JPH03190836A - Production of 2-chloropropionaldehyde - Google Patents

Abstract

PURPOSE:To obtain the subject compounded at a low temperature under a low pressure in high selectivity by reacting vinyl chloride with CO and H2 in the presence of the solution of a catalyst which is prepared by reacting a Rh compound and a trivalent organic phosphorus compound or an oxide thereof with CO or a mixture of CO and H2 in an organic solvent. CONSTITUTION:When vinyl chloride, carbon monoxide and hydrogen gas as raw materials are subjected to two reaction steps to obtain 2-chloro propionaldehyde, a rhodium compound, a trivalent organic phosphorus compound or an oxide thereof and carbon monoxide or a mixture of the carbon monoxide with hydrogen gas are reacted with each other in a water-insoluble or slightly soluble organic solvent to prepare a catalyst solution (the first reaction step). Vinyl chloride, carbon monoxide and hydrogen gas are reacted with each other in the presence of the prepared catalyst solution to obtain 2- chloropropionaldehyde (the second reaction step). The second step reaction is preferably performed in the presence of an organic acid and/or a base, water or a mixture of the organic acid, the base and the water.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing 2-chloropropionaldehyde using vinyl chloride, carbon monoxide and hydrogen as raw materials according to the following reaction formula %.

2-chloropropionaldehyde can be used as a useful intermediate for various chemicals and agricultural chemicals.

(Prior Art) A method for producing 2-chloropropionaldehyde using vinyl chloride, carbon monoxide and hydrogen as raw materials is known, for example, as described in French Patent No. L397,779 and IIELVETICA Cllll1'. 1lC
AACTA), Vol. 48, No. 5, pp. 1151-115
It is shown on page 7. All of these methods use cobalt carbonyl as a catalyst, and for example, according to the French Patent Box No. 1,397.779, the reaction temperature is 110°.
The reaction was carried out for 90 minutes under the condition of a C1 reaction pressure of 200 atm, and the reaction results were obtained with a vinyl chloride addition rate of 57.4% and a 2-chloropropionaldehyde selectivity of 86.2%. However, in these methods using cobalt carbonyl as a catalyst, the catalytic activity per cobalt is extremely low, and therefore a large amount of cobalt carbonyl and 16
In addition to requiring a high reaction pressure of 0 to 200 atm,
A method is used in which the reaction is carried out for 90 to 120 minutes at a reaction temperature of 75 to 125°C. The target product, 2-chloropropionaldehyde, is a thermally unstable substance, and at such reaction temperatures and times, a considerable proportion of it is consumed in the sequential reactions, reducing the reaction yield. However, this method has poor reproducibility, and this sequential reaction or other side reactions produce hydrogen chloride, which severely corrodes the reactor material and reacts with the cobalt carbonyl catalyst to form cobalt chloride. This also poses a problem in that it poses a problem in reusing the catalyst.

The present inventors have developed a method for improving these methods using Japanese Patent Application Laid-Open No. 61-1
No. 26046, JP-A-62-10038, JP-A-62
-22738, Jikai No. 62-270540 and JP-A No. 62-270541, vinyl chloride, carbon monoxide and hydrogen are combined with rhodium compounds, trivalent organophosphorus compounds or trivalent organophosphorus compound oxides. and a method of reacting in the presence of water.

According to this method, compared to the conventional method using a cobalt carbonyl catalyst, the reaction proceeds at a lower temperature and lower pressure, and high selectivity to the target product can be obtained. However, as a result of detailed research, it has become clear that there are unfavorable problems in the process depending on the properties of the rhodium compound used. That is, when a rhodium compound that is insoluble or poorly soluble in the reaction solvent is used, an induction period exists, and rhodium species that are insoluble in the reaction solvent often remain after the reaction. When using a water-soluble rhodium compound, there is an induction period and some rhodium species remain in the water layer.
Its recovery increases manufacturing costs. Furthermore, when using rhodium compounds that are soluble in the reaction solvent and insoluble in water, an induction period was often observed. The induction period and the appearance of insoluble materials that cause pipe clogging are a hindrance to the process. Due to the above-mentioned problems, inexpensive rhodium compounds could not be used.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing 2-chloro-1-lobionaldehyde that solves the above-mentioned problems of the conventional technology.

