CS200448B1 - Method of production by diphenylamines - Google Patents

Abstract

The invention a* relates to the production of diphenylamine by heating aniline in the presence of a modified catalyst based on inorganic compounds containing fluorine and phosphorus. These compounds contain fluorine and phosphorus, and add to aniline in the amount of 0.1 to 6 wt. as fluorine-ammonium phosphates, or as phosphoric oxide in the amount of 0.1 to 8% of the water, calculated on dioxygenated aniline and/or trihydrophosphoric acid alone or in the form of alcohol and aniline, in a mixture with at least one substance from the group of anilinium fluoride, ammonium fluoride, calcium ammonium fluoride and hydrofluoric acid, whereby the reaction is carried out in a closed system, and preferably periodic or continuous removal of ammonia from the reaction chamber.

Description

The invention relates to a process for the production of diphenylamine by heating aniline in the presence of a mixed catalyst based on inorganic compounds containing fluorine and phosphorus. These compounds contain fluorine and phosphorus, and are added to aniline in an amount of 0.1 to 6 wt. as ammonium fluorophosphates, or as phosphorus pentoxide in an amount of 0.1 to 8 wt. %, calculated on the aniline and/or trihydrophosphoric acid alone or in the form of a mixture of aniline and aniline, in a mixture with at least one substance from the group of anilinium fluoride, ammonium fluoride, ammonium fluoride and hydrofluoric acid, the reaction being carried out in a closed system, and preferably with periodic or continuous removal of ammonia from the reaction vessel.

200,448

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The invention relates to a method for producing diphenylamine by heating aniline in the presence of a tolerable catalyst based on inorganic compounds containing fluorine and phosphorus.

In new processes for the production of diphenylamine from aniline, catalysts are mostly substances containing boron and fluorine in their molecule, e.g. a complex of aniline or ammonia with boron trifluoride (NSR Pat. No. 1,116,231). According to this, at 100 °C without removing ammonia from the reaction system, 20% of the conversion of aniline to diphenylamine was achieved in 8 hours. According to the Salčí process, diphenylamine is prepared from aniline by condensation in the presence of ammonium tetrafluoroborate, boron trifluoride and its complexes (USA Pat. No. 3,071,619). The disadvantage of this process is the limitation of the catalyst in the reaction system, which entails significant technological complications. Another process for preparing diphenylamine from aniline uses as catalysts substances of the formula R ₍ 0H) _2BP2 , where R means ammonium or anilinium, and also compounds of the type RjRgOÍBF^)^, where R, and Rg mean ammonium or anilinium, or R ₁ means anilinium and Rg is modified ammonium (NSR Pat. No. 2,503,660). The disadvantage of using the catalyst R^gOÍBF^)^ lies in the preparation of the compound of the formula. NSR Pat. Description No. 2 521 293 uses as a catalyst for the reaction of preparing diphenylamine from aniline substances containing boron and fluorine in their molecule in an atomic ratio of 1 : 2 to 1 : 4. According to this procedure (NSR patent description No. 2 521 293), for example, the reaction was carried out at a temperature of 330 °C so that 0.77 wt. of ammonium tetrafluoroborate and 0.38 wt. of water were used for the aniline used. The ammonia formed was removed during the reaction and after 5 hours the content of diphenylamine in the reaction mixture was 27 wt. If tetrafluoroboric acid was used, prepared from hydrofluoric acid and boric acid in an amount of 1 wt., calculated as boron trifluoride, then by adding 1 wt. of water, while the mixture was stirred at a temperature of 330 °C, after 3 hours 20.5 wt. of diphenylamine was added to the reaction mixture.

The latest process for preparing diphenylamine from aniline (USSR patent No. 547 224) uses aluminum chloride with an admixture of ammonium tetrafluoroborate in an amount of 8 to 21 wt. % as a catalyst. If the charged catalyst was used in the indicated ratio, higher conversions of aniline to diphenylamine were achieved than when the individual components of the catalyst mixture were used in a pure state. The corrosion of the production equipment treated with aluminum chloride remains a questionable issue for this catalyst.

The above disadvantages are eliminated by the method of producing diformylamine by heating aniline to a temperature of 27°C to 400°C under a pressure of 1.0 to 3.3 MPa, and in the presence of a modified catalyst based on inorganic compounds according to the invention, the essence of which is that to aniline, fluorine and phosphorus-containing compounds are added fluorophosphoric acids in an amount of 0.1 to 6 parts by weight, calculated on the starting aniline, or phosphorus pentoxide and/or trihydrophosphoric acid, alone or in the form of a salt with aniline, in a mixture with at least one substance from the group of aniline fluoride, amine fluoride, acid fluoride and hydrofluoric acid, in an amount of 0.1 to 8 parts by weight, calculated on the starting aniline, while the process is carried out in a reverse system, advantage of periodic or «mAi.su» removal* of emwulekw in the reaction system.

