SK277813B6 - Method of imines preparation - Google Patents

Abstract

Imines (azomethines, aldimines, ketimines) so-called Schiff's bases are prepared direct from aromatic nitro- or nitrosocompounds by acting of minimum one carbonyle compound, chosen from aromatic cycloalifatic or alifatic aldehydes and ketones and carbonaceous oxid at temperature 60 to 220 degrees of Celsius and pressure 0,3 to 30 MPa. Carbonylic condensation catalyzes system consisting of elementary sulfur or sulfur compound with molecular weight 34 to 98 gmol/exp -1/ (H/sub_2/S, COS, CS/sub_2/) in mass 0,1 to 10 per cent weight counted for nitrocompounds and nitrosocompounds. Next innorganic (NaOH, KOH, CH/sub_3/COONa, CH/sub_3/COOK, CH/sub_3/ONa,...) or organic aprotic nitrogeneous base (trialkylamines, pyridine, alkylpyridine) in mass 0,1 to 50 per cent weight and compound of bivalent to pentavalent vanadium in mass 0,001 to 3 per cent weight.

Description

Technical field

The invention relates to a process for the preparation of imines (azomethines, aldimines, ketimines), the so-called imines. Schiff bases, nitroaromatics or nitrosoaroinates and organic carbonyl compounds, in particular aromatic and cycloaliphatic aldehydes and ketones, catalyzed by carbonylation condensation with carbon monoxide.

BACKGROUND OF THE INVENTION

Imines (azometins, aldimines, ketimines) SchifT bases, used mainly as intermediates, have long been prepared by condensation of aldehydes as well as ketones with primary aliphatic, cycloaliphatic and aromatic amine (Deák G .: Minor Reactions in Organic Chemistry, p. 332, Alfa, Bratislava 1980, Schiff H .: Justus Liebigs Ann Chem 140, 1867, 93, 148, 1868, 330, 201, 1880, 355, 210, 1881, 114. Cordes FH, Jencks WP: J. Am Chem. Soc., 1962, p. 832). Aldehydes, in particular aromatic aldehydes and primary amines in an alkaline medium, form an aldimine (Schiff's base). In the first step of the reaction, an addition compound is formed from which iinine is formed by spontaneous elimination.

R RNH and R OH -H.0 R '= ₀ ___. \ ^Z ---- f \ - N - R '

H ^Z h 'k - HK ^Z

R

Thus, the effect of aromatic aldehydes on aniline with water separation results in anils or so-called anilines. Schichase bases (C ₁ H-NH 2 + O = CHC ₆ H ₅ - ₍ C 1 H ₅ NCHCl 3 + H +), in particular benzylidenenaniline, benzaldehyde, or benzaniline. Similarly, benzophenone and aniline produce benzophenoaniline (Reddelien G .: Ber. 42 4789 (1909), 43, 2476 (1910). Billman JH, Tai KM: J. Org. Chem. 23, 535 (1958). Weygand-Hildetag: Organisch-Chemische Experiinentierkunst, Russian translation: Eksperimenta in organičeskoj chimii, p. 470, Izd. Chemija, Moscow (1969), Kováč J., Kováč Š .: Organic Chemistry, p. 394, Alfa, Bratilslava 1977). The reaction proceeds at relatively low temperatures, but the azomethines formed are still only formed from an aromatic aldehyde and an aromatic primary amine of sufficient alkalinity. Schiff bases, prepared from aliphatic amines, have a C = N reactive bond and are capable of further reaction. Similarly, as well as azomethins, prepared from an aliphatic aldehyde and an aromatic amine, very easily, e.g. polymerize to form cyclic triamines and the like.

However, in spite of the technical simplicity of the methods for preparing imines from primary amines, the initial primary amines are difficult to access. This problem is solved by catalytic deoxygenation of organic compounds by carbon monoxide, direct synthesis of Schiff bases from aromatic nitroderivatives, aldehydes, resp. ketones and carbon monoxide, e.g. from nitrobenzene, benzaldehyde and carbon monoxide k * t4'.yz4Eor, 'bw -CHO' O ' ^{5 <1} °'

XT / —i ' ^{,: o} *

- B produces benzalaniline, at a temperature of 170 ° C, a pressure of 5 MPa under the catalytic action of noble metal compounds VO. groups, such as carbonyl rhodium and the interaction of pyridine (Igbal A.F.M .: J. Org. Chem. 37, 1972, p. 2791). However, the disadvantage is the difficult-to-reach catalyst and the need for high purity carbon monoxide.

