AU673458B2

AU673458B2 - Process for the preparation of secondary or tertiary amines

Info

Publication number: AU673458B2
Application number: AU74322/94A
Authority: AU
Inventors: Gerhard Diekhaus; Detlef Kampmann; Claus Kniep; Thomas Muller; Jutta Walter; Jurgen Weber
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1993-10-13
Filing date: 1994-09-30
Publication date: 1996-11-07
Anticipated expiration: 2014-09-30
Also published as: EP0648736B1; ES2107722T3; TW262459B; JP2662504B2; DE59403716D1; DE4334809A1; JPH07165679A; ATE156802T1; EP0648736A1; CA2133801A1; AU7432294A

Abstract

The invention relates to a process for the preparation of secondary or tertiary amines by reaction of higher olefins with carbon monoxide, hydrogen and a primary or secondary amine. The reaction takes place in the presence of a mixture of rhodium and ruthenium compounds, which are homogeneously dissolved in the reaction mixture, as catalyst.

Description

I/uu/U11 2(2u 1 Rogulation 3.2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT e a Application Number: Lodged: ro o r r r Invention Title: PROCESS FOR THE PREPARATION OF SECONDARY OR TERTIARY

AMINES

The following statement is a full description of this invention, including the best method of performing it known to us Process for the preparation of secondary. or tertiary amines The invention relates to a process for the preparation of secondary or tertiary amines by catalytic reaction of higher terminal olefins with carbon monoxide, hydrogen and a primary or secondary amine. The reaction is carried out under pressure at elevated temperature in the presence of a mixture of rhodium compounds and ruthenium compounds as the catalyst.

The preparation of secondary or tertiary amines from olefins, carbon monoxide, hydrogen and primary or secondary amines, this reaction being called aminomethylation, is known. The reaction is carried out in the presence of catalysts, among which iron-pentacarbonyl and compounds 15 of rhodium, ruthenium or iridium have the greatest i importance. Instead of hydrogen, water can also be employed as a reactant (cf. F. Jachimowicz, J. W. Raksis, J. Org. Chem. 1982, 47, pages 445 to 447). According to a process described in GB-A-2 113 310, tertiary amines are obtained by reaction of long-chain olefins with carbon monoxide, hydrogen and a primary or secondary amine in the presence of a rhodium compound or ruthenium compound as the catalyst, this compound being dissolved in a mono-, di- or trialcohol or a mixture of one of these alcohols with water. When the reaction has ended, the reaction product and solvent phase are separated from one another and the solvent containing the catalyst is recycled to the reaction zone. Re-use of the catalyst is associated with a reduction in the amine yield and increased formation of by-products. The catalyst is therefore operational to only a limited extent and must be worked up or regenerated for recovery, especially of the valuable rhodium.

Secondary and tertiary amines are important as precursors of compounds which are employed as surfactants. For this field of use, it is of interest to control the reaction of the terminal olefins with carbon monoxide, hydrogen 2 and primary or secondary amines in respect of the formation of tertiary n-amine and iso-amine. The ratio of the two isomers in the reaction mixture in fact determines the properties of the surfactants prepared from them.

The object was therefore to develop a highly active catalyst for the aminomethylaticn of higher terminal olefins which is active in such a small amount that its recycling is not necessary, and if appropriate its recovery can even be dispensed with.

Furthermore, the catalyst should allow the ratio of nand iso-compound in the reaction product to be varied as desired.

The invention relates to a process for the preparation of secondary or tertiary amines from terminal olefins having 15 at least 6 carbon atoms in the molecule, carbon monoxide, hydrogen and a primary or secondary amine at elevated temperature under increased pressure in the presence of a mixture of rhodium compounds and ruthenium compounds, dissolved homogeneously in the reaction mixture, as the catalyst. It comprises employing rhodium and ruthenium in a molar ratio of 1:2 to 1:50, the rhodium concentration being 2 to 15 ppm by weight based on the olefin.

'Surprisingly, the mixture of rhodium compound and ruthenium compound is an extremely active aminomethylation catalyst which is active even at a low rhodium concentration, based on the olefin employed, so that it does not have to be recycled or recovered.