(Means for Solving the Problems) The present inventors conducted detailed research to solve these problems. As a result, (a) a rhodium compound, (b) a trivalent organic phosphorus compound or a trivalent organic phosphorus compound oxide, and (c) carbon monoxide or carbon monoxide and hydrogen are reacted in the presence of an organic solvent. In the presence of the obtained catalyst liquid,
In order to complete the present invention, we discovered a process for producing 2-chloropropionaldehyde in which there is no induction period when vinyl chloride, carbon monoxide, and hydrogen are reacted, and in which no insoluble matter is observed in the reaction system. It's arrived.

That is, the present invention provides (a) a rhodium compound, (b) a trivalent organic phosphorus compound or an oxide of a trivalent organic phosphorus compound, and (c) carbon monoxide or carbon monoxide and hydrogen in a water-insoluble or poorly water-soluble form. A first reaction step of reacting in the presence of a soluble organic solvent to obtain a catalyst solution, and reacting vinyl chloride, carbon monoxide, and hydrogen in the presence of the catalyst solution to obtain a catalyst containing 2-chloropropionaldehyde. This is a method for producing 2-chloropropionaldehyde, characterized by comprising a second reaction step of obtaining a reaction mixture.

The trivalent organic phosphorus compound or the oxide of the trivalent organic phosphorus compound preferably used in the method of the present invention is exemplified as follows.

That is, as a trivalent organic phosphorus compound, the general formula, P (R
'R2R3) (here, P represents a phosphorus atom, R', R''
, R3 is the same or different alkyl group, aryl group, cycloalkyl group, alkoxy group, aryloxy group or cycloalkoxy group), and specifically, Phosphines such as trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, trioctylbosphine, triphenylphosphine, tricyclohexylphosphine, tribenzylphosphine, trimethylbosphite, triethylphosphine,
Tripropyl phosphite, tributyl phosphite,
Examples include phosphites such as trioctyl phosphite, triphenylbosphite, tricyclohexyl phosphite, and trihensyl bosphite.

As a special type of bosphin, the above-mentioned general 2P (
In addition to those represented by R'R''R3), diphosphines such as bisdiphenylphosphinomethane and bisdiphenylphosphinoethane, and bosphines bonded to crosslinked polystyrene are also preferably used.

Oxides of trivalent organic phosphorus compounds include alkylphosphine oxides such as triethylphosphine oxide, tributylphosphine oxide and triethylphosphine oxide, arylphosphine oxides such as triethylphosphine oxide and tritolylphosphine oxide, or alkyl and aryl groups. Examples include alkylarylphosphine oxide having a combination. In addition, trimethylbosphite oxide,
Alkyl or aryl phosphite oxides such as triethylbosphite oxide, tripropyl phosphite oxide, tributyl phosphite oxide, trioctyl phosphite oxide, triphenyl phosphite oxide, tricyclohexyl bosphite oxide, tribenzyl phosphite oxide, Alkylarylbosphite oxides having a combination of an alkyl group and an aryl group can be used. Furthermore, polydentate phosphine oxides such as bis-1,2 diphenylphosphinomethane dioxide can also be used.

Examples of the rhodium compound used in the method of the present invention include rhodium acid compounds, mineral acid salts, organic acid salts, and rhodium complex compounds. Examples of these are rhodium chloride, rhodium bromide, rhodium iodide, rhodium oxide,
Rhodium nitrate, rhodium sulfate, rhodium acetate, triacetylacetonatrhodium, dichlorotetracarbonyl dirhodium, dicarbonylacetylacetonate rhodium, dodecacarbonylhexalodium, hexadecacarbonylhexalodium, and the like. In addition to these rhodium complex compounds, complex compounds formed by rhodium and a base are also preferably used. The base may be a trivalent organic phosphorus compound or an oxide of a trivalent organic phosphorus compound. Examples of these include, for example, nitrosyltris-1-rephenylphosphine rhodium [17I+ (No) (PPhs) s ], ]η
-Cyclopencgenyl bistriphenylphosphine rhodium Rh (csHs) (PPh+) 21 and the like.