SUMMARY OF THE INVENTION

The present invention relates to a process for the preparation of imines, the so-called imines. Schiff bases of aromatic nitro compounds and / or nitroso compounds containing one to two nitro- and / or nitroso groups per molecule by treatment with at least one organic carbonyl compound selected from aromatic cycloaliphatic and aliphatic aldehydes and ketones under a carbon monoxide pressure of 0.3 to 30 MPa, at 60 to 220'C, optionally in the presence of an aprotic solvent, carried out by condensing the catalyzed carbonylation catalyst system, comprising elemental sulfur and / or sulfur compounds with a molar mass of 34-98 grnoľ ¹ in an amount of 0.1 to 10% by weight . %, based on the weight of the nitro compound and / or the nitroso compound, further an inorganic and / or organic base in an amount of 0.1 to 50 wt. and / or divalent to pentavalent vanadium compounds in an amount of 0.001 to 3% by weight.

The inorganic base is selected from alkali metal hydroxides, in particular sodium hydroxide, potassium and lithium hydroxides, or their precursors such as sodium oxide, potassium oxide. Furthermore, alkali metal alkoxides, in particular sodium methoxide to sodium pentoxide, potassium methoxide to pentoxide, or precursors thereof, such as alkali metals together with aliphatic alcohols C 1 -C 8. Subsequently, the alkali salts of weak carboxylic acids, such as sodium acetate to sodium valenate, potassium acetate to potassium valenate, and mixtures of sodium salts of carboxylic acids and C ₂ -C ₆ hydroxyl acids, resulting from the production of cyclohexanone and cyclohexanol by oxidation of cyclohexane or fatty acids by oxidation of paraffins.

The organic bases consist of organic aprotic nitrogen compounds with at least one tert, nitrogen per molecule, in particular trialkylamines with alkyls having a carbon number of 1 to 5, then dimethylcyclohexylamine. Heterocyclic compounds are, in particular, pyridine, methylpyridines, dimethylpyridines, methylethylpiridines and the like.

The catalyst system component is either elemental sulfur and / or low molecular weight sulfur compounds, in particular carbonyl sulfide, hydrogen sulfide, methanethiol, dimethyl sulfide, carbon disulfide. Ammonium sulfide is also suitable. Less suitable but useful is hydrogen sulphide and sodium sulphide, which is also a donor of an inorganic base.

Of the divalent to pentavalent vanadium compounds, most suitable are those soluble in the reaction medium, such as ammonium metavanadate, vanadium sulfide, vanadium oxychloride, and the like.

An advantage of the process according to the invention is a one-step process for producing Schiff bases, without pre-reducing the aromatic nitro compounds to the primary carbon monoxide, characterized in Example 1, to a pressure of 10 MPa. Thereafter, the contents of the autoclave are heated to 150 [deg.] C. and maintained at this temperature to within ± 2 [deg.] C. with constant stirring for 5 h, the main reaction being as follows:

ôH ♦ s c ». »<Q ™> —φτ θ

The conversion of 2,4-dinitrotoulene is practically 100% and the selectivity to the diimine is 64.9%.

Example 12

50 g of nitrosobenzene, 50 g of benzene, 100 g of benzaldehyde, 5 g of trimethylamine, 0.1 g of vanadium sulphide, 0.3 g of ammonium sulphide and 0.3 g of hydrogen sulphide are not weighed into the autoclave specified in Example 1. Finally, syngas containing 49.3 vol. carbon monoxide, 39,9% hydrogen, 4,3% vol. methane, 0.07% v / v carbonyl sulfide, 0.27% v / v oxygen, 2.43% v / v of carbon dioxide and 3.7% vol. nitrogen up to 15 MPa. Thereafter, the contents of the autoclave are heated to 140 [deg.] C. under constant rotation and maintained at this temperature to within ± 2 [deg.] C. for 5 hours.

with alkyls having 1 to 5 carbons and / or heterocyclic nitrogen compounds, preferably pyridine.