To achieve yields of more than 85 in particular more than 90 based on the olefin employed, a rhodium concentration (based on the olefin) of 2 to 15 ppm by weight should be maintained. Higher or lower concentration reduce the yield. Rhodium contents, based on the olefin, of 6 to 12, and in particular 8 to 10 ppm are 1 preferred.

3 The catalytic.activity of the rhodium is intensified by the combination of rhodium with ruthenium. Furthermore, by adjusting the molar ratio of rhodium and ruthenium, the ratio of n- an(, iso-compound in the reaction product can be influenced. According to the invention, 2 to mol of ruthenium are employed per mole of rhodium, and 3 to 30, and in particular 4 to 15 mol of ruthenium per mole of rhodium are preferred.

The molar ratio of the metals in the catalyst to be chosen in an individual case to achieve a certain ratio of n-amine and iso-amine in the reaction product depends on the rhodium concentration. Concentrations at the lower and at the upper limit of the range of 2 to 15 ppm by weight of rhodium characteristic for the process accord- S 15 ing to the invention result in amine mixtures which predominantly comprise the n-isomer at molar ratios of rhodium to ruthenium of about 1:3 to about 1:6. In the case of catalysts which are richer in ruthe ium and comprise about 10 to 20 mol of ruthenium per mole of rhodium, approximately equimolar mixtures of n- and isocompound are formed.

Olefins having more than 6 carbon atoms in the molecule, in particular having 6 to 24, and preferably 8 to carbon atoms, are reacted by the process according to the 25 invention. The olefins can be straight-chain or mono- or polybranched. Their double bond is on a terminal carbon atom. Examples of suitable olefins are n-hex-1-ene, n-hept-1-ene, n-oct-1-ene, n-non-1-ene, n-dec-1-ene, n-dodec-1-ene, n-tetradec-1-ene and n-hexadec-1-ene, in particular n-dec-l-ene, n-dodec-1-ene and n-tetradec-1-ene.

The primary or secondary amines used as reaction partners of the olefins correspond to the general formula R'R 2

NH,

in which R 1 and R 2 are identical or different and are hydrogen or alkyl radicals having 1 to 4 carbon atoms, KZ, with the proviso that the radicals R

I

and R" are not 4 simultaneously H. Examples of suitable primary amines, which can be employed in commercially available form, are methylamine, ethylamine and propylamine, in particular methylamine and ethylamine, and examples of secondary amines are dimethylamine, diethylamine and methylethylamine. 1 to 3, in particular 1 to 2 and preferably 1 to mol of primary or .secondary amine are used per mole of olefin.

Th composition of the synthesis gas, i.e. the ratio of carbon monoxide to hydrogen, can be varied within wide limits. In general, the gas mixture comprises carbon monoxide and hydrogen in a volume ratio of about 1:1 to about 1:2.5, but mixtures of a different composition are also suitable. 1 to 12, in particular 1.2 to 15 preferably 1.5 to 8 mol of carbon monoxide and 2 to 24, in particular 2.4 to 20 and preferably 3 to 16 mol of hydrogen are used per mole of olefin. It has proved appropriate to carry out the reaction with an excess of to 200, in particular 25 to 120 mol of carbon monoxide 20 and 20 to 400, in particular 50 to 200 mol of hydrogen per mole of olefin.

It is particularly expedient to react the reaction partners olefin and amine with the carbon monoxide/hydrogen mixture in the absence of solvents or 25 other reaction media. In this reaction procedure, the amine can be isolated by simple separation of the aqueous and organic (product) phase. If the individual circumstances require, however, it is also possible to carry out the reaction of the reactants in the presence of a solvent. Suitable solvents are alcohols, preferably mnonoalcohols having 1 to 3 and dialcohols having 3 to 6 carbon atoms in the molecule.

Rhodium and ruthenium are catalytically active in the form of the carbonyl compounds which form in the reaction mixture under the reaction conditions. Catalyst precursors which are employed are the metals in the 5 finely divided state or as compounds which are soluble or insoluble in the reaction system, for example salts of organic or inorganic acids, such as the nitrates, formates, acetates or 2-ethylhexanoates, or else the oxides.

Instead of preparing' the catalyst in the reaction mixture, it can be preformed from the metals or the compounds listed above as examples in an auxiliary medium and added as a solution to the reaction mixture.

