DE3316465A1 - METHOD FOR PRODUCING ORTHO-PHENYLENE DIAMINE - Google Patents

Description

Process for the preparation of ortho-phenylenediacm

The invention relates to a process for the production of the o-plifnylcnuiamine which can be used as an excess product in the production of pharmaceutical and pesticide active ingredients. FJr fi ndunosqr-.i ß * ird (Kiese Ve r Ii i ndii η ι] axir connections of the d11nomeinen I-'rjrincl (I)

- where X stands for hydrogen or chlorine - produced, by the connection of the common «· ί.ΐι». · η formula (I) in w.it'r] ^ i ;;; i,

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ammoniacal medium in the presence of an active hydrogenation catalyst is hydrogenated with hydrogen or a hydrogen-containing gas.

The known processes for the preparation of o-phenylenediarain are based primarily on the reduction of o-nitroaniline. In the known methods of reduction iron, zinc or tin are used as reducing agents (Winnacker-Küchler: Ketniai technologia I., pp. 742-748, Müszaki Könyvkiado, Budapest 1962) or sodium sulfide in aqueous medium (FIAT Final Report No. 1313) was used.

Recently, the reduction of the o ~ nitroaniline as catalytic reduction carried out. The catalytic hydrogenation can in the gas phase with a copper catalyst (Brown, Carrick: J. Am. Chetn. Soc. 4JL, 439) or a palladium catalyst made with puller earth as the carrier (Monsanto Chetnipels, British Patent No. 1,077,920 / 1967 /) will. In the case of hydrogenation in the liquid phase, generally in a solvent as a catalyst Raney nickel (Chem. Zvesti 2 ,, 114/1948 /) or applied to a carrier Palladium or platinum catalysts (du Pont de Nemours, DE-AS No. 2,461,615 / 1975 /; US-PS No. 3,230,259) used.

The o-phenylenediamine can also by the reduction of o-dinitrobenzene are produced; but this connection is 5 manure practically inaccessible on an industrial scale.

The production of o-phenylenediamine by ammonolysis of o-dichlorobenzene is known from some Japanese patents (Japanese patents 95 615-95 617, Toyo Soda Mfg.Co.Ltd / 1977 /). The ammonolysis is carried out at 200 ⁹ C in the presence of a copper catalyst and lasts for l6 hours.

The amination of the aniline to o-phenylenedianine can with a nickel catalyst containing Mg, Sr and Zn-Cxyd made at 350 ° C and a pressure of 300-400 bar

and delivers moderate yields (du Pont de Nemours, DE-AS No. 2 114 170/1970 /).

The main disadvantage of the non-catalytic reductions of o-nitroaniline is that by-products and waste water must be rendered harmless in large quantities. The catalytic reduction proceeding in the vapor phase takes place at temperatures above 250 C, and by the to increase the hydrogenation rate applied pressure, the temperature must be increased even more so the gas phase is retained.

The suspended catalyst processes operating in the liquid phase have become almost without exception realized as a discontinuous process. The o-nitroaniline is in suitable organic solvents (aromatic hydrocarbons, esters or alcohols) dissolved, the catalyst is suspended in the solution and the hydrogenation is carried out with vigorous stirring. The use of these processes on an industrial scale makes the regeneration of large quantities more organic Solvent required.

The o-nitroaniline is itself an intermediate product prepared in several reaction steps, and therefore are for Production of o-phenylenediamine those multi-step processes really of interest, those of benzene or of Intermediate products with a lower degree of work-up (chlorobenzene, nitrobenzene) go out. These run via the o-nitroaniline Syntheses generally have the disadvantage that in the preparation of the o-bifunctional compound (o-chloronitrobenzene, o-nitroacetanilide) as a by-product twice the amount of p-isomer can be produced.

A proprietary process (Hungarian patent specification No. 175 397), which is based on the nitration of p-dichlorobenzene □ with subsequent amination and catalytic hydrogenation

runs, eliminates this disadvantage; in this procedure no isomeric by-products are formed.