The organic acids used in the method of the present invention include various carboxylic acids. Examples of carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, -
・Butanoic acid, acrylic acid, meccrylic acid, crotonic acid,
Aliphatic saturated or unsaturated mono- or polycarboxylic acids such as oxalic acid, malonic acid, methylmalonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, 1,2.3-propanetricarboxylic acid, and benzoic acid, toluyl acid, 0-ethylbenzoic acid, 2,4-dimethylbenzoic acid, phthalic acid,
Isophthalic acid, terephthalic acid, 3-methylphthalic acid, l
- Monovalent or polyhydric aromatic carboxylic acids such as limellitic acid, trimesic acid, pyromellitic acid, benzenepentacarboxylic acid, and limellitic acid. Also preferred are carboxylic acids in which a substituent such as a halogen, an amino group, or a hydroxyl group is attached to the alkyl group or aryl group of these carboxylic acids. Examples of these are monofluoroacetic acid, difluoroacetic acid,
Trifluoroacetic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid 1, dibromoacetic acid, 2-
Chloropropionic acid, 3-chloropropionic acid, 2,2
-Halogen-substituted aliphatic carboxylic acids such as dichloropropionic acid, 0-chlorobenzoic acid, m-[JI]benzoic acid, p-chlorobenzoic acid, 0-fluorobenzoic acid, etc.
Cogen-substituted aromatic carboxylic acid, glycine, sarcosine,
Amino acids such as alanine, β-alanine, 4-aminobutyric acid, valine, serine, aspartic acid, glutamic acid, glycolic acid, lactic acid, 2-hydroxybutyric acid, glyceric acid, malic acid, tartaric acid, citric acid, p-hydroxybenzoic acid, Examples include salicylic acid and 2,4-dihydroxybenzoic acid. In addition, phenylacetic acid, pyruvic acid, anisic acid,
Preferred examples include acids with substituents other than those mentioned above, such as 0-nitrobenzoic acid and cinnamic acid. In the method of the present invention, among these carboxylic acids, halogen-substituted aliphatic carboxylic acids and -valent or polyvalent aromatic carboxylic acids are particularly preferably used.

In the method of the present invention, the second reaction step is particularly preferably carried out in the presence of water, as described below.

At this time, a preferred example of the method of the present invention is to supply the above-mentioned acid in the form of a precursor such as an ester, an acid chloride, or an acid anhydride, which generates these acids in the presence of water. For example, esters such as ethyl acetate, methyl benzoate, dibutyl phthalate, acetyl chloride,
Examples include carboxylic acid chlorides such as benzoic acid chloride, and acid anhydrides such as acetic anhydride, maleic anhydride, and phthalic anhydride.

In the method of the present invention, sodium hydroxide, potassium hydroxide, lithium hydroxide, cesium hydroxide,
Alkali metal or alkaline earth metal hydroxides such as calcium hydroxide, helium hydroxide, magnesium hydroxide, strontium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, calcium carbonate,
Alkali metal or alkaline earth carbonates such as beryllium carbonate, magnesium carbonate, strontium carbonate, alkali metal or alkaline earth metal carbonates such as sodium bicarbonate, potassium bicarbonate, lithium bicarbonate, cesium bicarbonate, calcium bicarbonate, etc. Examples include weak acid salts of alkali metals or alkaline earths such as carbonates, sodium acetate, potassium formate, and magnesium acetate. Among these bases, compounds of sodium, potassium, cesium and calcium are particularly preferably used in the method of the present invention.

In the method of the present invention, the base has a pKa of 3 to 1.
A nitrogen-containing compound within the range of 1 is used.

Examples include, in general, compounds containing amino groups,
For example, aliphatic amines, aromatic amines, diamines, triamines, amino alcohols, amino acids, amides, urea compounds, guanidines, amidines, or an alkyl group on the nitrogen or carbon atom of these compounds. , among nitrogen-containing compounds containing substituents such as carboxyl groups, hydroxyl groups, or halogens, those with pKa of 3 to
Eleven compounds within the range are mentioned. Examples of such compounds include primary amines such as methylamine, ethylamine, propylamine, pudylamine, aniline, cycloalkyl groups, dimethylamine, diethylamine,
Examples include secondary amines such as dipropylamine, dibdelamine, diphenylamine, and dicyclohexylamine, and tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, triphenylamine, and tricyclohexylamine.