The reaction of the reactants is carried out at temperatures from 100 to 1600, in particular 110 to 1500 and preferably 120 to 140 0 C. The pressure is 4 to 20, in particular 8 to 18 and preferably 10 to 16 MPa. The reaction is carried out in customary pressure reactors 15 which are provided with stirring or mixing equipment, for example stirred autoclaves. The catalyst is initially introduced into the reactor in the form of its components as a suspension or solution together with the olefin, amine and solvent, and carbon monoxide and hydrogen are 20 passed into the mixture. The residence time of the reaction partners in the reaction zone is 2 to 6, in particular 3 to 5 h.

The reaction can be carried out either batchwise or continuously.

When the reaction has ended, the reaction mixture can be cooled, if necessary, and is separated by distillation.

The process according to the invention is illustrated in more detail in the following examples, but is not limited to the embodiments described.

Example 1 (Comparison) 169 g of 1-dodecene (1 mol), 200 g of isopropanol, as the solvent, and 50 ppm by weight of ruthenium (in the form 6 of ruthenium 'acetylacetonate) are initially introduced into a 1 1 autoclave with an up-and-down stirrer. 60 g of dimethylamine (1.33 mol) are fed to the reaction mixture with the aid of synthesis gas (CO/H 2 1:1) until a pressr of 7.5 MPa is reached, and a temperature of 150 0 C i_1, with synthesis gas (CO/H 2 1:1) a reaction pressure of 15 MPa are finally established. After hours, no further uptake of gas is observed. The mixture is allowed to cool and is let down, and the crude product is removed quantitatively and analyzed by gas chromatography. The result can be seen from the following table.

Example 2 (Comparison) The procedure is as in Example 1, with the exception that 15 instead of ruthenium, rhodium is employed as the catalyst in the form of rhodium 2-ethylhexanoate. The catalyst concentration is 3 ppm by weight of rhodium, based on the olefin employed. The results can be seen from the table.

Example 3 (Comparison) 20 The procedure is as in Example 1, but twice the amount of ruthenium, i.e. 100 ppm by weight, based on the olefin employed, is used. The results can be seen from the table.

S

Example 4 (Comparison) The procedure is as in Example 1, but rhodium is employed as the catalyst in the form of rhodium 2-ethylhexanoate in a concentration of 6 ppm by weight of rhodium, based on the olefin. The results can be seen from the table.

Example The procedure is as in Example 1, but using a mixed catalyst of 50 ppm by weight of ruthenium (in the form of 7 ruthenium acetylacetonate) and 3 ppm by weight of rhodium, (in the form of rhodium 2-ethylhexanoate). The results can be seen from the table.

Example 6 The procedure is as in Example 1, but using a mixed catalyst of 100 ppm by weight of ruthenium (in the form of ruthenium acetylacetonate) and 10 ppm by weight of rhodium (in the form of rhodium 2-ethylhexanoate). The results can be seen from the table.

Example 7 The procedure is as in Example 1, but using a mixed catalyst of 58.6 ppm by weight of ruthenium (as ruthenium acetylacetonate) and 11.7 ppm by weight of rhodium (as rhodium 2-ethylhexanoate), in each case based on the olefin. The results can be seen from the table.

Example 8 The procedure is as in Example 1, but using a mixed catalyst of 5.9 ppm by weight of rhodium (as rhodium 2-ethylhexanoate) and 58.6 ppm by weight of ruthenium (as ruthenium acetylacetonate), in each case based on the olefin. The results can be seen from the table.

Example 9 (Coyorsoco The procedure is as in Example 1, but using a mixed catalyst of 100 ppm by weight of ruthenium (as ruthenium acetylacetonate) and 1.7 ppm by weight of rhodium (as rhodium 2-ethylhexanoate), in each case based on the olefin. The results can be seen from the table.

