SK277836B6 - Method of carbonyl reduction of aromatic nitrocompound and/or nitroaminocompounds - Google Patents

Abstract

Carbonyl reduction of aromatic nitrocompounds to nitroaminocompounds or aminocompounds, and also reduction of nitrocompounds to aromatic aminocompounds, is realised by presence of water by gas containing the carbon monooxide at temperature 50 to 300 degrees of Celsius and pressure 0,1 to 30 MPa by catalytic effect of two to threecomponent catalytic system. Necessary component is sulphur or sulphur compound as hydrogen sulfide, carbonylsulfide and hydrogen sulfide, carbonylsulfide and another necessert component is basic surroundings created by presence of ammonium or at least one of primary to tertiary alkylamines with number C atoms in alkyl 1 to 8 or cyclohexylamine and alkyl cyclohexylamines. Subsidiary component (promoter) is compound of vanadium.

Description

Technical field

The invention relates to a process for the carbonylation reduction of aromatic nitro compounds selectively, either to the corresponding aminonitrile or amino compounds, and to aminonitro compounds to amino compounds, by treatment with carbon monoxide.

BACKGROUND OF THE INVENTION

To date, reduction with metals and metal compounds such as sodium, aluminum, magnesium, tin, iron, metal hydrides, but also non-metal compounds such as hydrazine, phenylhydrazine, phosphorus and sulfur compounds is known. Thus, sulfur itself has reducing abilities, as well as hydrogen sulfide, sulfides, hydrostatics and polysulfides / Hudlický M., Trojánek J .: Preparative reactions in organic chemistry, Volume I, Reduction and Oxidation, p. 73 - 84,166 173, Prague, Czechoslovak Academy of Sciences Publishing House (1953): cit. Zinin N .: Ann. 44, 283 (1842)]. Thus, aromatic nitro compounds can be converted by careful reduction of sulfides or hydrosimics to hydroxylamines and at higher temperatures to amines. The disadvantage, however, is the need for above-stoichiometric amounts of sulfur, respectively. sulfur compounds as reducing agents, and thereafter considerable technical problems in removing large amounts of sulfur compounds from the reaction products.

Even less effective are reductions with alcohols, formaldehyde, formic acid, hydroiodic acid, and are therefore virtually unusable to reduce organic nitro compounds to amines. Electro-reductions are energy-intensive.

Conventional industrial catalytic processes for the hydrogenation of nitrobenzene to aniline on copper-containing or copper-nickel catalysts, in addition to evident advantages, are, however, energy-intensive and unsuitable for the hydrogenation of temperature labile nitro compounds. In addition, they require pure hydrogen.

Of interest is hydrogenation catalysed by pentacyanidone cobalt, where in aqueous and aqueous-alcoholic environments, even at room temperature, nitrobenzene and azobenzene / US Pat. 3,205,217, Kwiatok J. et al .: J. Am. Chem. Soc. 84, 304 (1962)], a mixture of azo and hydrazo compounds from nitrobenzene and o-nitrophenol (Kwiatok J. et al .: Adv. Chem. Ser. 37, 201 (1963)] and a mixture of amine and azo compound at elevated hydrogen pressure. More active and selective sulfur are platinum and palladium base catalysts on which nitrobenzene is hydrogenated to aniline with a selectivity of 98% / Nazarova NM et al .: Izv. AN USSR, ser. chim. 1981, p. 1 500 /. 2,4-Dinitrotoulene / Gostikin VP and others are hydrogenated on the Raneynicl liquid phase catalyst. exam. textbooks. introduced, Khimija i chim. technology, tom 3, off. 7, 53 (1990)]. However, the processes require highly pure hydrogen and catalyst regeneration is technically difficult. However, catalytic reduction of nitroaromatics with synthesis gas to the corresponding aromatic amines under the catalytic action of cobalt carbonyl, rhodium or tutorial is also known (Takesada H. et al .: Bull. Chem. Soc. Japan 43, 2 192 (1990); Murabashi et al. : ibid 33, 78 (1960), Cenini S. et al .: Chem Commun., 1983, p.186 /, and carbon monoxide in the presence of water, such as PhNOj + 3CO + H ₂ O -> PhNHj + 3CO ₂ / Watanabe Y. et al .: Tetrahedron, Lett., 24, 4, 121 (1983), Bull Chem. Soc., Jap., 57, 2867 (1984), Kaneda K. et al .: J. Mol. 12, 385 (1981)] However, the drawback is the technically difficult to obtain catalyst system, sensitivity to catalytic poisons and its difficult regeneration, and it is not surprising that indirect methods for the preparation of amines, such as aromatic amides, by reaction with tetraalkylammonium polyhalide (Jap). No. 02 268 141 (Nov. 1, 1990)], which, however, are resource-intensive and energy-intensive.