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The advantage of the process according to this invention is the good solubility of anilinium fluoride in aniline at temperatures from 30 to 100 °C, as well as the good solubility of trihydrophosphoric acid and phosphorus pentoxide in a mixture of aniline and anilinium fluoride up to the boiling point of aniline, which facilitates technological application for water.

The starting material for the production of diphenylamine is aniline, which can be of various purity, most often of common commercial quality. Substances based on inorganic compounds containing fluorine and phosphorus in the molecule are used as catalysts. These are ammonium fluorophosphates, such as ammonium difluorophosphate or diammonium and/or diammonium monofluorophosphate. As salts of trihydrophosphoric acid with aniline, monoanilinium phosphate and/or dianilinium phosphate are added.

The term closed system in the process according to the invention is understood to mean a reaction apparatus of a conventional type which can be closed off from the surrounding space during the process, whereby the pressure in the closed system also increases as a result of the rising temperature. Normal technological losses caused by leakage or deliberate intervention, such as the removal of ammonia by discharge, do not affect the interpretation of the term.

The process is favorably affected by the removal of ammonia, which shifts the equilibrium for the formation of the final product in a favorable direction. The process can be run as continuous or discontinuous, or even semi-continuous, without significantly affecting the requirements for the ratio of the starting material and the catalyst. The working pressure in a closed system is a value resulting from the concentration of individual components of the reaction mixture and the working temperature, while by removing a component, for example ammonia, it can be influenced within a certain range.

The following examples of embodiments illustrate the subject matter of the invention in more detail, but do not limit it in any way. They also indicate further advantages.

Example 1

The described production of diphenylamine from aniline is carried out in a Rotomag 100 type autoclave equipped with a 250 ml pressure vessel, an electric resistance heating element with automatic temperature control with an accuracy of - 1 °C, a device for sampling, temperature and pressure measurement and equipped with a magnetic stirrer. The ammonia formed during the reaction is not removed.

To 100 g of aniline (1.073 mol) is added 1.135 β (9.54.10 ^-3 mol) of ammonium difluorophosphate. The autoclave is heated first to a temperature of 170 °C, at which any water from the reaction system is removed, and then to a reaction temperature of 340 °C, at which the reaction takes place for 4 hours. Samples are taken at specified Sas intervals and the diphenylamine content is determined by gas chromatography.

The results are always given in weight percentages, based on the reaction product.

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Roakfin time (*) 2 4 Diphenylanine content by mass.) 21.5 27.8 Pressure (MPa) 3.08 3.35 Example 2 To the starting aniline batch as in example 1, 1.278 g is added (9.54.10 ^-3 mole) nonofluorophophorophine diammonium. At a temperature of 300 °C the following results are obtained: Roakfin time Diphenylanine content Pressure (h) (^ wt.) (MPa) 2 8.7 1.78 4 11.5 2.01 Example 3 To the starting aniline batch as in example 1, 0.621 g is added (1.088 . 10 ² moles) and 0.935 β (2.885 . 1θ ² zero) 100% trihydrophosphoric acid, at reaction

temperature· 340 °C o* certain lead content of diphenylamine in the reaction mixture:

Roakfin time Diphenylanine content Pressure (H) (56 wt.) (MPa) 2 19.4 3.0 4 24.2 3.3

Example 4

To the starting aniline batch as in Example 1, 0.706 g (1.906 . 10” ² mol) of anion fluoride and the same amount of trihydrophosphoric acid as in Example 3 are added. At a reaction temperature of 320 °C, the following results are expected:

Reaction time Diphenylamine content Pressure (h) (weight) (MPa)

14.5 2.4

18.2 2.7

Example 5

To a batch of the desired aniline as in Example 1, 0.544 g (9.54 . io" ³ mol) of anionic acid fluoride and 0.677 g (4.769 · to" ³ mol) of phosphorous oxide are added. At a temperature of 340 °C, the following results are obtained!