In addition, among heterocyclic compounds containing one or more nitrogen atoms as a base, compounds having a pea in the range of 3 to 11 may also be used. Among these, at least one of a pyridine compound, a quinoline compound, an imidazole compound, or a morpholine compound having a pKa of 3 to 11 is more desirable. Specific examples of these bases are as follows.

As a pyridine compound, the following general formula (wherein, RI,
R2, R3, R4 and R5 are each hydrogen,
Among the compounds represented by alkyl group, aryl group, cycloalkyl group, halogen, hydroxyl group, alkoxy group, carboxy group, or acetyl group, pKa is 3 to 3.
There are 34 pyridine compounds within the range of 11, examples of which include pyridine, picoline, ethylpyridine, 2,4-lutidine, α-
Examples include collidine, phenylpyridine, cyclohexylpyridine, benzylpyridine, 3-pyridinol, methoxypyridine, phenoxypyridine, and aminopyridine.

Other examples of pyridine compounds include polynuclear pyridines such as 2,2''-bispyridine.

Examples of quinoline compounds include 2-methylquinoline, dimethylquinoline, phenylquinoline, methoxyquinoline, etc. in addition to quinoline, and various isoquinoline compounds can also be used.

The imidazole compound has the general formula (wherein R+, Rt, R3 and R4 each represent hydrogen, an alkyl group or a cycloalkyl group, and R3 and R4 include carbon at the 4.5-position of the imidazole ring. Among the compounds represented by (may form a condensed imidazole that forms a ring), there are compounds whose pea is within the range of 3 to 11, and examples of these include imidazole, N-methylimidazole, N-methylimidazole, Ethylimidazole, 2
-Methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, N-hensyl-2-methylimidazole,
2.4.5-) Rifunilimidazole, 2-phenylbenzimidazole, and the like.

Examples of morpholine compounds include morpholine, N
-Methylmorpholine, N-ethylmorpholine, and the like.

In the method of the present invention, the reaction proceeds without using a reaction solvent, but the reaction is usually carried out in the presence of a reaction solvent. Any reaction solvent can be used as long as it does not adversely affect the reaction. Hydrocarbons are particularly preferred as such solvents. More specifically, saturated hydrocarbons such as hexane, heptane, octane, nonane, and decane, aromatic hydrocarbons such as benzene, toluene, and xylene are preferably used, and mixtures of hydrocarbons are preferably used. Industrially obtained ligroin, kerosene,
Light oil, diesel oil, etc. are also included in these examples. In addition, ethers such as dipropyl ether and dibutyl ether, ketones such as diisobutyl ketone and boron,
Examples of preferred reaction solvents include esters such as butyl butyrate and butyl benzoate.

In the method of the present invention, the rhodium compound used in both the first reaction step and the second reaction step is 0.0001 to 1 gram atom, preferably 0.001 gram atom, as rhodium atom per liter of liquid phase in the reaction system. The amount used is equivalent to within the range of ~0.1 gram atom.

The trivalent organophosphorus compound or the oxide of the trivalent organophosphorus compound, the organic acid, and the base used in the method of the present invention are each 0.1 to 500 mol per gram atom of rhodium;
It is preferably used in a range of 0.5 to 100 mol.

In the method of the present invention, the first reaction step for obtaining a catalyst liquid is carried out at a reaction temperature of 10 to 200'C2 and a reaction pressure of normal pressure or elevated pressure. However, although carrying out the process under pressure has the advantage that the processing time is shorter, it can also be carried out satisfactorily under atmospheric pressure. Regarding carbon monoxide, pure carbon monoxide is used, but mixed gases containing carbon oxide can also be used, such as water gas, water gas and gases inert to the reaction such as methane and nitrogen, carbon dioxide, Those containing olefin, acetylene, etc. are also used.

