JPH0813773B2 - Method for producing 2-chloropropionaldehyde - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to vinyl chloride, carbon monoxide and carbon monoxide according to the following reaction formula (1) CH ₂ = CHCl + CO + H ₂ → CH ₃ -CHCl-CHO (1). The present invention relates to a method for producing 2-chloropropionaldehyde using hydrogen as a raw material.

2-Chloropropionaldehyde can be used as a useful intermediate for chemicals and agricultural medicine.

(Problems to be Solved by Prior Art and Invention) Using vinyl chloride, carbon monoxide and hydrogen as raw materials 2-
Methods for producing chloropropionaldehyde are known, for example, French Patent No. 1,397,779 and HELVETICA CHIMICA ACTA, Volume 48, No. 5,
It is shown on pages 1151 to 1157. All of these methods use cobalt carbonyl as a catalyst, for example, according to the above-mentioned French Patent No. 1,397,779, a reaction temperature of 110 ° C.,
The reaction was carried out for 90 minutes under the reaction pressure of 200 atm, and the reaction results were 54.5% conversion of vinyl chloride and 86.2% selectivity of 2-chloropropionaldehyde. However, in the method of using these cobalt carbonyls as a catalyst, the catalytic activity per cobalt is extremely low. Therefore, a large amount of cobalt carbonyl and a high reaction pressure of 160 to 200 atm are required, and the reaction temperature of 75 to The method is such that the reaction is carried out at 125 ° C for 90 to 120 minutes. The target product, 2-chloropropionaldehyde, is a thermally unstable substance, and in order to reduce the reaction yield by consuming a considerable proportion in the sequential reaction under such reaction temperature and reaction time, This method has poor reproducibility,
Further, hydrogen chloride is by-produced by this sequential reaction or other side reaction, which corrodes the material of the reactor violently and reacts with the cobalt carbonyl catalyst to form cobalt chloride, which hinders the reuse of the catalyst. It has a problem that it brings it.

The inventors of the present invention have disclosed, as an improvement method for these, in JP-A-61-12.
6046, JP-A-62-10038, JP-A-62-22738 and JP-A-62-96444, vinyl chloride, carbon monoxide and hydrogen in the presence of a rhodium compound, a base and water. Have found a way to react to. According to this method, the reaction proceeds at a lower temperature and a lower pressure and sufficient selectivity to the desired product is obtained, as compared with the conventional method using a cobalt carbonyl catalyst. In this method, the base is represented by the general formula P (R ¹ R ² R ³ ) (wherein P represents a phosphorus atom, R ¹
R ² and R ³ each represent an alkyl group, an aryl group, a cycloalkyl group, an alkoxy group, an aryloxy group or a cycloalkoxy group), and a nitrogen-containing compound having a pKa of 3 to 11 Is preferably used. Among these nitrogen-containing compounds having a pKa of 3 to 11, pyridine compounds, quinoline compounds, imidazole compounds, triazole compounds, morpholine compounds and the like are particularly preferably used from the viewpoint of reaction results and the like.
However, as a result of detailed research, since all of these compounds are highly reactive compounds, some of them are deteriorated when used for a long time of one month or more, and the catalytic activity gradually decreases. all right. This catalytic activity can be maintained at a substantially constant value by supplementing these bases, but supplementing these compounds leads to an increase in production cost. The structural formulas of the compounds formed as a result of degeneration of these compounds in the reaction system are unknown, but the boiling points are considerably high, and it is difficult to separate them from the liquid in the reactor containing the catalyst component by normal operation. Therefore, it also has a problem that it hinders the reaction from continuing for a longer time.

An object of the present invention is to provide a method for producing 2-chloropropionaldehyde, which solves the above problems of the prior art.

