DE2313548C3 - N-N'-dichloro-terephthalic acid diamide and a process for the preparation of N, N'-dichloro-terephthalic acid diamide and N, N'-dichloro-isophthalic acid diamide - Google Patents

Description

It is known that lower aliphatic carboxamides can be halogenated in the molten state or in aqueous solution to give the corresponding N-haloamides. It is also known, saturated and unsaturated higher molecular weight N-chloro-fatty acid amides to produce more than 16 carbon atoms, by chlorine can in a corresponding, finely divided in water, water-insoluble fatty acid amides einwirker ¹ "(DT-PS 7 49 976, and DT-PS 8 78 491 ). It is also already known that aromatic carboxamides can be converted into the corresponding N-halogen compounds by chlorination or bromination. According to RL D a 11 a and T. Ghosh (Journ. Am. Chem. Soc, 35 [1913], p. 1044), N-chlorobenzamide is obtained in quantitative yield if it is immersed in the Ben2 'solution within several hours. oesäureamid introduces the stoichiometric amount of chlorine gas. Will . If chlorine is used in excess, the result is mainly N-dichlorobenzamide. According to the method of DT-PS 6 16 381 both aliphatic and aromatic N-chlorocarboxamides are prepared in such a way that a carboxamide in a non-dissolving liquid such. B. carbon tetrachloride or dichlorobenzene, and chlorine is passed into the suspension, which should advantageously contain a hydrochloric acid-binding agent. If these processes, known for monoamides, are transferred to aliphatic, alicyclic and arylaliphatic dicarboxylic acid halides, only low yields are generally obtained. According to the process of DT-PS 9 09 455, the yields can be improved if the halogenation is carried out in the presence of a hydrogen halide binding agent, eg. B. sodium bicarbonate, performs as a solvent, water, glacial acetic acid or another organic acid with the addition of

ίο Alkali or alkaline earth salts of these acids are used or the carboxamide dry mixes with the hydrogen halide binding agent and over the dry mixture conducts halogen vapors. However, was for the production of aromatic

N.N'-dihalocarboxylic acid camides so far no ge suitable method known. Only in US-PS 31 05 848 is the production of N, N'-dichloroisophthalic acid diamide by chlorination of isophthalic acid amide in nitrobenzene and in the presence of

also described sodium carbonate. When this known process is reworked, Ν, Ν'-dichloroisophthalic acid diamide is obtained in a yield of only 3.5% of theory. Th. The previously unknown N.N'-dichloroterephthalic acid amide can be obtained by this method

not manufacture at all. Also the processes known for the production of N-halogen monoamides do not achieve the goal: When chlorinating terephthalic acid amide in the presence of sodium or Potassium hydroxide only gives small amounts of the desired N.N'-dichloroterephthalic acid diamide. When using sodium carbonate or bicarbonate, no N-chlorine compound is obtained at all, but only larger amounts of terephthalic acid formed by saponification. The chlorination too in organic solvents does not bring the desired success. When using carbon tetrachloride or chlorobenzene, the terephthalic acid amide used is recovered quantitatively, if glacial acetic acid is used, the yield of N.N'-dichloroterephthalic acid diamide is only 2.3% of theory

The present invention relates to the new compound Ν, Ν'-dichloro-terephthalic acid diamide formula

CONHCl

CONHCl

and a process for the preparation of this compound and Ν, Ν'-dichloro-isophthalic acid diamide Chlorination of terephthalic acid diamide or isophthalic acid diamide. The procedure is characterized by that the chlorination in a dilute aqueous suspension of terephthalic acid diamide or of the isophthalic acid diamide is carried out at temperatures from 0 to 100 ° C, the dilution of the Reaction mixture is to be dimensioned so that by the end of the reaction, the resulting in the chlorination Hydrogen chloride remains almost completely dissolved in the reaction mixture.

It is surprising that the process of chlorination in a non-aqueous medium and using a hydrogen chloride

Tkzeptors, which leads to satisfactory yields in the case of the aliphatic, alicyclischcn and araliphatic mono- and dicarboxamides, in the case of the terephthalic acid diamide and the isophthalic acid diamide completely fails, on the other hand, the use of the aqueous mineral acid reaction medium, which amide, which in the case of aliphatic mono- and aralicarboxylic acids and alicyclic acid as well as aromatic monocarboxamides, e.g. B. with benzamide, either with low yields and / or long reaction times is associated, with terephthalic acid amide and isophthalic acid amide to success. This is all the more true as terephthalic acid amide and isophthalic acid amide, in contrast to benzamide, for example, are completely insoluble in an aqueous mineral acid medium. Also in view of the fact that the production of the already known N ₁ N-dibromoterephthalic acid diamide fails completely under the same conditions, i.e. by bromination in dilute aqueous hydrochloric or hydrobromic acid, the success of the process according to the invention must be described as extremely surprising.