The mixing molar ratio when using carbon monoxide and hydrogen is usually in the range of 10 to 0.1, preferably in the range of 5 to 0.2. Carbon monoxide and hydrogen may be mixed gases containing both components in the above-mentioned composition ratio, such as water gas, water gas, methane, nitrogen, or other inert gas, carbon dioxide, olefin, acetylene, etc. It can also be used even if it contains

The second reaction step of the present invention is more preferably carried out by a method in which water is allowed to coexist. By adopting such a method, the catalytic activity is further improved. In the method 8 of the present invention, there is no particular restriction on the amount of water present during the reaction, but if the amount is extremely small, the effect will be reduced. Even when an extremely large amount of water is used, the reaction performance does not improve beyond a certain level.

Usually, the amount of water is preferably within the range of 0.01 or more and 1000 or less in terms of weight ratio to the vinyl chloride supplied to the reactor as a raw material. A range of 0.1 to 100 is particularly preferably used. In the method of the present invention, the activity is improved by using an organic acid, a base, or an organic acid and a base, but when the organic acid or base used is water-soluble, these organic acids and bases may be used in water-soluble form. A method in which the compound is introduced into the reaction system or taken out from the reaction system is preferably used in order to simplify the reaction operation.

In the second reaction step of the present invention, the reaction temperature is usually 10
The reaction is carried out in the range of ~150'C1 reaction pressure 10-300 kg/cm2 gauge pressure. The reaction temperature is 2-
In view of the thermal stability of chloropropionaldehyde, low temperatures are preferred, and a particularly preferred temperature range is 20 to 80°C. The mixing molar ratio of carbon monoxide and hydrogen as raw materials is usually in the range of 10 to 0.1, preferably in the range of 5 to 0.2. Carbon monoxide and hydrogen may be mixed gases containing both components in the above-mentioned composition ratio, and may be water gases, water gases containing gases inert to the reaction such as methane or nitrogen, or carbon dioxide, etc. things are used. The other raw material, vinyl chloride, is used in the form of a gas, liquid, or solution dissolved in the solvent used in the reaction.

The method of the present invention can be carried out by a batch method, a semi-batch method, or a continuous method. For example, in the case of a batch method, carbon monoxide or The reaction is carried out by introducing a gas containing carbon monoxide and hydrogen up to a predetermined pressure and heating, preferably with stirring. It is also possible to carry out the reaction in the first reaction step without applying pressure by flowing carbon monoxide or a gas containing carbon monoxide and hydrogen under atmospheric pressure and heating it. After the completion of the reaction in the first reaction step, an organic acid aqueous solution, gas, liquid, or vinyl chloride in the form of a solvent is added to the autoclave, and a gas containing carbon monoxide and hydrogen is introduced to the autoclave to a predetermined pressure. The reaction in the second reaction step is preferably carried out by heating with stirring. For example, in the case of a continuous process, a rhodium compound, a trivalent organophosphorus compound or an oxide of a trivalent organophosphorus compound, and optionally a reaction solvent are added to a catalyst preparer, and carbon monoxide or carbon monoxide is added to the catalyst preparer. Hydrogen-containing gas is filled to a predetermined pressure, and the catalyst liquid obtained after reaction is continuously extracted and supplied to the next pressure-resistant reactor.

An organic acid and/or base, and if necessary a reaction solvent and water, as well as the raw materials vinyl chloride and hydrogen, are continuously fed from one inlet of the reactor, and under stirring conditions, the other outlet is fed. The reaction is carried out by continuously extracting the reaction mixture, unreacted vinyl chloride, carbon monoxide and hydrogen from the reactor.

(Example) The method of the present invention will be explained in more detail with reference to Examples.

Example 1 First reaction process After replacing the inside of a stainless steel autoclave with an internal volume of 100 m1 equipped with a stirring device with nitrogen gas, 36 mg (Rh 0.2
milligram atom) and triphenylbosphine 156
mg (0.6 mmol) and 10 ml of toluene were added. A mixed gas of carbon monoxide and hydrogen with a molar ratio of 1:2 was added to this autoclave at a pressure of 40 kg/cm at room temperature.
After pressurizing to 2 gauge pressure, the temperature was raised to 70°C and reacted for 60 minutes. The autoclave was cooled to room temperature and then depressurized. The resulting catalyst liquid was completely homogeneous.