(Means and Actions for Solving Problems) The present inventors have conducted detailed research for solving these problems. As a result, vinyl chloride, carbon monoxide and hydrogen are reacted in the presence of a rhodium compound and a base to give 2
-In the production of chloropropionaldehyde, a trivalent organic phosphorus compound or an oxide of a trivalent organic phosphorus compound is used as a base, and the reaction is efficiently performed in the presence of an acid having a pKa in the range of 0.5 to 5. The present invention has been completed by finding that the problems described above are solved in addition to the progress of the above.

That is, according to the present invention, vinyl chloride, carbon monoxide and hydrogen are reacted in the presence of a rhodium compound and a trivalent organophosphorus compound or an oxide of a trivalent organophosphorus compound to react with 2
-A method for producing 2-chloropropionaldehyde, characterized in that in producing chloropropionaldehyde, the reaction is carried out in the presence of at least one acid having a pKa in the range of 0.5 to 5.

Examples of the acid having a pKa of 0.5 to 5 used in the method of the present invention include various organic acids and inorganic acids. By using such an acid, the catalyst consisting of the rhodium and the base shows high activity, and when the production of 2-chloropropionaldehyde is continued for a long time, the acid is converted to these acids in the reaction system. No accumulation of high boiling substances derived from
It enables stable operation for a long time. At the same time, the number of times the catalyst liquid is regenerated can be reduced, so that the loss of expensive rhodium used as a catalyst can be reduced. In the method of the present invention, a carboxylic acid is preferably used as such an acid. Specific examples of the carboxylic acid include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, heptanoic acid, acrylic acid, methacrylic acid, crotonic acid, oxalic acid, malonic acid, methylmalonic acid, succinic acid, adipic acid. , Aliphatic saturated or unsaturated mono- or polycarboxylic acids such as maleic acid, fumaric acid and 1,2,3-propanetricarboxylic acid, and benzoic acid, toluic acid, o-
Ethylbenzoic acid, 2,4-dimethylbenzoic acid, phthalic acid,
Examples thereof include mono- or polyvalent aromatic carboxylic acids such as isophthalic acid, terephthalic acid, 3-methylphthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, benzenepentacarboxylic acid and meritic acid. In addition, halogens, amino groups, carboxylic acids having a substituent such as a hydroxyl group in the alkyl group or aryl group of these carboxylic acids are also preferable, and examples of these include monofluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, monochloroacetic acid, Dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, dibromoacetic acid,
2-chloropropionic acid, 3-chloropropionic acid, 2,
Halogen-substituted aliphatic carboxylic acids such as 2-dichloropropionic acid, o-chlorobenzoic acid, m-chlorobenzoic acid,
Halogen-substituted aromatic carboxylic acids such as p-chlorobenzoic acid and o-fluorobenzoic acid, glycine, sarcosine, alanine, β-alanine, 4-aminobutyric acid, valine, serine, aspartic acid, amino acids such as glutamic acid, glycolic acid, Lactic acid, 2-hydroxybutyric acid, glyceric acid,
Examples include hydroxycarboxylic acids such as malic acid, tartaric acid, citric acid, p-hydroxybenzoic acid, salicylic acid, and 2,4-dihydroxybenzoic acid. In addition, phenylacetic acid,
Preferable examples also include carboxylic acids having a substituent other than the above, such as pyruvic acid, anisic acid, o-nitrobenzoic acid, and cinnamic acid. Among these carboxylic acids, halogen-substituted aliphatic carboxylic acids and monovalent or polyvalent aromatic carboxylic acids are particularly preferably used in the method of the present invention.

Further, in the method of the present invention, phosphonic acids, phosphonous acids, phosphinic acids, or phosphinic acids are preferably used as the acid. Examples of these are
Methylphosphonic acid, ethylphosphonic acid, phenylphosphonic acid, phenylphosphonous acid, dimethylphosphinic acid,
Examples thereof include diethylphosphinic acid, diphenylphosphinic acid, diphenylphosphinous acid and the like.

