KR810000579B1 - Process for preparation of catalyst - Google Patents

Abstract

A Rh catalyst RhxCo(PR3)x; R =aryl or alkyl group such as methyl, buthyl and phenyl, X = H or halogen, X = integer 2,3 is manufd. An organic potassium compd. dissolved in an absolute alcohol is mixed and heated, and then a Rh compd. dissolved in 40 - 50≰C absolute alcohol is added and C1-4 aldehyde and alkali metal such as Na or Ka, which is dissolved in the absolute alcohol, are added at high velocity, mixed vigorously and recirculated.

Description

Method for producing rhodium catalyst

The present invention relates to a method for producing a rhodium catalyst containing various organophosphorus compounds as ligands.

The rhodium catalyst of the present invention is used to hydroformyl an olefin to make the corresponding aldehyde, and has the structure of the following general formula (I).

RhXCO (PR ₃ ) x... … (I)

Wherein R is alkyl and aryl groups such as methyl, butyl and phenyl,

X is hydrogen or halogen and X is an integer from 2 to 3.

In particular, the catalyst of the general formula (I) is widely used as a catalyst for the hydroformylation reaction for producing octanol from propylene.

Recently, many methods have been developed for the hydrogenation of olefins, carbonyl compounds, aromatic compounds or the hydroformylation and hydrocarboxylation of olefins by using complexes of rhodium compounds and organophosphorus compounds as soluble catalysts in homogeneous catalysis.

Cobalt compounds, such as cobalt octacarbonyl, have been used as conventional catalysts for hydroformylating olefins to make the corresponding aldehydes. However, in the case of using these cobalt compounds, the hydroformylation reaction conditions of the olefin, for example, the reaction pressure and the reaction temperature must be very violent, and the production rate of n-aldehyde and isoaldehyde is low, resulting in a desired yield of n-aldehyde. Has this low drawback.

In order to eliminate the above-mentioned drawbacks, the rhodium catalyst of the present invention can be used to increase the desired yield of n-aldehyde under very mild reaction conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In detail, the organic phosphorus compound used as a ligand is dissolved in anhydrous alcohol solution, stirred and heated, and then a rhodium compound dissolved in hot anhydrous alcohol at 40-50 ° C. is added to the aldehyde, which is a carbonyl donor group. Alkali metals such as sodium and potassium are dissolved in anhydrous alcohol, added, and vigorously stirred and refluxed to remove the rhodium catalyst of the general formula (I).

What should be noted in the preparation of the rhodium catalyst of the present invention is to stir vigorously while rapidly adding each compound continuously while maintaining the homogeneous reaction conditions until the production reaction is completed to complete the reaction.

If this is not done well, the unreacted product will contaminate the desired product, resulting in lower yield of the final product.

Rhodium compounds used in the present invention include metal rhodium, rhodium chloride, rhodium acetate, rhodium nitrate, and the like, and rhodium chloride is preferably used.

In addition, organophosphorus compounds used as ligands include PR ₃ (where R is as defined above) and the like.

The carbonyl group donor of the rhodium catalyst is an aldehyde having 1 to 4 carbon atoms, preferably formaldehyde.

In addition, when a rhodium metal compound is used in the production reaction, hydrazine and sodium borohydride have been used as a reducing agent in the past, but this production process is inconvenient due to the two-step production reaction and the production yield is relatively low as about 80%.

However, by using an alkali metal, for example, an alloy of sodium, potassium or potassium-sodium as the reducing agent and an anhydrous alcohol solution, the manufacturing process is simple and a yield of 90% or more can be obtained by a one-step reaction.

In the preparation of the rhodium catalyst of the present invention, the ligand is coexisted in excess of the stoichiometric amount necessary for complex formation with the metal for reasons such as increased stability of the catalyst and improved performance of the catalyst. Generally, the metal rhodium and the ligand are in a molar ratio of about 1: 5 to 1: 100, preferably about 1:10.

The reaction temperature is generally 80 to 100 ° C.

The present invention is described in detail with reference to the following examples.

Example 1

Three holes equipped with a reflux condenser and nitrogen injector were placed in a 500 ml round bottom flask in a 500 ml heater and placed on a magnetic stirrer. 100 ml of anhydrous ethanol and 2.62 g (1.0 mmol) of triphenylphosphine were added to a flask filled with nitrogen through a nitrogen inleter, heated, stirred and dissolved, followed by dissolving 0.26 g (0.1 mmol) of rhodium trichloride trihydrate in 20 ml of anhydrous ethanol. do. After about 30 seconds, 10 ml of formaldehyde is added and a solution of 0.322 g (14 mmol) of sodium metal is continuously added to 20 ml of anhydrous ethanol.

The mixture is heated to reflux with stirring for about an hour to obtain a yellow precipitate. The precipitate is washed and dried in the order of ethanol, water, ethanol, n-hexane to wash the unreacted product.

The obtained product was very high-hydrocarbonyl tris (triphenylphosphine) rhodium (I), the yield was 95%.

Example 2

Triphenylphosphine was added 20 times more than the rhodium compound, and potassium metal was dissolved in anhydrous ethanol solution instead of sodium metal, and the reaction was carried out in the same manner as in Example 1.

The yield of hydrocarbonyltris (triphenylphosphine) rhodium (I) was 95%.

Example 3

The experiment was conducted in the same manner as in Example 1 except that the sodium-potassium alloy instead of the sodium metal of Example 1 was dissolved in anhydrous ethanol. The yield of hydrocarbonyltris (triphenylphosphine) rhodium (I) was 95%.

Spectroscopic data and melting point of the rhodium catalyst RhHCO (PPh ₃ ) obtained in Examples 2 and ₃ are the same as those in Example 1.

Example 4

Tributylphosphine was used as the ligand to prepare a catalyst of formula (I) in the same manner as in Example 1. 1.0116 g (0.5 mmol) of tributylphosphine was dissolved in 20 ml of ethanol, and 0.13 g (0.05 mmol) of rhodium trichloride was added to 10 ml of ethanol, followed by heating with stirring. After about 30 seconds, a solution of 0.161 g (7 mmol) of sodium metal dissolved in 10 ml of formaldehyde and 10 ml of anhydrous ethanol was added and refluxed for 30 minutes to obtain a dark yellow solution. The solvent was evaporated and then crystallized with petroleum ether.

The yield of hydrocarbonyltris (tributylphosphine) rhodium (I) was 70%.

I.R data

Solution (n-hexane, cm ^-1 ) 2040 (Rh-H)

1940 (CO)

1150, 1220 (P-Bu)

Claims (1)

As described above in the text, after dissolving the rhodium compound in anhydrous alcoholic solution, an aldehyde having 1 to 4 carbon atoms and an alkali alcohol, such as sodium and potassium, and anhydrous alcoholic solution of sodium-potassium alloy as a reducing agent are rapidly added and stirred vigorously, A method for producing a rhodium catalyst having the structure of the following general formula (I) by refluxing the organophosphorus compound as a ligand. RhXCO (PR ₃ ) x... … (I) Wherein R is an alkyl or aryl group such as methyl, butyl, phenyl, X is hydrogen or halogen and X is an integer from 2 to 3.