The syntheses which do not proceed via the o-nitroaniline have not found their way into practice, despite the inaccessibility of the starting materials and the intensive use Reaction conditions the achievable yields are too low.

On an industrial scale, 9m is most widespread with the amination of o-chloronitrobenzene and the reduction of the o-nitroaniline obtained worked. The o-chloronitrobenzene always coincides with the isomeric p-chloronitrobenzene to, · the use of the former must therefore necessarily also include a utilization of the latter; in this case the production of o-phenylenediamine from o-chloronitrobenzene is advantageous.

Of the known processes, therefore, the most advantageous are those in which it is expedient to use o-chloronitrobenzene o-nitroaniline obtained and the 2-nitro-4-chloroaniline prepared from p-dichlorobenzene catalytically to o-phenylenediamine be hydrogenated.

In investigating the possibilities for preparing o-phenylenediamine, it has now been found that the hydrogenation in an aqueous medium containing 40-90%, advantageously 50-60% ammonia, can be carried out more advantageously than in organic solvents. Our own measurements have shown that the aqueous ammonia solutions containing more than 40% ammonia form a homogeneous reaction mixture with the various organic compounds, especially at temperatures above 100 ° C. This also applies to the compounds of the general formula (I). At 100 ^° C., the mixture of 30% ammonia, 30% water and about 20% 2-nitro-4-chloroaniline forms a single liquid phase. The presence of the ammonia is in the reaction medium

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a more favorable and constant pH given what the The activity of the palladium catalyst applied to activated carbon is favorably influenced. If the hydrogenation with the hydrogenolysis of the halogen takes place at the same time, the large excess of ammonia binds the hydrochloric acid formed and at the same time keeps the aramoniurachloride produced as a by-product in solution. When using organic Solvent must be expected with the precipitation of the salt, which is continuous especially when it is under pressure working devices causing difficulties «The excess of ammonia can come from the over 100 C warm hydrogenation mixture can simply be blown off. From the remaining aqueous solution, the o-phenylenediamine separates out in crystal form on cooling, while the ammonium chloride remains in solution. The efficiency of the separation of the target product o-phenylenediamine from the by-product Ammonium chloride can be increased by extraction.

The two products can also be separated by extraction without prior crystallization; in this case, the o-phenylenediamine solution and the Ammonium chloride solution separated from one another and worked up individually.

The use of aqueous ammonia as the reaction medium has another important benefit associated with it. The compounds of general formula (I) are industrially almost exclusively by ammonolysis of compounds of general formula (II)

Cl

- wherein the meaning of X is the same as above

manufactured. This ammonolysis must be included in any case

an excess of ammonia can be made. The compounds of the general formula (I) are isolated in the usual way, by boiling off the ammonia and removing the ammonium chloride. Will now the preparation of o-phenylenediamine by hydrogenation with the division of the compounds of the general formula (I) linked by ammonolysis, it is not necessary to isolate the compounds of the general formula (I). The mixture emerging from the amination reactor, which ammonia, water, the compound of the general formula (I) and contains ammonium chloride, can be passed directly into the hydrogenation reactor. There the aqueous suspension of the hydrogenation catalyst is added and hydrogen is passed in and continues to be homogeneous Remaining reaction mixture, the compound of general formula (I) is hydrogenated to o-phenylenediamine. Because the o-phenylenediamine Can be prepared most advantageously via these steps of amination and hydrogenation, ensures the direct coupling of the two reaction steps significant technical advantages.

According to the invention, the o-Phenylenediatnin is prepared by stirring the compound of the general formula (I) in a pressurized stirred tank at 100 ° C. with water containing preferably 50-60% ammonia to form a homogeneous mixture, 5-10% palladium activated carbon catalyst in a adding amount of 0.05-2% in the form of a 1-10% aqueous suspension, and at 100-160 ⁰ C and pressure bar hydrogenated by passing hydrogen or a hydrogen containing gas 60-200. Under these conditions the reaction is more than 98% within 20-60 minutes. The excess ammonia is blown off warm from the hydrogenated reaction mixture; the catalyst is filtered off. At least 80% of the o-phenylenediamine can be isolated from the aqueous solution by cooling, crystallization and filtration. The o-phenylenediamine is obtained from the remaining mother liquor by extraction with a

organic solvent removed. The ammonium chlorad Remains in the aqueous solution and can be obtained therefrom by evaporation. The ammonium chloride is a industrially usable product, so its separation has an economic advantage on the one hand, and it is on the other from the point of view of environmental protection it is advantageous that the salt does not end up in the waters together with the wastewater.