In the method of the present invention, it is particularly preferable to carry out the reaction in the presence of water, as will be described later. At this time, it is also mentioned as a preferable example of the method of the present invention that the above-mentioned acid is supplied in the form of a precursor such as an ester, an acid chloride or an acid anhydride, which produces these acids in the presence of water. For example, ethyl acetate, methyl benzoate,
Esters such as dibutyl phthalate, diethyl phenylphosphonate, diethyl phenylphosphonite, acid chlorides such as acetyl chloride, benzoic acid chloride, diphenylphosphinic acid chloride, and acetic anhydride, maleic anhydride, phthalic anhydride, etc. The acid anhydride and the like are exemplified.

On the other hand, trivalent organic phosphorus compounds or oxides of trivalent organic phosphorus compounds preferably used in the method of the present invention are exemplified as follows.

That is, as the trivalent organic phosphorus compound, a compound represented by the general formula P (R ¹ R ²
R ³ ) (wherein P represents a phosphorus atom, and R ¹ , R ² and ³ each represent the same or different alkyl, aryl, cycloalkyl, alkoxy, aryloxy or cycloalkoxy group) Specific examples of the organic phosphorus compound include phosphines such as trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, triphenylphosphine, tricyclohexylphosphine, and tribenzylphosphine, and trimethylphosphite. Examples of phosphites such as triethyl phosphite, tripropyl phosphite, tributyl phosphite, trioctyl phosphite, triphenyl phosphite, tricyclohexyl phosphite, and tribenzyl phosphite. You.

In addition to the compounds represented by the above general formula P (R ¹ R ² R ³ ) as special phosphines, they are bonded to diphosphines such as bisdiphenylphosphinomethane and bisdiphenylphosphinoethane and crosslinked polystyrene. Phosphines and the like are also preferably used.

Further, as an oxide of a trivalent organic phosphorus compound, an alkylphosphine oxide such as triethylphosphine oxide, tributylphosphine oxide or trioctylphosphine oxide, an arylphosphine oxide such as triphenylphosphine oxide or tritolylphosphine oxide, or an alkyl group and an aryl Examples thereof include alkylarylphosphine oxide having a group. In addition to these, alkyl or aryl phosphite oxides such as triethyl phosphite oxide, tributyl phosphite oxide, and triphenyl phosphite oxide, and alkylaryl phosphite oxides having an alkyl group and an aryl group together can also be used. it can. Furthermore, oxides of polydentate phosphines such as bis-1,2-diphenylphosphinomethanedioxide can also be used.

Examples of the rhodium compound used in the method of the present invention include rhodium oxide, mineral acid salt, organic acid salt, and rhodium complex compound. Among these various rhodium compounds, a halogen-free rhodium compound is particularly preferable. Examples of these include rhodium oxide, rhodium nitrate, rhodium sulfate, rhodium acetate, triacetylacetonato rhodium, dicarbonyl acetylacetonato rhodium, dodecacarbonyl tetrarhodium, hexadecacarbonyl hexarhodium, and the like, and rhodium complex compounds. In addition to these, those in which a complex compound is formed with rhodium and a base are more preferably used.
The base may be a trivalent organic phosphorus compound or an oxide of a trivalent organic phosphorus compound which is preferably used in the method of the present invention, or may be another base.
Examples of these include hydridocarbonyltristriphenylphosphine rhodium [RhH (CO) (PP
h _{3) 3],} nitro silt list Li triphenylphosphine rhodium _{[Rh (NO) (PPh 3)} 3 ], .eta. cyclopentadienyl bis triphenylphosphine rhodium [Rh (C ₅ H ₅₎
(PPh ₃ ) ₂ ] and the like. Further, using a halogen-containing rhodium compound such as rhodium chloride, rhodium bromide, rhodium iodide or dichlorotetracarbonyl dirhodium,
It is also possible to add halogen compounds containing no halogen to the reaction system in an amount equal to or more than the amount of an alkaline compound such as sodium hydroxide, potassium hydroxide, potassium carbonate, trimethylamine or triethylamine. It can be used as a means.