As an aqueous mineral acid medium are such. B. dilute aqueous hydrochloric acid, sulfuric acid and Phosphoric acid.

A neutral aqueous suspension is preferably used in the process according to the invention the amides, the hydrogen chloride formed as a by-product in the chlorination being in the reaction mixture dissolves and the reaction thus takes place in a dilute aqueous hydrochloric acid medium. Preferred is also of dilute hydrochloric acid or dilute sulfuric acid aqueous suspensions of the Amides to go out.

The yield and rate of chlorination depend strongly on the acid concentration in the reaction mixture. Since the acid concentration of the reaction mixture in the course of the chlorination by free The rate of chlorination slows down as the hydrogen chloride increases Sales volume. If one of highly concentrated acids, z. B. from 50 weight percent If sulfuric acid or 25 percent strength by weight hydrochloric acid is used, only low yields are achieved. In concentrated hydrochloric or sulfuric acid, for example, no reaction takes place at all. When the acid concentration in the reaction mixture exceeds a certain value, the slows down Rapid turnover. This maximum acid concentration not to be exceeded is for each of the submitted Mineral acids specific, it also depends on the reaction temperature and the reaction pressure. It has been found that this is the case when the hydrogen chloride formed in the course of the chlorination can no longer be completely dissolved in the reaction mixture, d. H. if under reaction conditions the saturation concentration of hydrogen chloride in the reaction mixture would be exceeded. Since the Calculate the amount of hydrogen chloride released during the chlorination from the amount of amide used expediently, the dilution of the reaction mixture should already be adjusted accordingly when selecting the reaction medium. Of course the reaction mixture can also be used in the course of the reaction with water or a dilute mineral acid be diluted.

The chlorination of terephthalic acid amide and isophthalic acid amide is exothermic. The inventive The process is carried out at temperatures from 0 to 100 ° C. The application of higher Temperatures is disadvantageous in that, under these conditions, significant amounts due to hydrolysis Terephthalic acid or isophthalic acid are formed. Chlorination is preferred for economic reasons carried out at 0 to 60 ° C, the heat of reaction can be removed by water cooling. The method according to the invention can be used both at

ίο normal pressure as well as carried out at increased pressure will. With increasing pressure, the required reaction time decreases, the preferred pressure range however, for economic reasons, it is between 1 and 20 ata.

Since the chlorination takes place in the heterogeneous phase in the process according to the invention, thorough mixing of the suspension must be ensured. The dilution of the reaction mixture should at least be such that it can be stirred or otherwise mixed without difficulty. The preferred dilution of the reaction mixture is about 20 to 400 g of amide per liter of water or aqueous mineral acid.
If the process conditions mentioned are observed, the chlorination is complete after about 2 to 60 minutes. The amide is converted practically quantitatively into the Ν, Ν'-dichloramide without a solution occurring in the meantime. The suspension present after the chlorination is complete contains only the N.N'-dichloro-terephthalic acid amide or the Ν, Ν'-dichloro-isophthalic acid amide as a solid. The products can be used in the simplest manner, for. B. by filtering off or spinning off. After washing, e.g. B. with cold water, and drying at z. B. 7O ⁰ C in a vacuum you get them in the highest purity.

The N.N'-dichloroterephthalic acid amide according to the invention is a colorless microcrystalline substance that, when heated from 250 ° C, under lighter Gray touch sinters weakly and sublimates a little from 300 ° C. It is moderately soluble in polar organic Solvents, e.g. B. in dioxane, dimethylacetamide, dimethylformamide and hexamethylphosphoric triamide. N.N'-dichloro-terephthalic acid amide is in dark Containers practically indefinitely. It is a mild oxidizing agent at room temperature. Due to its excellent stability, it can e.g. B. advantageous as a replacement for the less stable antiseptic Sodium - N - chloro - ρ - toluenesulfonamide (Chloramine T) can be used.