Chlorinated hydrocarbons such as chloroform are used as extraction agents for extraction, 1,2-dichloroethane, trichlorethylene, perchlorethylene,

It

1,1,2-trichloroethane, or benzene, toluene, ether or ester. If the extraction is carried out after the ammonia has been blown off without prior crystallization of the o-phenylenediamine is, the entire amount of o-phenylenediamine falls in the organic phase and is made from this by crystallization or evaporation isolated.

For the hydrogenation, a batchwise stirred reactor or one which is connected in series can be used Cascade reactor built into reactors or a continuously operating column or tube reactor is used will. The catalyst is kept in suspension in the reactor by mechanical stirring or by passing in the gas. The ammonia is recovered from the gas emerging from the reactor by washing with water under pressure. That Hydrogen gas is either vented or kept in circulation. Instead of hydrogen, hydrogen can also be used Gas from ammonia synthesis can be used.

Should the hydrogenation immediately start with the amination reaction are coupled, the procedure is as follows.

The compound of general formula (II) is stirred with 7O-9O% ammonia containing aqueous ammonia solution to form a homogeneous mixture and aminated at 180-220 ⁰ C. The amination can be discontinuous or continuous

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be made. After a reaction time of 20-40 minutes, the reaction mixture is cooled to 100-160 ° C. and poured into the Passed hydrogenation reactor, where after addition of the catalyst suspension the hydrogenation in the manner described takes place.

A pilot plant was set up for the continuous, coupled implementation of the amination and hydrogenation steps built, the puncture is explained on the basis of the accompanying illustration.

The o-chloronitrobenzene or 2,5-dichloronitrobenzene is from the dosing tank 2 by means of the dosing pump 6, the concentrated aqueous ammonia solution from the dosing tank 3 metered by means of the metering pump 7. After mixing, the reaction mixture forms a homogeneous liquid phase into the tubular reactor 9, where the amination takes place at 200-220.degree. The reaction mixture, that ammonia, Water, ammonium chloride and o-nitroaniline or 2-'nitro-: 4-chloroaniline is contained in a heat exchanger 10 100-160 C cooled and then introduced at the bottom of the hydrogenation reactor. There is also from the Dosierbshält 4 means the metering pump 8, the aqueous suspension of the Palladiura activated carbon catalyst fed. The hydrogenation gas, which is under 60-200 bar pressure, is also fed into the reactor at the bottom introduced. The reaction mixture runs through the hydrogenation reactor 11 and from there into the separator 12, where the ammonia-saturated gas is separated from the liquid phase. The gas is in the pressurized Absorber 13 passed, wc the ammonia is washed out with water. The resulting solution of the recovered Ammonia can be reused after adding some fresh ammonia. The separator 12 becomes the liquid Phase passed continuously into the heater 14. The ammonia released in the heater 14 by boiling becomes passed into the absorber 13 and absorbed there. The liquid phase emerging from the heater reaches the

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Filter 17 on which the catalyst is filtered off. The o-phenylene diamine and ammonium chloride-containing hot saturated solution is fed into the countercurrent extractor 15 in which is extracted from the liquid by the dose from the container 1 by means of the metering pump 5, the solvent o-phenylenediamine. The aqueous solution, which now only contains the ammonium chloride, is passed into the storage container 19. The solution of the solvent, which is warmly saturated with o-phenylenediamine, exits from the extractor 15 and enters the crystallization container 16, where it is cooled and finally fed to the filter 18, on which the o-phenylenediamine is separated off. The end product collects in the container 21. The mother liquor emerging from the filter 18, which still contains 2-5 % o-phenylenediamine, is collected in the storage container 20 and can be fed to the extraction again.