Second reaction step: Into an autoclave containing the catalyst solution treated above, 830 mg (5.0 mmol) of fucuric acid, 150 mg (3.75 mmol) of sodium hydroxide, 20 g of water, and 60 mmol of vinyl chloride were added. Toluene on vinyl? Yon Pj, powered 20m1. This auto track I/-
A mixed gas of carbon monoxide and hydrogen in a molar ratio of 1:2 was injected into the reactor at room temperature until the pressure reached 80 kg/cm2 gauge pressure, and then the temperature was raised to 50°C and reacted for 20 minutes. After the autoclave was cooled to room temperature and unreacted raw material mixed gas was collected in a gas sampling bag, the autoclave was opened and the reaction mixture containing the catalyst, solvent, and reaction product was taken out. As a result of quantifying the gas and liquid by gas chromatography, the conversion rate of vinyl chloride was 29.2%.
The amount of 2-chloropropionaldehyde produced is 16.55
mmol (selectivity based on converted vinyl chloride is 94.5
%)Met.

Comparative Example 1 After replacing the inside of a stainless steel autoclave with an internal volume of 100 m1 equipped with a stirring device with nitrogen gas, hexadecacarbonyl hexalodium, 36 mg (Rh 0.2
milligram atom) and triphenylphosphine 156
mg (0.6 mmol), phthalic acid 830 mg (5
,0 mmol), sodium hydroxide 150 mg (3,7
5 mmol), 20 g of water, and 30 ml of a toluene solution of vinyl chloride containing 60 mmol of vinyl chloride were added. A mixed gas of carbon monoxide and hydrogen with a molar ratio of 1:2 was injected into the autoclave at room temperature until the pressure reached 80 kg/cm'' gauge pressure, then the temperature was raised to 50°C, and the temperature was raised to 50°C.
Allowed to react for minutes. After the autoclave was cooled to room temperature and unreacted raw material mixed gas was collected in a gas sampling bag, the autoclave was opened and the reaction mixture containing the catalyst, solvent, and reaction product was taken out. Insoluble rhodium compounds were confirmed.

As a result of quantifying gas and liquid by gas chromatography,
The conversion rate of vinyl chloride was 15.5%, and the amount of 2-chloropropionaldehyde produced was 8.74 mmol (selectivity based on converted vinyl chloride was 94.0%).

Examples 2 to 8 In the method of Example 1, the reaction was carried out by changing the rhodium species and the reaction conditions of each step. The catalyst liquid obtained in the first reaction step was uniform after cooling. The results after all steps are shown in Table 1.

Example 9 4 First reaction step After replacing the inside of a stainless steel autoclave with an internal volume of 100 m1 equipped with a stirring device with nitrogen gas, 36 mg of hexadecacarbonyl hexalodium (Rh 0.2
milligram atom) and triphenylbosphine 156
mg (0.6 mmol), dichloroacetic acid 645 m
g (5.0 mmol) and 10 ml of toluene were added. A mixed gas of carbon monoxide and hydrogen with a molar ratio of 1:2 was placed in this autoclave at a pressure of 40 kg/cm at room temperature.
After press-fitting until gauge pressure is reached, the temperature is raised to 70°C,
The reaction was allowed to proceed for 60 minutes. The autoclave was cooled to room temperature and then depressurized. The resulting catalyst liquid was completely homogeneous.

Second Reaction Step The same process as in Example 1 was carried out except that 830 mg of phthalic acid was not added, and the conversion rate of vinyl chloride was 27.
4%, the amount of 2-chloropropionaldehyde produced is 15
．． 6 mmol (selectivity based on converted vinyl chloride is 94
．． 7%).

Examples 10 to 13 In the method of Example 2, the reaction was carried out by changing the rhodium species and the reaction conditions of each step. The catalyst liquid obtained in the first reaction step was uniform after cooling. The results after all steps are shown in Table 1.

Example 14 First reaction step Pressure resistance 100 kg/c equipped with stirrer and hot water jacket
1 gauge pressure catalyst preparation device (made of SO3316, content approx. 1
02) were charged with 80 mmol of rhodium chloride hydrate, 640 mmol of triphenylphosphine, and 5 liters of toluene.
The container was filled to a pressure of 1.5 cm" gauge. After the temperature was raised to 70°C, stirring was performed for 30 minutes.