f yv 0 0 0 Tab! e Examnne No. 1 2 3 4 5 6 8 9 Catalyst [Ru(III) acetylacetonate]: ppm of ruthenium [based on the 1-dodecene employed] Catalyst [Rhodium 2-Eli]: ppm of rhodium based on the 1-dodecene employed] GC analysis[% First runnings C12-EC range Intermediate runnings N,N1-DH-i-C13-amines Intermediate runnings +n-C13-ol N1,1-DM-n-C13-amines Intermediate runnings C15/C26 ranges elutable after-runnings Conversion[% Selectivity Yield 50 0 100 0 50 100 58.6 58.6 0 3 0 6 10 11.7 5.9 1.7 0.38 26.65 0.70 26.95 0.31 44.18 0.38 29.08 0.32 33.62 0.16 3.63 0.71 18.46 0.80 31.53 0.36 46.90 0.30 0.63 0.39 0.19 0.56 2.75 20.96 0.11 33.44 1 3.68 2.34 0.75 46.55 0.53 47.25 2.41 0.80 50.05 0.36 44.0 1.31 0.81 45.87 0.50 48.78 4.06 0.82 47.56 0.49 44.20 22.43 1.07 32.64 0.54 38.50 2.07 77.57 91.71 71.14 0.83 32.81 1.24 41.41 1.95 1.99 2.54 2.31 73.35 70.92 81.54 79.04 97.66 97.59 98.69 95.94 96.97 52.52 96.19 46.96 96.051 96.37 95.91 95.64 71.13 37.25 78.43 37.12 93.80 94.05 94.65 91.76

Claims

1. A process for the preparation of secondary or tertiary amine from a terminal olefin having at least 6 carbon atoms in the molecule, carbon monoxide, hydrogen and primary or secondary amines at elevated temperature under increased pressure in the presence of a mixture of rhodium compounds and ruthenium compounds, dissolved homogeneously in the reaction mixture, as the catalyst, which comprises employing rhodium and ruthenium in a molar ratio of 1:2 to 1:50, the rhodium concentration being 2 to 15 ppm by weight based on the olefin.

2. A process as claimed in claim 1, wherein the rhodium concentration, based on the olefin, is 6 to 12, in particular 8 to 10 ppm by weight.

3. A process as claimed in claim 1 or 2, wherein 3 to 30, in particular 4 to 15 mol of ruthenium are employed per mole of rhodium.

4. A process as claimed in any one of claims 1 to 3, wherein the reaction is carried out in the presence of a solvent.

5. A process as claimed in claim 4, wherein a monoalcohol having 1 to 3 or dialcohol having 3 to 6 carbon atoms in the molecule is used as the solvent.

6. A process as claimed in any one of claims 1 to 5, wherein the reaction is carried out at 100 to 1600C, and under pressure of 4 to 20 MPa.

7 A process as claimed in any one of claims 1 to 5 wherein the reaction is carried out at 110 to 1500C.

8. A process as claimed in any of claims 1 to 5 wherein the reaction is carried out at 120 to 1400C. 7 (9/ i- L

9. A process as claimed in any one of claims 1 to 5 and 7 to 8 wherein the reaction is carried out at 8 to 18 MPa.

A process as claimed in any one of claims 1 to 5 and 7 to 8 wherein the reaction is carried out at 10 to 16 MPa.

11. A process as claimed in any one of claims 1 to 10, wherein the olefin is straight-chain or mono- or polybranched and contains 6 to 24 carbon atoms in the molecule.

12. A process as claimed in any one of claims 1-10, wherein the olefin is straight-chain or mono- or polybranched and contains 8 to 20 carbon atoms in the molecule.

13. A process as claimed in any one of claims 1 to 12, wherein the amine corresponds to the formula R1R2NH, in which R1 and R2 are identical or different and are hydrogen or alkyl radicals having 1 to 4 carbon atoms, with the proviso that R1 and R2 are not simultaneously hydrogen.

14. A process as claimed in any one of claims 1 to 13, wherein 1 to 3 mol of primary or secondary amine are employed per mole of olefin. i:

15. A process as claimed in any one of claims 1 to 13, wherein 1 to 2 mol of primary or secondary amine are employed per mole of olefin.

16. A process as claimed in any one of claims 1 to 13, wherein 1 to 01.5 mol of primary or secondary amine are employed per mole of olefin. DATED this 6th day of September, 1996 HOECHST AKTIENGESELLSCHAFT WATERMARK PATENT TRADEMARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA AU7432294.WPC[DOC. 008] KJS:EK r v i' Z Abstract The invention relates to a, process for the preparation of secondary or tertiary amines by reaction of higher olefins with carbon monoxide, hydrogen and a primary or secondary amine. The reaction is carried out in the presence of a mixture 6f rhodium compounds and ruthenium compounds, which are dissolved homogeneously in the reaction mixture, as the catalyst. «o o• 0 0**0