The invention is explained in more detail with reference to the following exemplary embodiments.

example 1

13.8 g of o-nitroaniline are placed in a heatable pressure vessel equipped with a stirrer. After adding The container is sealed with 18 g of water. 28 g of liquid ammonia are converted from a pressurized dosing tank added to the reactor and then heated its contents to 100 C with stirring. 40 mg of 10 # palladium activated carbon catalyst are suspended in 10 g of water. The suspension is placed in a hydrogenation reactor of 0.2 dm volume with a heat jacket and a perforated plate serving for gas distribution. The catalyst is through Introducing gas kept in suspension. The temperature of the reactor is regulated to 130 ° C. and its pressure to 100 bar. The mixture containing o-nitroaniline, ammonia and water is then pressed into the hydrogenation reactor by means of nitrogen. After a reaction time of 40 minutes, the supply of V / water

3316Λ65

shut off the substance and by opening the blow-off valve of the Ammonia blown off. Then the contents of the reactor are drained, the catalyst is removed by filtration. By cooling the warmly saturated solution, 8 g of o-phenylenediamine are separated off, which after drying at 101 ° C melts. A further 2.6 g of product with a melting point of 98 ° C. are obtained by evaporating the mother liquor.

Example 2

18 g of water and 28 g of liquid ammonia are added to 17.2 g of 2-nitro-4-chloroaniline in the manner described in Example 1. The suspension of 100 mg of 10% strength palladium activated carbon in 10 g of water is added to the hydrogenation reactor according to Example 1. Hydrogenation is carried out in the manner described in Example 1 for 60 minutes, Na ₁ Ch releasing the pressure, boiling off the ammonia and filtering the catalyst, o-phenylenediamine is obtained in an amount of 8.5 g by crystallization from the solution. The mother liquor is extracted three times with 20 ml of chloroform each time. Evaporation of the organic phase gives a further 2 g of o-phenylenediamine. 5 g of crystalline ammonium chloride are separated off from the aqueous phase by evaporation.

Example 3

5 15.8 g of o-chloronitrobenzene are mixed with 30 g of liquid ammonia and 8 g of water in an autoclave made of acid-resistant steel. The autoclave is heated to 220 ° C. while shaking. The suspension of 80 mg of 5-strength palladium activated carbon catalyst in 20 g of water is introduced into the hydrogenation reactor according to Example 1. The hydrogen gas is employed, the temperature to 140 ⁰ C and the pressure adjusted to 100 bar and pushed the reaction mixture of amination in the hydrogenation reactor. After 40 minutes

Reaction time, the hydrogen supply is turned off Ammonia boiled, the catalyst warm from the reaction mixture filtered off and the filtrate extracted 5 times with 20 ml of benzene each time. By evaporation of the organic phase 10.2 g of o ~ phenylenediamine are obtained, which at 99 C melts.

Example 4

Starting from 1913 g of 2,5-dichloronitrobenzene, the aminated and hydrogenated as described in Example 3. Z-un 30 g of liquid ammonia and 8 g of water are aminated used. The amination is carried out at 200 ° C. and lasts 20 minutes. For hydrogenation, the suspension of 200 mg of 10% igera palladium activated carbon catalyst in 20 g Water used. The hydrogenation is carried out at 120 ° C and BO bar pressure and lasts 60 minutes. After removing the ammonia and filtering off the catalyst, the reaction mixture is extracted with 1,2-dichloroethene (3x20 ώΙ). Evaporation of the solvent gives 10.3 g of υ-phenylenediamine obtained that melts at 100 ° C. 10.1 g of ammonium chloride are obtained from the aqueous phase by evaporation.

Example 5

O-phenylenediamine is continuously produced in a device corresponding to the enclosed flow chart.