These problems are partially solved by the process for the preparation of primary aromatic amines by catalytic reductive carbonylation of nitro compounds with carbon monoxide and water according to U.S. Pat. AO 274 049. However, the disadvantage is the multicomponentity of the catalytic system and its lower efficiency, which requires greater component consumption. In addition, the products contain inorganic compounds which are difficult to remove both technically and ecologically.

SUMMARY OF THE INVENTION

Principle of a process for the carbonylation reduction of aromatic nitro compounds and / or nitroamino compounds to nitroamino and / or aromatic diamino compounds in an alkaline environment by treatment with a carbon monoxide gas at a pressure of from 1 to 30 MPa and a temperature of 50 to 300 ° C %, consisting of sulfur and / or at least one sulfur compound, in an amount of 0.01 to 10% by weight, calculated on the organic nitro compound and / or the nitroamino compound, according to the invention is carried out in the presence of at least one aliphatic and / or cycloaliphatic base and / or ammonia, in an amount of 1 to 200 wt.%, calculated on the nitro and / or nitroamino compounds, and water in an amount of 10 to 300 wt.%, calculated on the starting nitro and nitroamino compounds.

In addition, a solvent, preferably inert under the conditions mentioned, such as alcohols, dialkyl ethers, dioxane, acetals and the like, preferably those which are at least partially dissolved in water and at least partially dissolving the organic components present in the reaction system, may be present in the reaction medium. Interfacial transfer catalysts may be a suitable additive, since in the reaction system there is water next to each other and rarely water-insoluble organic compounds.

Organic bases include, in addition to aliphatic, cycloaliphatic and alkylcycloaliphatic amines in the process of the invention. Most preferred are alkylamines having alkyls of 1 to 8, such as monoalkylamines, dialkylamines, and especially trialkylamines, such as trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamines. Then alkanolamines, in particular triethanolamine, optionally monoethanolamine and diethanolamine, tripropanolamine and the like. Further cycloalkylamines and alkylcycloamines, in particular cyclohexylamine, dicyclohexylamine, ethylcyclohexylamine. Aromatic amines such as aniline, benzylamine, dibenzylamine and the like are useful, but in particular because of their poor alkalinity and hence low efficiency or isolation from the reaction products.

A particularly suitable basic component is ammonia, whether applied as a gaseous or in the form of an aqueous solution, which is also considered to be aqueous ammonium hydroxide according to the invention. Further, they may be precursors of ammonia, i.e. compounds which decompose under reductive carbonylation conditions to form ammonia or ammonium hydroxide, such as urea, hexamethylenetetraamine and ammonium carbonate.

Of the sulfur compounds, low molecular weight compounds, especially hydrogen sulfide, are carbonyl sulfide. Other sulfur compounds as well as elemental sulfur are useful but less effective.

A necessary component in the reaction system is a carbon monoxide-containing gas such as pure carbon monoxide, synthesis gas, water gas, methane gas, gudrons, and the like, and it is not necessary to remove hydrogen sulfide, carbonyl sulfide and other sulfur compounds from such gases. Moreover, at a sufficient concentration, there is no need to separately supply hydrogen sulfide, carbonyl sulfide, or other sulfur compounds to the reaction medium. Never mind the presence of hydrogen, methane, carbon dioxide. However, due to their lower carbon monoxide partial pressure, the reaction rate should be lower if their content is high. Another necessary ingredient is water, which is added either as a component of the raw materials or separately. At less than 1%, the selectivity to amines is low, but at greater than 200%, which is also useful according to the invention, the reaction space is already technically ineffective.

An advantage of the process according to the invention is the practical absence of salt-forming substances in the reaction system and in the product, a surprising synergistic effect of hydrogen sulfide with ammonia and in particular organic bases as a component of the catalytic system. In contrast to the combination of hydrogen sulphide with alkali metal salts of carboxylic acids, alkoxides or alkali metal hydroxides. This makes it possible to minimize, e.g. with elemental sulfur to even reduce the sulfur compound content in the catalytic system. A considerable advantage is mostly the relatively good solubility of organic bases and ammonia both in water and in reduced nitro compounds and their technically simple regeneration. Last but not least, in the case of di- and polynitro compounds, selectively reduce only some or all of the nitro groups to amino groups.

The process according to the invention can be carried out continuously, semi-continuously or continuously. Further advantages as well as advantages of the method are evident from the examples.

