxy alcohol type. Examples include the alkyl polyglycol ethers, alkyl phenyl polyglycol ethers,

Alkyl naphthyl polyglycol ether, fatty acid polyglycol ether ,. Fatty acid amide polyglycol ether and fatty amine polyglycol ether.

Typical examples of these surface-active compounds can be found, for example, in "Surface Active Agents and Detergents", Volume I, by A.M. Schwarz and J.W. Perry, or in "Catalyεiε in Micellar and Macromolecular Systems" by J.H. Fendler and E.J. Fendler, Academic Press N.Y. 1975.

Some surface-active compounds which are preferably used according to the invention are given below.

Compound 1: 30% aqueous solution of alkyl (C ₁₂ -C ₁₄ ) dimethyl betaine. Compound 2: 30% aqueous solution of a diolsulfonic acid phenol-formaldehyde condensation product.

Compound 3: disulfonic acid creole-formaldehyde condensation product.

Compound 4: sulfated creole-phenol condensation product as 35% aqueous solution.

Compound 5: Novolak derivative of the formula

Compound 5a: Novolak derivative of the above general formula R = -C0-CH ₂ -CH (S0 ₃ Na) -COONa

R = -CO-Ph

Sum n = 100-110 x = 5

Compound 6: dimethylnaphthalene-εulfonic acid formaldehyde condensate of the formula

Compound 7: sulfomethylated cresol-phenol-formaldehyde condensate

It is also possible to use a larger molar excess than 4000 mol% of a compound of the general formula III. However, since no greater positive effect is achieved here, the use of such larger amounts merely means a reduction in the economics of the method.

The process according to the invention can be carried out either at normal pressure or at elevated pressure, as well as discontinuously or continuously.

The process according to the invention will be explained in more detail by the examples below. However, it should be pointed out that the invention is neither restricted solely to the use of the nitroanilines mentioned therein nor exclusively to the surface-active compounds listed in these examples and above.

Example 1 (2,4-Dinitro-N-methyl-aniline)

In a 1 1 four-necked flask with stirrer, dropping funnel,

340 ml of water, 270 g (1.33 ol) of 2,4-dinitro-chlorobenzene and 10 g (3.7% by weight) of compound 5a are placed in the contact internal thermometer and heating bath and heated to 50 ° C. with stirring. A mixture of 130 ml is added to the well-distributed suspension

Monomethylamine solution, 40% (1.67 mol), 110 ml of 35% NaOH (0.96 mol) and 160 ml of water were added dropwise at 50 ^° C. in the course of 2 hours. The mixture is subsequently stirred at 50 to 55 ° C. for 11 hours and the product suspension is suctioned off from the mother liquor after stirring to room temperature. After suctioning off and washing with 500 ml of water, 288 g of a 10% water-moist light yellow fine crystalline product with a melting point of 179 to 182 ° C, corresponding to a yield of 98.9% of theory. Th. With a purity of 98.5% according to HPLC (HPLC = High Performance Liquid Chromatography).

Example 2 (2-nitro-N, N-dimethyl-aniline)

451 g of 40% dimethylamine solution (4.02 mol) and 10 g of compound 6 are placed in a 2-1 four-necked flask equipped with a stirrer, internal thermometer, heatable dropping funnel and heating bath and heated to 55 to 60 ° C. with stirring. 288 g (1.83 mol) of 2-nitrochlorobenzene are added dropwise over the heatable dropping funnel in the course of 4 hours. After the addition has ended, the mixture is stirred at 60 to 70 ° C. for 8 hours and then cooled to 30 ° C. with stirring. 150 g of 35% sodium hydroxide solution (1.3 mol) are allowed to run in with stirring. The lower phase is then separated off in a separating funnel and the upper phase is worked up to recover dimethylamine. The lower phase - the crude product - is washed twice, each with 200 ml of water, separated and isolated. For drying, the mixture is briefly distilled in vacuo. 283 g of 2-nitro-N, N-dimethyl-aniline are obtained as an oily yellow-brown liquid in a purity of 98.8% by HPLC, corresponding to a yield of 93.2% of theory. Th ..

Example 3 (3,4-Dinitro-aniline)

1000 ml of aqueous ammonia, 16% (9.4 mol), and 8 g (2% by weight) of compound 6 are placed in a 2-1 four-necked flask equipped with a stirrer, internal thermometer and heatable dropping funnel and 8 g (2% by weight) of the compound 6 and stirred at 55 ° C. heated. It now begins with the addition of 406 g (2 mol) of 2,4-dinitro-chlorobenzene as a melt (dropping funnel has a jacket temperature of 60 ° C.) within four hours he follows. After this time, the mixture is stirred at 55 ° C. for 20 hours and the 2,4-dinitro-aniline obtained is suction filtered through a G-3 glass frit. It is washed with 500 ml of water and sucked dry for 30 min. 412 g of 2,4-dinitro-aniline, which is 16% water-moist, are obtained. This corresponds to a yield of 94.5% of theory. Th .. The product has a melting point of 179 to 180 ° C and a purity of 97.8% according to HPLC.