End of document

Industrial usability

Iinins, in particular aldimines, but also ketimines, are useful as intermediates for the production of technical auxiliaries, in particular corrosion inhibitors, antioxidants, pesticides, polymer additives, etc., and can be easily manufactured in the chemical industry, since starting materials, especially nitroaromatics are available in a wider range than aromatic amines. In addition, it is possible to use carbon monoxide-containing exhaust gases.

Claims (3)

PATENT CLAIMS A process for the preparation of imines from aromatic nitro compounds and / or nitroso compounds containing one to two nitro and / or nitroso groups per molecule by treatment with at least one organic carbonyl compound selected from aromatic, cycloaliphatic and aliphatic aldehydes and ketones at a carbon monoxide pressure of 0.3 to carbon monoxide 30 psi, at 60 to 220 ° C, optionally in the presence of an aprotic solvent, characterized in that the coupling catalyzed carbonylation catalyst system, comprising elemental sulfur and / or sulfur compounds with a molar mass of up to 98 g mol 34 ¹ at 0.1 %, based on the weight of the nitro compound and / or the nitroso compound, the inorganic and / or organic base, in an amount of 0.1 to 50% by weight; and / or a divalent to five-year-old vanadium compound in an amount of 0.001 to 3% by weight. The process according to claim 1, characterized in that the inorganic base is selected from alkali metal hydroxides, alkali metal alkoxides and weak carboxylic acid alkali salts, preferably alkali metal alkoxides. 3. The process according to claim 1, wherein the organic base is a nitrogen-containing base with tertiary nitrogen selected from trialkylamines. 276 amines, ie directly from aromatic nitro compounds or nitroso compounds and the possibility of recovering available, even exhaled, carbon monoxide-containing gas sources, without the technically complex preparation and refining. Even the admixtures of carbonyl sulfide and hydrogen sulfide contained in carbon monoxide at least partially substitute the need for the deliberate addition of sulfur or a low molecular weight sulfur compound as a component of the catalytic carbonylation condensation system. Last but not least, the technical raw material and economic availability of components of the catalytic system, its high efficiency, easy regenerability and insensitivity to catalytic poisons. The process according to the invention, in which virtually all aromatic nitro- and nitroso compounds containing at least one nitro- or nitroso compound in the molecule, even more than two groups, if safety reasons so permit, can be used in addition to carbon monoxide as the starting compound. polynitro, respectively. polynitrózozlúčenín. Of the aldehydes, the best yields are obtained with aromatic and cycloaliphatic aldehydes. Significantly lower selectivity to Schiff bases is achieved with aliphatic aldehydes. The process can be carried out continuously, semi-continuously and discontinuously. Further data on the implementation of the method of production of so-called. The Schiff bases of the invention as well as other advantages are apparent from the examples. DETAILED DESCRIPTION OF THE INVENTION Example 1 Weigh 100 g of nitrobenzene, 100 g of benzaldehyde, 10 g of triethylamine with 0.54 wt% addition to a 500 euros non-stainless steel rotary (240 ipm) autoclave. water, 0.1 g ammonium metavanadate. After the autoclave was closed, 1 g of hydrogen sulphide and carbon monoxide were added at a rate of 1.4% by volume. of hydrogen, 0.1 vol. of oxygen and 0,6% vol. nitrogen, up to a pressure of 12 MPa. Thereafter, the contents of the autoclave are heated to 150 ° C with constant rotation and maintained at ± 2 ° C for 4 h. During this time, 0.732 moles of nitrobenzene and 0.46 moles of benzaldehyde are reacted and 0.43 moles of iinine are identified. (azomethine), in particular benzalaniline (benzylidenenaniline), i. j. nitrobenzene conversion was 92.8%, benzaldehyde 