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Reaction time Content of dif anylamine Pressure (h) (7> matter.) (MPa) 2 25.1 3.07 b 32.5 3.28 Example 6 To the starting aniline as in example 1 aa adds tollco fluoride aaéaaeho as in example 4 and as much phosphorus cyanide as in example 5 . At a temperature of 340 *0 aa grinds the maltose content of diphenylamine v reaction mmoait Reaction time Diphenylamine content Pressure (fa) (% wt.) (MPa) 2 21.1 2.6 4 28.5 2.75 Example 7 To 99.42 g (1.067 mol) of starting aniline vyhrlatefao na · temperature 70 *0 aa add 0.87 g (7.689 .io" ³ mol) of aniline fluoride, after dissolving and adding a small amount of acid ny trihydrophoaphoračnaj as in example 3, then aa mas wins aa the temperature at which aa achieves complete dissolution of the individual components in aniliaa and doses them into the autoclave. At a reaction temperature of 340 ° and the following results are obtained1 Response time Diphenylamine content Pressure (fa) mass) (MP*) 2 23.5 2.95 4 25.1 3.2

Example 8

To 98.5 β (1.057 ·όΐ) of aniline aniline, add 2.157 β (0.019 μl) of anthline fluoride and heat the mixture at a temperature of 80 °C, while the aa does not completely dissolve the 1 in. Phosphorus oxide completely dissolved and aaaa aa washed in an autoclave. At a reaction temperature of 340 °C, the following content of difaylamine in the reaction mixture was obtained.

Reaction time Content diphenyl awlnn Pressure (fa) (1· wt.) (MPa) 2 19.3 2.37 4 24.8 2.78

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Example 9

To the batch of starting aniline and catalyst components as in Example 5, 0.257 g (1.43 · IO ^-2 mol) of water is added. At a temperature of 330 °C, the following results are obtained:

Reaction time Diphenylamine content Pressure (h) (% wt.) (MPa)

16.4 2.72

21.2 3.10

Example 10

To 100 β aniline (1.073 mol) is added 0.567 β (4.77 10 ^- ^ mol) of diammonium difluorophosphate. At a temperature of 320 °C the following content of diphenylamine in the reaction mixture is determined:

Reaction time Diphenylamine content Pressure (h) (% wt.) (MPa)

15.8 2.3

20.4 2.5

Example 11

To 98 g of aniline (1.0523 mol) was added 2.71 g (9.53 10"^ mol) of dianilinium phosphoroate. The mixture was heated to 80 °C, the solution was filtered and charged into an autoclave, where 0.98 g (1.91 . 10** ² mol) of a 39% aqueous solution of hydrofluoric acid was added. At a reaction temperature of 315 °C, the following results were obtained:

Reaction time Obeah diphenylamine Pressure (h) (% wt) (MPa)

15.6 2.6

19.7 2.8

Example 12

To 99.1 g (1.0642 mol) of aniline ea are added 1.822 β (9.53 10~-* mol) of monoaniliniumphosphorane and hydrofluoric acid. At a reaction temperature of 300 °C, the following results are obtained:

Reaction time

Diphenylamine content (M) (% wt.) 9.0 ii.9

Pressure (MPa)

1.9

2.1

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Example 13

To 99>33 e (1(0665 mol) of aniline aa are added 0.283 β (2.383 . 1θ”^ mol) of ammonium difluorophosphate and 0.319 β (2.383 . 10~^ mol) of diammonium monofluorophosphate and 0.455 « (2.383 . W ³ mol) of monoanilinium phosphate and 0.677 β (2.383 . 10~ ³ mol) of dianilinium phosphate and hydrofluoric acid as in Example 11. At a temperature of 330 °C the following results are obtained»

Reaction time Diphenylamine content Pressure (h) (% wt.) (MPa)

From 16.8 2.58

21.5 3.08

Claims (2)

1. A process for the production of a diphosphate laminate by heating an aluminum cable at a temperature of 270 to 400 ° C and a pressure of 1.0 to 3.5 MPa, and in the presence of a supported catalyst based on inorganic compounds containing fluorine and phosphorus, characterized in that to the aniline as fluorine and phosphorus-containing compounds add ammonium fluorophosphates in an amount of 0.1 to 6% by weight, based on the starting aniline or phosphorus pentoxide and / or trihydrophosphoric acid, alone or in the form of a salt and aniline, mixed with at least one substance from the group of anilinium fluoride, ammonium fluoride, acid ammonium fluoride and hydrofluoric acid in an amount of 0.1 to 8% by weight, calculated on the starting aniline, wherein the reaction is carried out in a closed system, preferably with periodic or continuous removal of ammonia from the annual system . 2. The process according to claim 1, characterized in that monoaniline phosphate and / or palm oil are added as salts of trihydrophosphoric acid and aniline.