DETAILED DESCRIPTION OF THE INVENTION

Example 1

30 g of m-dinitrobenzene (1,3-dinitrobenzene), 50 g of methanol, 50 g of distilled water, 5 g of diethylamine and 0.1 g are weighed into a rotary (180 rpm) stainless steel autoclave of 1 dm ^3. ammonium metavanadate NH4VO3. After the autoclave was closed, 0.7 g of hydrogen sulphide was added and carbon monoxide with 0.2% v / v added. oxygen and 1.8% hydrogen up to 13 MPa. Thereafter, the contents of the autoclave are heated to 150 ± 2 ° C at a constant rotation of the autoclave at which the pressure in the autoclave is 18.3 MPa and maintained at this temperature for 3 h. During this time the total pressure in the autoclave will drop to 17 MPa. The autoclave is then cooled, and the unconverted gas is discharged to a field burner. The contents of the autoclave are removed, weighed and analyzed. The conversion of m-dinitrobenzene is 94.6% and the selectivity to m-phenylenediamine is 81.3%. The remainder of the selectivity is mainly selectivity to m-nitroaniline. Diethylformamide is also present.

Example 2

The procedure is analogous to Example 1, except that the vanadium compound NH 4 VO 3 is omitted from the batch into the autoclave. The conversion of m-dinitrobenzene is 58.2%, the selectivity to m-nitroaniline is 99.3% and m-phenylenediamine is only 0.1%.

Example 3

50 g of nitrobenzene, 5 g of elemental powder sieve, 40 g of distilled water, 0.1 g of NH4VO3 and 100 g of a 10% by weight aqueous ammonium hydroxide solution were weighed into the autoclave specified in Example 1. After the autoclave was closed, the oxide was introduced into it. carbon monoxide, also specified in Example 1, to a pressure of 13 MPa. To this end, the contents of the autoclave are heated to 150 ± 2 < 0 > C with constant rotation and maintained at this temperature for 1 h. The autoclave is then cooled, the gas is vented and the liquid content is weighed and analyzed. Nitrobenzene conversion reached 100%, aniline selectivity 95%, methyl N-phenylcarbamate selectivity 0.5%. The remainder to 100% is selectivity to urea and other compounds.

Example 4

Weigh 30 grams of p-nitroaniline, 40.5 grams of methanol, 50.5 grams of distilled water, 0.1 grams of NH4VO3 and 2 grams into a 0.5 dm ³ stainless steel rotary autoclave. triethylamine. After the autoclave was closed, 0.7 g of hydrogen sulphide and carbon monoxide were introduced into the autoclave at a pressure of 12.7 MPa. To this end, the contents of the autoclave are heated to 150 ± 2 ° C with constant rotation and maintained at this temperature for 1 hour. The autoclave is then cooled, the residual gas is vented and the product obtained is weighed, analyzed and isolated. The conversion of p-nitroaniline is complete and the selectivity to p-phenylenediamine is also 100%.

Example 5

15 g of m-dinitrobenzene, 15 g of water, 20 g of methanol, 1 g of diethylamine and 0.5 g of carbon disulphide are weighed into the autoclave described in Example 4. After the autoclave is closed, carbon monoxide is introduced into it at a pressure of 12 MPa. The carbonylation reduction is carried out at a temperature of 150 ± 2'C for 3 h. The conversion of m-dinitrobenzene reaches 62.2%, the selectivity to m-phenylenediamine 1.8% and to m-nitroaniline 92.7%.

Example 6

100 g of nitrobenzene with an admixture of 0.24% by weight are weighed into a 1 dm ³ autoclave characterized in Example 1. water, followed by 100 g of monoethanolamine, 100 g of water, and after the autoclave was closed, 0.7 g of hydrogen sulphide and carbon monoxide up to 14 MPa were fed into it. Thereafter, the contents of the autoclave are heated to 150 ± 2 ° C and held at this temperature for 4 h with continuous rotation. For this purpose, the autoclave is cooled, the unconverted gas is discharged and the liquid product is weighed, analyzed and isolated. Nitrobenzene conversion reaches 92.1%, aniline selectivity reaches only 28.6%, the remainder being mainly N-2-hydroxyethylamino-N'-phenylurea selectivity, with some of the monoethanolamine reacting to 2-hydroxyethylformamide HOCH2CH2NHCOH.

Example 7

The procedure is analogous to Example 6, except that 104 g of water is added instead of 100 g of water and 0.1 g of ammonium metavanadate is added. Nitrobenzene conversion reached 90.3% and aniline selectivity 52.3%.

Example 8

100 g of nitrobenzene, 100 g of methanol, 50 g of distilled water, 20 g of aqueous ammonium hydroxide solution having a concentration of 25% by weight are weighed into a liter autoclave as described in Example 1. and 0.1 g of ammonium metavanadate. After the autoclave was closed, 0.7 g of hydrogen sulphide and carbon monoxide were introduced to a pressure of 12.3 MPa. Then, with constant rotation, the autoclave was heated to 120 ± 2 ° C and held at this temperature for 1 h. For this, the autoclave was cooled to room temperature, gas evolved, and the liquid product was weighed, analyzed and separated. The nitrobenzene conversion was 100%, the aniline selectivity was 97.4% and the methyl-N-phenylurethane 0.5%.