N.N'-dichloroisophthalic acid amide and N, N'-dichloro-terephthalic acid amide are also valuable intermediate compounds. They can be converted into substituted ureas by reaction with amines, which are used as herbicides and pesticides.

example 1

540 g (3.29 mol) of terephthalic acid amide were suspended in 10 liters of water. Were in suspension 4 g of chlorine per minute were passed in for 2 hours with vigorous stirring. By low cooling was the reaction temperature was kept at 25 ° C. The pressure was 1.0 ata. After that, the reaction mixture became filtered, the residue washed with 2 liters of cold water and dried at 70 ° C in vacuo. 755 g (98.4% of theory) of colorless N, N'-dichloro-terephthalic acid diamide were obtained receive.

Example 2

32 g (0.195 mol) of terephthalic acid amide were in 0.6 liters of 17 weight percent hydrochloric acid suspended in a glass autoclave. At 6 ata were taking Stirring and cooling at 25 ° C. 33 g of chlorine were added. After 8 minutes there was a constant in the AutoVlav The pressure was stopped and the reaction was ended. The reaction mixture was worked up as in Example 1. The yield of pure N, N'-dichloroterephthalic acid diamide was 44.2 g (97.2% of theory).

Example 3

1200 g (7.317 mol) of terephthalic acid amide were suspended in 7 liters of 17% strength by weight hydrochloric acid. 1100 g of chlorine were fed into the suspension at 25 ° C. in the course of 30 minutes in such a way that the pressure was kept constant at 6 ata. Thereafter, the reaction mixture was as described in Example 1 Way worked up. The yield was 1690 g (99.1% of theory) of Ν, Ν'-dichloroterephthalic acid diamide.

Example 4

In a suspension of 400 g (2.439 mol) of terephthalic acid amide in 1 liter of 17 weight percent hydrochloric acid 360 g of chlorine were passed in under normal pressure at 55 ° C. over the course of 140 minutes. The work-up the reaction mixture is carried out as described in Example 1. The yield of N, N'-dichloroterephthalic acid diamide was 522 g (92% of theory).

Example 5

In a suspension of 5 g (0.0305 mol) Terephthalsäureamid in 200 ml of 10% aqueous sulfuric acid were introduced with stirring at atmospheric pressure and a temperature of 25 ⁰ C for 2 hours approximately 0.1 g chlorine per minute. The N, N'-dichloroterephthalic acid diamide was filtered off, washed with water and dried. The yield was 6.94 g (97.7% of theory).

Example 6

64 g (0.39 mol) of isophthalic acid amide were _{suspended in V 2} liters of 15% strength hydrochloric acid. With stirring, 90 g of gaseous chlorine were passed into the suspension at room temperature and normal pressure over the course of 3 hours. The reaction mixture was then filtered, and the residue was washed with cold water and dried. 90 g (99.0% of theory) Ν, Ν'-dichloro-isophthalsäurediamid of melting point 73.5 to 75 ⁰ C.

Example 7

16.4 g (0.10 mol) of terephthalic acid amide were suspended in 500 ml of 17 percent strength by weight hydrochloric acid and heated to 34 ° C in an enamel autoclave. Then using a dosing cuvette under intensive Stirring fed 22.8 g (0.32 mol) of liquid chlorine. A reaction temperature was established by water cooling Maintain 35 ° C. The reaction pressure was 10 ata.

After 5 minutes, the reaction suspension was rapidly expanded, discharged from the autoclave, filtered and washed with 200 ml of water. The residue was dried at 7O ⁰ C under vacuum. This resulted in 22.6 g (97% of theory) N.N'-dichlorotereohthalic acid diamide.

Example 8

16.4 g (0.10 mol) of terephthalic acid amide were suspended in 500 ml of 17% strength by weight hydrochloric acid

and heated ^{quickly to 45 °} C. in an enamel autoclave. Then 23 g (0.325 mol) of liquid chlorine were added by means of a metering cuvette with stirring and water cooling, the temperature rising to 55 ° C and the pressure to 20 ata within 30 seconds.

o rose. After 3 minutes the reaction mixture was discharged from the autoclave and filtered. The residue was washed with 200 ml of water and dried ^{at 70 ° C. in vacuo.} The yield was 94% of theory. Th.

The following comparative examples 9 to 13 show that when using the usual, for the preparation of aliphatic, alicyclic, araliphatic and aromatic N-chloro- or Ν, Ν'-dichlorocarboxamides suitable chlorination process in the production of Ν, Ν'-dichloro-terephthal- or N, N'-di chloro-isophthalic acid diamide fail.