48.8%, and Sclúff base selectivity 58.1%. Example 2 50 g of nitrobenzene are weighed into the autoclave specified in Example 1, yielding 0.027% lunotine. water, 100 g benzaldehyde, 10 g triethylamine, 0.1 g ammonium metavanadate and after autoclaving 1 g hydrogen sulfide. The initial pressure of carbon monoxide, as described in Example 1, is 13 MPa. The reaction temperature was 150 ± 2 ° C and 4 h. After cooling the autoclave to room temperature, it reached 9 MPa. The Schiff base is isolated. The melting point of the isolated benzalaniline is 48.6 ° C. Conversion of nitrobenzene reaches 98.6%, benzaldehyde 71.3% and selectivity to benzalaniline (benzylidenenaniline) reaches 74.6%. Example 3 The procedure is similar to that of Example 2, except that instead of nitrobenzene (50 g) other nitroaromatics are examined in the same weight, 100 g of benzaldehyde, 10 g of triethylamine, 0.1 g of ammonium metavanadate and initial pressure of oxide are used in all experiments. The carbon monoxide at room temperature is 13 MPa. The results of isochronous experiments (4 h) depending on the nitroaromatic species, especially nitroaromatic conversion and selectivity to the corresponding imines, are summarized in Tab. Table 1. conversion Selektlvít « Pccžl'.v oitroArotMt ni'.rotremiLu no answer Schi- <V, ffovv OiiU  r. > <V ♦ n! r.rctfí] UEN 97.5 3 ?. 3 \ rccciuen 98.1 and ».; 4-chloro-1-nitrobenzene 79.3 73 6 «-EtoKV-l-nltrebenzén 34.? 76.6 Example 4 50 g of nitrobenzene, 100 g of acetaldehyde, 10 g of triethylamine, 0.1 g of ammonium metavanadate, 1 g of hydrogen sulphide are weighed into the autoclave of Example 1 and carbon monoxide is introduced at room temperature to a pressure of 10 MPa. The reaction temperature is 140 ± 2 ° C and the reaction time is 4 h. The nitrobenzene conversion reaches 100%, but the selectivity to aldimine is only 49.3%, which is obviously the result of a considerable course of side and subsequent reactions. Example 5 The procedure is analogous to Example 4, except that 3 g of elemental sulfur is weighed in place of hydrogen sulphide. Nitrobenzene conversion reached 98.5% and Schiff base selectivity only 56.4%. Example 6 The procedure is analogous to Example 2 except that 1 g of sodium ethoxide and 1 g of potassium acetate are used instead of 10 g of triethylamine as a component of the catalyst system. Nitrobenzene conversion was 99.4% and benzylidenaniline selectivity 87.9%. Example 7 The procedure is analogous to Example 2 except that 1.3 g of carbonyl sulphide is used instead of 1 g of hydrogen sulphide and 0.1 g of vanadium sulphide is used instead of ammonium metavanadate. Nitrobenzene conversion reached 99% and benzalaniline selectivity 89.9%. Example 8 50 g of nitrobenzene, 100 g of benzophenone, 1 g of sodium methoxide, 1 g of potassium hydroxide, 2 g of pyridine and 0.1 g of vanadium pentoxide are weighed into the autoclave specified in Example 1. After closing the autoclave, 1 g of carbonyl sulphide and 1 g of carbon disulphide are added and the carbon monoxide is brought to a pressure of 12 MPa. The reaction temperature is 164 ± 3 &quot; C and 4 hours. The nitrobenzene conversion reaches 97.3% and the selectivity to benzophenonanil 89.6%. Example 9 The procedure is similar to Example 2 except that the temperature of the carbonylation reaction is 90 ± 2 ° C. Nitrobenzene conversion in 4 h. reaches 67.3% and in 6 hours. 98.5%, with a selectivity to benzalaniline of 92.3%. Example 10 The procedure is analogous to Example 2 except that only 0.4 g is used instead of 1 g of hydrogen sulfide. The pressure drop time is increased from 75 min. The conversion of nitrobenzene reaches 97.5% and the selectivity to benzalaniline increases to 84.8%. Example 11 50 g of toluene, 25 g of 2,4-dinitrotoulene, 100 g of benzaldehyde, 6 g of triisobutylamine, 0.01 g of vanadium hydroxide and 0.02 g of vanadium sulphide are weighed into the autoclave specified in Example 1. After the autoclave was closed, 1 g of hydrogen sulfide was added and introduced