In the method of the present invention, the rhodium compound has a rhodium atom content of 0.0001 to 1 per liter of liquid phase in the reaction system.
It is used in an amount corresponding to 1000 milligram atoms, preferably in the range of 0.001 to 100 milligram atoms. Further, the trivalent organic phosphorus compound used in the method of the present invention or the oxide of the trivalent organic phosphorus compound and the acid having a pKa in the range of 0.5 to 5 are:
Each is used in an amount of 0.1 to 500 mol, preferably 0.5 to 100 mol, per 1 gram atom of rhodium.

In the method of the present invention, the reaction proceeds without using a reaction solvent, but the reaction is usually performed in the presence of the reaction solvent. Any reaction solvent can be used as long as it does not adversely affect the reaction. Hydrocarbons are particularly preferable as such a solvent. More specifically, hexane, heptane, octane, nonane,
Saturated hydrocarbons such as decane and aromatic hydrocarbons such as benzene, toluene and xylene are preferably used, and ligroin, kerosene, gas oil, diesel oil and the like which are industrially obtained as a mixture of hydrocarbons are also used. Included in the example. In addition to these, ethers such as dipropyl ether and dibutyl ether, ketones such as diisobutyl ketone and holone, and esters such as butyl butyrate and butyl benzoate are also exemplified as preferable solvents.

In the method of the present invention, a method in which water coexists in the reaction system is more preferably carried out. By taking such a method, the catalytic activity is further improved. In the method of the present invention, the amount of water to be present during the reaction is not particularly limited, but when the amount is extremely small, the effect is small, and even when the amount is extremely large, the reaction result does not increase to some extent. Usually, the amount of water is preferably 0.01 or more and 1000 or less in weight ratio with respect to vinyl chloride supplied to the reactor as a raw material. Particularly, the range of 0.1 to 100 is more preferably used. When the acid having a pKa of 0.5 to 5 used in the method of the present invention is water-soluble, a method of introducing these acids into the reaction system in the form of an aqueous solution or removing them from the reaction system is used. It is preferably used to simplify the operation.

The method of the present invention is usually carried out at a reaction temperature of 10 to 150 ° C. and a reaction pressure of 10 to 300 Kg / cm ² gage, preferably 30 to 150 Kg / c.
It is done in the m ² gauge range. The reaction temperature is preferably as low as possible from the viewpoint of the thermal stability of the produced 2-chloropropionaldehyde, and for this reason, 20-80 ° C is a particularly preferred temperature range. The mixing molar ratio of carbon monoxide and hydrogen of the raw materials is usually in the range of 10 to 0.1, preferably 4 to 0.2.
Range. Carbon monoxide and hydrogen may be mixed gas containing both components in the above composition ratio, water gas,
A water gas containing methane, a gas inert to the reaction such as nitrogen, or carbon dioxide is used. The other raw material, vinyl chloride, is used in the form of gas, liquid, or solution dissolved in the solvent used for the reaction. The method of the present invention can be carried out by any of a batch method, a semi-batch method and a continuous method. For example, in the case of the batch method, the rhodium compound, the trivalent organic phosphorus compound or the oxide and pKa of the trivalent organic phosphorus compound are 0.5 to 5
To the autoclave charged with the acid in the range of 1 and the reaction solvent and water as required, add vinyl chloride in the form of gas, liquid or solution, and introduce the gas containing carbon monoxide and hydrogen up to the specified pressure. However, the reaction proceeds preferably by heating with stirring. Examples of the continuous method include rhodium compounds, trivalent organic phosphorus compounds or oxides and pKa of trivalent organic phosphorus compounds.
An acid in the range of 0.5 to 5 and optionally a reaction solvent and water, and raw materials vinyl chloride, carbon monoxide and hydrogen are continuously supplied to one of the pressure resistant reactors and stirred at a reaction temperature. The reaction is carried out under the conditions by continuously withdrawing the reaction mixture from the other and unreacted vinyl chloride, carbon monoxide and hydrogen.