Comparative example 9

8.2 g (50 mmol) of terephthalic acid amide were in

as a solution of 8.7 g (103 mmol) of sodium bicarbonate suspended in 450 ml of water. Under vigorous stirring were introduced within 30 minutes at 5 ⁰ C 7.1 g (100 mmol) of chlorine. A stormy development of carbon dioxide set in. When the reaction had ended (pH 7.5), the mixture was filtered and the residue was then suspended in dilute sodium hydroxide solution at 2 to 5 ° C., cooled to -5 ° C. and finally filtered using a glass frit. 6.23 g (38 mmol) of unreacted terephthalic acid amide remained as residue, corresponding to a conversion of 24% of theory. Th. The filtrate was then added dropwise to acetic acid at 0 ° C., whereby terephthalic acid precipitated out as a voluminous, white precipitate. It was washed with ice water and _{dried over P 2} O ₆ : 1.85 g (11 mmol). N, N'-dichloroterephthalic acid diamide was not obtained.

Comparative example 10

8.2 g (50 mmol) of terephthalic acid amide were
Suspended 400 ml of water at 5 ° C rapidly prepared with 26.5 g (250 mmol) of sodium carbonate in 500 ml of water and 7.1 g (100 mmol) of chlorine sodium hypochlorite solution are added The reaction mixture was stirred at four hours 1O ⁰ C vigorously . The pH was 10. Then unreacted terephthalic acid amide was filtered off: 5.69 g (34.7 mmol). The terephthalic acid amide conversion was accordingly 30.6%. The terephthalic acid formed by saponification was separated from the filtrate in the manner described in Example 9 by precipitation with acetic acid: 2.62 g (15.8 mmol), corresponding to 31.7% of theory. Th. Even with this procedure, no Ν, Ν'-dichloroterephthalic acid diamide was obtained.

Comparative Example 11

8.2 g of terephthalic acid amide (50 mmol) were suspended in 500 ml of water under nitrogen and slowly added with a solution freshly prepared from 20.0 g of NaOH (500 mmol), 400 ml of water and 7.1 g of Cl, (100 mmol) 5 ° C offset. The reaction mixture was then stirred vigorously for 4 hours at 10 ° C., then ^{cooled to -5 11} ° C. and filtered through a glass frit. the

white residue that was washed twice with cold water and dried, consisted of unreacted terephthalic acid amide (4.8 g; 29.4 mmol). Thus the conversion was 41.4% of theory. Th.

The filtrate was carefully poured into a solution of 50 ml of glacial acetic acid and 100 ml within 15 minutes Dripped in water at 0 to 7 ° C. A voluminous, cheesy precipitate fell out, which by means of a glass frit, washed well with ice water and then over phosphorus pentoxide at room temperature was dried. This crude product, 4.90 g of a light yellow powder, was dissolved in 50 ml of chloroform digested. After filtration, 1.61 g (10.9 mmol) of N, N'-dichloroterephthalic acid diamide were obtained as a residue receive. This corresponds to a yield of only 16.1% of theory. Th. With a selectivity of only 38.8%.

The previously unknown terephthalic acid bis-dichloramide crystallized in the form of the chloroform phase yellow needles. Yield: 3.29 g (25.3% of theory with 61.2% selectivity). This substance possesses opposite the Ν, Ν'-dichloro-terephthalsäuiediamid a reinforced Oxidizing effect and is characterized by good solubility in organic solvents, in particular Chlorinated hydrocarbons.

Comparative example 12

8.2 g (50 mmol) of terephthalic acid amide were suspended in 50 ml of water and at 0 to 5 ⁰ C within 30 minutes with stirring in a nitrogen atmosphere with a solution of 32.7 g of 86% (50OmMoI) potassium hydroxide, 7.10 g (100 mmol) of chlorine and 400 ml of water are added. The reaction mixture was stirred at the stated temperature for 5 hours. It became thinner and turned yellow-brown. The suspension was then filtered and worked up in the manner described in Example 11. 5.988 grams of terephthalic acid amide were recovered; the conversion was thus 2.21 g (13.5 mmol), this corresponds to 27% of theory. Th.

As in Example 11, 3.3 g of terephthalic acid bis-dichloramide (11 mmol; 22% yield) and 5% d. Th. Ν, Ν'-dichloroterephthalic acid diamide to be isolated.