Example 9

The procedure is similar to Example 8 except that the reaction temperature is 150 ± 3 ° C. nitrobenzene conversion reached 100%, aniline selectivity 99.1% and methyl-N-phenylurethane 0.4%.

In another experiment under similar conditions, the conversion of nitrobenzene was also 100%, the selectivity to aniline 98.0% and to methyl N-phenylcarbamate 0.3%.

Example 10

Weigh 1 g of 2-nitropropane, 1 g of water, 1 g of methanol, 0.01 g of vanadium pentoxide and 1 g of aqueous ammonium hydroxide solution at a concentration of 25% by weight in a 10 cm ^{@ 1} pressure cuvette. 05 g hydrogen sulphide and carbon monoxide up to 10 MPa. The actual carbonylation reduction is carried out with constant rotation of the cuvette at 130 ± 2 ° C for 4 h. The conversion of 2-nitropropane reached 99.8% and the selectivity to 2-aminopropane was 93 J%.

Example 11

50 g of 1-nitronaphthalene, 100 g of methanol, 0.1 g of vanadium pentoxide, 50 g of water and 20 g of a 25% strength aqueous ammonium hydroxide solution are weighed into a liter autoclave as described in Example 1. After the autoclave was closed, 0.9 g of hydrogen sulphide and carbon monoxide, as specified in Example 1, were passed to a pressure of 10 MPa. To this end, the contents of the autoclave are heated to 150 ± 2 ^e C with constant rotation and maintained at this temperature for 4 h. The conversion of 1-nitronaphthalene is 99.1% and the selectivity to the corresponding naphthylamine is 98.7%.

Example 12

The procedure is analogous to Example 11, except that 1.1 g of carbonyl sulphide, instead of 50 g to 70 g of water and instead of 20 g of aqueous ammonium hydroxide solution are introduced with 15 g of ethylcyclohexylamine instead of 0.9 g of hydrogen sulfide. The conversion of 1-nitronaphthalene reaches 100% and the selectivity to naphthylamine is 99.2%.

Example 13

101.5 g of nitrobenzene, 100 g of methanol, 50.5 g of distilled water, 0.1 g of NH2VO and 20 g of a 25% by weight aqueous ammonium hydroxide solution are weighed into a 1 dm ³ autoclave. After the autoclave was closed, 0.7 g of hydrogen sulphide and carbon monoxide were passed to a pressure of 11.9 MPa. The carbonylation reduction is carried out for 4 h. at 90 ± PC. Nitrobenzene conversion reached 81.6%, aniline selectivity 96.5% and methyl N-phenylcarbamate 0.8%.

industry, especially in the production of aromatic mono-polyamines for the production of dyes, monomers, anti-corrosive agents and the like, from the corresponding nitroaromatics. It also makes it possible to recover raw carbon monoxide and even chemically unused flue gas fumes, also containing carbon monoxide.

Claims (6)

PATENT CLAIMS A process for the carbonylation reduction of aromatic nitro compounds and / or nitroamino compounds to nitroamino and / or aromatic diamino compounds in an alkaline environment by treating a carbon monoxide gas at a pressure of 0.1 to 30 MPa and a temperature of 50 to 300 ° C, with water and catalytic action. % of a system consisting of sulfur and / or at least one sulfur compound in an amount of 0.01 to 10 wt. calculated on organic nitro and / or nitroamino compounds or mixtures of sulfur and / or mixtures of at least one sulfur compound with at least one vanadium compound, optionally in the presence of solvents, characterized in that the reaction is carried out in the presence of at least one aliphatic and / or cycloaliphatic base and / % of ammonia, in an amount of 1 to 200 wt.%, calculated on the nitro and / or nitroamino compounds, and water in an amount of 10 to 300 wt.%, calculated on the starting nitro and nitroamino compounds. Process according to claim 1, characterized in that an interfacial transfer catalyst is additionally present in the reaction medium. Process according to claims 1 and 2, characterized in that the aliphatic bases are monoalkylamines to trialkylamines with alkyls having a carbon number of 1 to 8, preferably soluble in both water and reduced compounds. Process according to claims 1 to 3, characterized in that the cycloaliphatic bases form primary and secondary cycloaliphatic, preferably cyclohexylamine and / or alkylcycloaliphatic bases, preferably ethylcyclohexylamine. The process according to claims 1 to 4, characterized in that the aliphatic bases form alkanolamines having a carbon number of 2 to 9, preferably monoethanolamine and triethanolamine. Method according to claims 1 to 5, characterized in that the applied sulfur compound is a low molecular weight sulfur compound, preferably hydrogen sulfide.