(Examples) Hereinafter, the method of the present invention will be described more specifically with reference to Examples.

Example 1 After replacing the inside of a stainless steel autoclave with an internal volume of 100 ml equipped with a stirrer with nitrogen gas, 36 mg of hexadecacarbonylhexarodium (Rh 0.2 mg atom)
Then, 208 mg (0.8 mmol) of triphenylphosphine, 194 mg (1.5 mmol) of dichloroacetic acid and 20 g of water were added, and 20 ml of a toluene solution of vinyl chloride containing 1.88 g (30 mmol) of vinyl chloride was added thereto. In this autoclave,
A mixed gas of carbon monoxide and hydrogen in a molar ratio of 1: 2 was injected at room temperature until the pressure reached 80 kg / cm ² gauge, then the temperature was raised to 55 ° C., and the reaction was carried out for 40 minutes. After cooling the autoclave to room temperature, the unreacted raw material mixed gas was collected in a gas sampling bag, the autoclave was opened, and the reaction mixed solution containing the catalyst, the solvent and the reaction product was taken out. As a result of quantifying the gas and the liquid by gas chromatography, the conversion rate of vinyl chloride was 32.4%, and the production amount of 2-chloropropionaldehyde was 8.8 mmol (selectivity based on the converted vinyl chloride was 90.5%).

Examples 2 to 5 The reaction was carried out by changing the reaction temperature, the reaction pressure, the molar ratio of carbon monoxide and hydrogen, and the reaction time in the method of Example 1. The results are shown in Table 1.

Examples 6 to 9 In the method of Example 1, the types of rhodium compound, base and acid were changed to carry out the reaction. The amount of the rhodium compound was set so that rhodium would be 0.2 mg atom. Table 2 shows the results.

Examples 10 to 13 In the method of Example 1, the reaction was carried out using various acids or acid precursors instead of dichloroacetic acid. The results are shown in Table 3.

Example 14 The reaction was performed in the same manner as in Example 1 except that water was not used.

As a result of the analysis, a reaction result was obtained in which the conversion of vinyl chloride was 9.8% and the selectivity of 2-chloropropionaldehyde was 89.1%.

Example 15 Pressure resistance with 7-stage impeller and hot water jacket
200Kg / cm ² gauge reactor (made of SUS 316, inner diameter 30mm, height
450mm, actual volume about 300cm ³ ), temperature 50 ℃, pressure 80Kg / cm ²
A rhodium catalyst solution (20 mmol of hydridocarbonyltristriphenylphosphine rhodium, 40 mmol of triphenylphosphine, 40 mmol of 2-phenylpropionaldehyde, 4.
Toluene solution containing 8 g and 15 mmol of dichloroacetic acid) 800 cm ³ / hour, dichloroacetic acid aqueous solution (containing 1 mol of dichloroacetic acid per 1) 900 ml / hour, vinyl chloride 2.2 mol / hour
Hourly, and a mixed gas of carbon monoxide and hydrogen at a molar ratio of 1: 2, 320 / hour, is continuously supplied, and at the same time, a reaction mixture including an aqueous layer and an organic layer is obtained from a take-out pipe provided at the upper part of the reactor. The liquid and unreacted vinyl chloride, carbon monoxide and hydrogen were continuously withdrawn to a gas-liquid separator operating at 35 ° C. and at the same pressure as the reactor. In the gas-liquid separator, most of unreacted vinyl chloride and unreacted carbon monoxide and hydrogen are taken out from a gas outlet provided in the upper part of the gas-liquid separator, and are brought to atmospheric pressure through a pressure control valve. It was sent to the retained unreacted gas holder. On the other hand, the reaction liquid mixture was taken out from a liquid outlet provided in the lower part of the gas-liquid separator and sent to a stationary separation tank operated at atmospheric pressure via a liquid level control valve. Here, the reaction mixture is the upper organic layer (toluene layer)
And the lower water layer. 22g in this organic layer
Contains 2-chloropropionaldehyde,
By washing this with water, the content of 2-chloropropionaldehyde was lowered to 4.8 g. This liquid had substantially the same composition as the rhodium catalyst liquid described above, and was mixed with the rhodium catalyst liquid supplied to the reactor and reused.
On the other hand, the aqueous layer was subjected to batch distillation to separate 2-chloropropionaldehyde, and dichloroacetic acid was recovered and reused. In this way, continuous operation was carried out for 96 hours. The amount of 2-chloropropionaldehyde produced per hour is about ± 6 hours after the start of operation.
It became almost constant within the range of about 5%, and remained almost constant until 96 hours thereafter. 84 hours from the 80th hour after the reaction started
By the average of 4 hours until the hour, about 85g per hour 2
It was found from gas chromatographic analysis of the aqueous layer that chloropropionaldehyde had been produced.