Analogously to this example, the usability of the above-mentioned compounds 1 to 7 as surface-active additives for the preparation of nitroanilines was checked in several experiments. Very good yields and purities of very finely divided 2,4-dinitro-aniline were obtained in all cases.

Example 4 (2,4-Dinitro-aniline)

350 ml of water, 240 ml of ammonia, 25% strength (3.52 mol) and 1.9 g of compound 6 are placed in a 1 liter glass autoclave with stirrer and heated pump, and after flushing with nitrogen and closing the autoclave to 55 ° C. heated up. At this temperature, 187 g (0.92 mol) are then stirred within four hours

2,4-Dinitro-chlorobenzene pumped in. When the addition is complete, the mixture is heated to 80 ° C. and stirred for a further 16 hours. After this period of time is cold stirred to room temperature ^'and the autoclave is first expanded and then deflated. One obtains 182 g of 2, -Dinitro-aniline with a residual moisture of 9% by suction, corresponding to a yield of 99.1% of theory. The dried product has a melting point of 179.5 to 181 ° C and a purity of 98.7% by HPLC. Analogously to the reaction mode and batch size in this example, all the surface-active compounds listed above were again used, and very good results were obtained both from the yield and from the purity of the 2,4-dinitro-aniline obtained.

Claims

1. Process for the preparation of nitro-anilines of the general formula (I)

in which R ^, R _{2 is} a hydrogen atom or an alkyl (C - C ₄ ) group and R is a hydrogen atom or a nitro group, characterized in that 1 mol of a nitro-chlorobenzene of the general formula (II)

in which R has the meaning given above, with about 200 to about 4000 mol% of a compound of the general formula (III)

R

/ 1

H - N (III)

^ ^R 2

in which R ^ and R _{2 have} the meanings given above, at temperatures of about 40 ° C to about 120 ° C in the presence of at least one ionic or non-ionic surface-active compound.

2. The method according to claim 1, characterized in that is reacted at temperatures of about 50 ^C C to about 90 ° C.

3. The method according to at least one of claims 1 and 2, characterized in that the reaction is carried out at temperatures of about 55 ° C to about 80 ° C.

4. The method according to at least one of claims 1 to 3, characterized in that in the presence of alkali metal salts of alkyl sulfonic acids,

Aralkylsulfonic acids, saturated or unsaturated higher fatty acids, alkyl sulfates or phosphoric acid esters of higher fatty alcohols or phenol as anionic surface-active compounds.

5. The method according to at least one of claims 1 to 3, characterized in that in the presence of amphoteric surface-active compounds of the amino salt type or betaine type, ionic surface-active compounds are reacted.

6. The method according to at least one of claims 1 to 3, characterized in that alε nonionic surface-active compounds are reacted in the presence of compounds of the polyethylene glycol or polyhydroxy alcohol type.

7. The method according to at least one of claims 1 to 3, characterized in that in the presence of alkyl (C ₁₂ -C ^ ₄ ) dimethyl betaine in the form of a 30% aqueous solution, a ε-sulfonic acid

Formaldehyde condensation product in the form of a 30% aqueous solution, a sulfonic acid

Creole-formaldehyde condensation product, a sulfated creole-phenol condensation product in the form of a 35% aqueous solution, a sulfomethylated creole-phenol-formaldehyde condensate, a dimethylnaphthalene-sulfonic acid formaldehyde condensate or a novolak derivative as a surface-active compound.

8. The method according to at least one of claims 1 to 3, characterized in that in the presence of salts primary, secondary or tertiary amines, guaternary ammonium salts or pyridinium salts as cationic surface-active compounds.

9. The method according to at least one of claims 1 to 8, characterized in that with about 200 to about 1200 mol% of the compound of the general formula III is reacted.

10. The method according to at least one of claims 1 to 9, characterized in that reacted with about 200 to about 600 mol% of the compound of general formula III.

11. The method according to at least one of claims 1 to 10, "characterized in that in the presence of about 0.1 to about 10% by weight of surface-active compound, based on the starting compound of the general formula II, is reacted.

12. The method according to at least one of claims 1 to 11, characterized in that in the presence of about 0.2 to about 5% by weight of surface-active compound, based on the starting compound of the general formula II, is reacted. -

13. The method according to at least one of claims 1 to 12, characterized in that in the presence of about 0.5 to about 3% by weight of surface-active compound, based on the starting compound of the general formula II, is reacted.

14. The method according to at least one of claims 1 to 13, characterized in that one implements at normal pressure or elevated pressure.

15. The method according to at least one of claims 1 to 14, characterized in that one carries out the reaction batchwise or continuously.