Comparative example 13

41 g (0.25 mol) of terephthalic acid amide was mixed with 10.3 g (0.125 mol) of sieved zinc oxide in 300 ml of water suspended from 2 ° C, initiated within one and a half hours at 0 to 5 ° C 71 g (1.0 mol) of chlorine and then Stirred at 5 ° C. for 6 hours. After the filtration, the formed was N.N'-dichloroterephthalic acid amide separated from unreacted terephthalic acid amide with 2η sodium hydroxide solution at 5 ° C. and then precipitated in acetic acid and worked up analogously to Example 11. 35.2 grams (0.214 moles) of terephthalic acid amide were obtained recovered. The conversion was thus only 11.7% d. Th. The yield of N, N'-dichloroterephthalic acid diamide was 0.757 g (0.0325 mol) = 7.7% of theory. Th. 4% of the terephthalic acid amide became terephthalic acid saponified.

The following comparative examples 14 to 16 show that the chlorination of terephthalic acid amide in various organic solvents not at all or only with very low yields to give the N, N'-dichloro-terphthalic acid diamide i leads.

Comparative example 14

In a suspension of 41 g (0.25 mol) of terephthalic acid amide in 160 ml of glacial acetic acid were stirred vigorously within about 16 hours at 18 to 20 ° C Introduced 213.0 g (3.0MoI) of chlorine. The residue was then made of terephthalic acid amide and Ν, Ν'-dichloro-terephthalic acid amide filtered off and with Water washed. These two compounds were separated using dilute sodium hydroxide solution and subsequent precipitation with acetic acid. 39.9 g of unreacted terephthalic acid amide were recovered. The yield of Ν, Ν'-dichloroterephthalic acid diamide was 1.35 g (58 mmol), this corresponds to 2.3% of theory.

Comparative example 15

In a suspension of 41 g (0.25 mol) Terephthalsäureamid in 500 ml carbon tetrachloride, 265 g (3.74 mole) of chlorine is initiated were added with vigorous stirring over a period of 12 hours at 10 ⁰ C. The reaction mixture was worked up in the manner described in Example 13. The terephthalic acid amide was recovered quantitatively, the formation of N ₁ N'-dichloroterephthalic acid diamide could not be detected.

Comparative example 16

In a suspension of 41 g (0.25 mol) of terephthalic acid amide in 250 ml of chlorobenzene were vigorously Stirring initiated within 3.5 hours at boiling temperature (132 ° C) 121 g of chlorine. Sublimated about 5.4 g of colorless crystals. They turned out to be hexachlorobenzene, which by chlorination of the Solvent had arisen. The terephthalic acid amide used was recovered quantitatively. For comparison, it is shown that the known Ν, Ν'-dibromo-terephthalic acid amide when using the the procedure according to the invention is not obtainable at all:

16.4 g (100 mmol) Terephthalsäureamid were dissolved in 180 ml of 10% aqueous hydrobromic acid susspendicit and added dropwise at 20 ⁰ C with 32 g of bromine (200 mmol). The reaction mixture was then stirred for 24 hours and then nitrated. The residue was washed and dried. It consisted of 16.2 g of the terephthalic acid amide used.

16.4 g (100 mmol) of terephthalic acid amide were suspended in 180 ml of 10% strength aqueous hydrochloric acid and be 32 g of bromine were added dropwise at 20 ° C. After 5 hours, the reaction mixture was as in the case game 16 described worked up. The terephthalic acid amide was recovered quantitatively.

Claims (6)

Patent claims: 1. N.N'-dichloro-terephthalic acid diamide of the formula CONHCl CONHCl 2. Process for the preparation of N, N'-dichloroterephthalic acid diamide and of Ν, Ν'-dichloroisophthalic acid diamide by chlorination of terephthalic acid or isophthalic acid diamide, characterized in that the chlorination in one dilute mineral acid suspension of terephthalic acid or isophthalic acid diamide at temperatures carried out from 0 to 100 ° C, the dilution of the reaction mixture being carried out as follows measures that by the end of the reaction, the hydrogen chloride formed in the chlorination is almost complete remains completely dissolved in the reaction mixture. 3. The method according to claim 1, characterized in that that one starts from a neutral aqueous suspension. 4. The method according to claim 2, characterized in that one starts from a dilute hydrochloric acid or sulfuric acid suspension. 5. The method according to claim 2, characterized in that the chlorination is carried out at temperatures from O to 60 ⁰ C. 6. The method according to claim 2, characterized in that the chlorination under pressure from 1 to 20 ata.