Immediately after the start of this continuous reaction and 96 hours later, a part of the toluene layer was taken out, and it was examined by gas chromatography whether or not high boiling point components were accumulated. SE-for gas chromatograph
A 1 m glass column packed with 30 was used. Column temperature is
The temperature was set to 180 ° C. (constant temperature), nitrogen was used as a carrier gas, and a FID detector was used as a detector. As a result of the analysis, accumulation of high boiling point components was not observed in the toluene layer within the detection range of the gas chromatograph.

Comparative Example 1 In the method of Example 15, an experiment was conducted using the same number of moles of imidazole instead of dichloroacetic acid. Since a slight decrease in activity was observed from about 72 hours after the start of the reaction, about 15 g of imidazole was replenished per water, and the activity was recovered to almost the same level. However, in the analysis of the toluene layer after 96 hours by the gas chromatography, a high boiling point component which was not observed in Example 11 was detected. The boiling point of this component was estimated to be approximately 350 ° C from analysis by gas chromatography. Furthermore, when this component was examined by a gas chromatograph-mass spectrometer, it was found that it was a compound containing nitrogen although its structure was unknown and its molecular weight was 349. Since this compound cannot be distilled from the toluene layer by distillation, in order to return the catalyst to the same composition as the new catalyst, for example, the toluene layer is burned and then treated with aqua regia to recover rhodium, This was once converted to rhodium chloride, converted to rhodium carbonyl, and then a means such as addition of another catalyst component such as phosphine was required.

(Effects of the Invention) By the method of the present invention, vinyl chloride, carbon monoxide and hydrogen are used as raw materials at a low temperature and a low pressure to achieve high selectivity.
-Chloropropionaldehyde can be produced. In particular, according to the method of the present invention, it becomes possible to stably maintain a high activity for a long time without accumulating by-products in the reaction system. Further, according to the method of the present invention, since it is less necessary to frequently regenerate the catalyst, it is possible to reduce the loss of rhodium that accompanies this.

Claims (6)

[Claims] 1. To produce 2-chloropropionaldehyde by reacting vinyl chloride, carbon monoxide and hydrogen in the presence of a rhodium compound and a trivalent organic phosphorus compound or an oxide of a trivalent organic phosphorus compound, PKa the reaction
The method for producing 2-chloropropionaldehyde is carried out in the coexistence of at least one acid having a ratio of 0.5 to 5. 2. The first claim in which the acid is a carboxylic acid.
The method described in the section. 3. The method according to claim 1, wherein the acid is phosphonic acid, phosphonous acid, phosphinic acid, or phosphinic acid. 4. The method according to claim 2, wherein the acid is a halogen-substituted aliphatic carboxylic acid. 5. The method according to claim 2, wherein the acid is a monovalent or polyvalent aromatic carboxylic acid. 6. The method according to any one of claims 1 to 5, wherein the reaction is carried out in the presence of water.