Second reaction process Pressure 20 with 7-stage impeller stirrer and hot water jacket
0 kg/cm” gauge pressure reactor (manufactured by SLI3316,
The internal volume is approximately 300 cm'3), the temperature is 40°C, the pressure is 5
Maintaining the pressure at 0 Kg/cm2 gauge pressure, 200 cm3/hour of the obtained catalyst solution was added to the inlet pipe provided at the bottom of the reactor, and an aqueous solution of dichloroacetic acid hydroxide (0.25 mol of dichloroacetic acid and sodium hydroxide per liter). 0.
1000 ml/h (containing 1.88 mol), 2.2 mol/h of vinyl chloride, and 320 liters/h of a mixed gas of carbon monoxide and hydrogen in a molar ratio of 1:2, and at the same time, From the take-out pipe installed at the top of the reactor,
The reaction mixture containing an aqueous layer and an organic layer, unreacted vinyl chloride, carbon monoxide, and hydrogen are continuously taken out to a gas-liquid separator operated at 35°C and at the same pressure as the reactor. Ta. In the gas-liquid separator, most of the unreacted vinyl chloride and unreacted carbon monoxide and hydrogen are taken out from the gas outlet provided at the top of the gas-liquid separator, and brought to atmospheric pressure through a pressure regulating valve. Contained unreacted gas was sent to the holder.

On the other hand, the reaction mixture was taken out from a liquid outlet provided at the bottom of the gas-liquid separator, and sent to a static separation tank operated at atmospheric pressure via a liquid level adjustment valve.

Here, the reaction mixture was separated into an upper organic layer (toluene layer) and a lower aqueous layer. 5% (by weight) of 2-chloropropionaldehyde is present in the organic layer, and 4.0% (by weight) of 2-chloropropionaldehyde is present in the aqueous layer. was.

Continuous operation was carried out in this manner for 20 hours.

The amount of 2-chloropropionaldehyde produced per hour was approximately constant within a range of about ±5% from about 20 minutes after the start of operation.

Gas chromatographic analysis showed that about 55 g of 2-chloropropionaldehyde was produced on average over a 2-hour period.

Example 14 First reaction step contents: 48 mmol of rhodium chloride perfusate, 38 mmol of rhodium chloride, in a glass flask of about 5 lindres.
3 liters of 4 mmolSt luene was charged.

After raising the temperature to 80°C, a mixed gas of carbon monoxide and hydrogen was flowed at 5 liters/hour while stirring, and treatment was carried out for 3 hours. The resulting catalyst liquid remained homogeneous even after being cooled to room temperature.

Second Reaction Step Using the obtained catalyst solution, exactly the same operation as in the second reaction step of Example 14 was performed. Continuous operation was carried out in this manner for 10 hours. The amount of 2-chloropropionaldehyde produced per hour was approximately constant within a range of about ±5% from about 20 minutes after the start of operation. Analysis by gas chromatography showed that about 54 g of 2-chloropropionaldehyde was produced on average over a 2-hour period.

(Effects of the Invention) According to the method of the present invention, 2-chloropropionaldehyde can be produced with high selectivity at low temperature and low pressure using vinyl chloride, carbon monoxide, and hydrogen as raw materials. In particular, according to the method of the present invention, a wide range of types of rhodium compounds can be used, so it is possible to select one that is inexpensive and easily available.

Claims (4)

[Claims] (1) (a) a rhodium compound, (b) a trivalent organophosphorus compound or an oxide of a trivalent organophosphorus compound, and (c
) A first reaction step in which carbon monoxide or carbon monoxide and hydrogen are reacted in the presence of a water-insoluble or poorly soluble organic solvent to obtain a catalyst liquid; and in the presence of the catalyst liquid, vinyl chloride, A method for producing 2-chloropropionaldehyde, comprising a second reaction step of reacting carbon monoxide and hydrogen to obtain a reaction mixture containing 2-chloropropionaldehyde. (2) The manufacturing method according to claim 1, wherein the reaction in the second reaction step is carried out in the presence of an organic acid and/or a base. (3) The production method according to claim 1, wherein the second reaction step is carried out in the presence of water. (4) The manufacturing method according to claim 1, wherein the reaction in the second reaction step is carried out in the presence of an organic acid and/or base and water.