Using the metering pump 6, 1000 g of molten 2,5-dichloronitrobenzene are metered per hour, and using the metering pump 7 per hour 2300 g of 80% aqueous ammonium solution are metered into the tubular reactor of volume 2 dm, which is heated ^{to 200 ° C. in an oil bath.} The light emerging from the reactor mixture is cooled to 130 ⁰ C and printed in the hydrogenation reactor 11, the temperature of which is held by pressure water in the heating jacket at 130 C. The suspension of 8 g of 10% strength palladium activated carbon catalyst in 1100 ml of water is pressed into the reactor every hour by means of the metering pump 8.

The pressure in the reactor is 150 bar. The one from the separator 12 exiting liquid phase is in the heater 14 from

Ammonia freed. The catalyst will be on your filter 17 separated and used again. The o-phenylenedianine is from the warm, saturated aqueous solution in the continuous countercurrent extract with 1500 ml per hour extracted recirculated 1,2-trichloroethene. The product crystallizes, is separated on the filter 18 and air-dried. The device produces every hour 53Og o-phenylenediamine, which melts at 100 C. The watery one The ammonium chloride solution is collected in the container 19. 1 liter of solution is made by evaporation 280 g of crystalline ammonium chloride obtained.

Example 6

In the device according to Example 5 820 g of o-chloromitrobenzene, 2300 g of 80% ammonia solution, the suspension of 6 g prepared with 1100 ral water 5 # palladium activated carbon and 1500 ml of the in the circuit held Extraktxonsmittel 1,2-dich, lorethane fed in » The temperature in the amination reactor is 220 C, im Hydrogenation reactor 153 C at a pressure of 150 bar. on In the manner described in Example 5, 543 g of o-phenylenediamine, which melts at 101 ° C., are produced per hour.

The procedure has the following advantages:

- Instead of flammable solvents, aqueous Amccniak is used as the reaction medium.

- The ammonia, which is necessary anyway for the hydrogenolysis of the chlorine, ensures a suitable pH value and above in addition, the homogeneity of the reaction mixture.

- In the presence of ammonia, the hydrogenolysis of the chlorine produces ammonium chloride, i.e. a usable by-product, which does not pose any problems in terms of environmental protection.

- Beiß] Working according to the coupled procedure 13t it is superfluous, the starting compound of the general formula (I) from the reaction mixture of their preparation ^ u isolate and later dissolve again.

With the process according to the invention, the hydrogenation step, which was previously carried out discontinuously, can be advantageous continuously designed.

Claims (2)

FÜNER b R HIN G HOUSE f- I N (. I- PATFNTANWAtIt FUUOMtANnAlLNI Λ I 1 <Y Iv N I V N MAIVIAHU I WAI / Q A 3. MUNCHI N <IO SSE: I ^- OSIf-A (JH OS OI HO, D-HOOf) MUNCMI N ·>' ; ■ ». Apr i 1 1'iis Magyar Asvanyolaj es Koldg.u '. ΠΚΛΛ - .if. '¹; 7 O. (■ Kiserleti Intezet PROCESS FOR THE PRODUCTION OF ORTHO-PHENYLENEDIAMINE P a tentansprüche Process for the preparation of o-phonylenedianiine au ^ compounds the general formula 1 (7) (T) in which X is hydrogen or chlorine, by catalytic reduction with hydrogen or a hydrogen-containing gas, characterized in that the hydrogenation is carried out in the presence of 30-70t, expediently 40-50%, ammonia and 10- ^r > 0 "., expediently 30% -401, Waiser preferably carries out continuously, the solution v <n /.imnonirik ran, the catalyst, ilif i 11 ri <-rt and cl.ir; l'roduki ('lurch Υ-νΛ r .,)> Ι <- r en with a Lösurigrani tt <1 in \ <l / u <U'r by Kri st, i 1 1 i rj i eren, ibtretint. 2. The method according to claim 1, characterized. g e k e η π ζ e ι c h n e t that the compound of the general formula (I), wherein the meaning of X is the same as in claim 1, in which in their Preparation from compounds of the general formula (II) (ID where d.if Bi; i'lc> ut_ung of X is the same wit. · in claim 1,, infal (] fn Kciikt i.omigomisch, without- ν, νι i N (.- hi-nxi 'it 1: i ι: 1κ>! so! i crunq redu: '. i>: rt.