JPS6210038A - Production of 2-chloropropionaldehyde - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as an intermediate for chemicals, in high selectivity, by reacting vinyl chloride with CO and H2 at low temperature under low pressure in the presence of a catalyst consisting of a rhodium compound having high catalytic activity and a specific base. CONSTITUTION:The objective compound can be produced by reacting vinyl chloride with CO and H2 preferably in a solvent especially preferably at 20-100 deg.C and 30-150kg/cm<2> gauge pressure, in the presence of a catalyst consisting of a combination of (A) a rhodium compound preferably free from halogen, e.g. the compound of formula RhH(CO)(Ph3P)3, etc., and (B) a base consisting of (i) at least one kind of the compound of formula (P is phosphorus; R<1>-R<3> are alkyl, acyl, cycloalkyl, etc.) and (ii) at least one kind of a nitrogen- containing compound having a pka of 4-10 such as morpholine (excluding pyridine, quinoline and imidazole compounds). EFFECT:There is little by-production of HCl and low corrosion of the reactor material. The catalyst can be reused easily.

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. 2-Chloropropionaldehyde can be used as a useful intermediate in chemicals and agropharmaceuticals.

(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. 1,397,779 and Helvetica Patent No.
Kimica O Acta (HKLITICA OH Engineering CAA)
CTA), Vol. 48, No. 5, pp. 1151-1157. All of these methods use cobalt carbonyl as a catalyst, and for example, according to the French Patent No. 1.39 Suf 79, the reaction is carried out for 90 minutes at a reaction temperature of 110°C and a reaction pressure of 200 atm. The reaction results were 57.4% conversion of vinyl chloride and 86.2% selectivity of 2-chloropropionaldehyde.

(Problems to be Solved by the Invention) However, in these methods using cobalt carbonyl as a catalyst, the catalytic activity per cobalt is extremely low;
For this purpose, a large amount of cobalt carbonyl and 160-200
In addition to requiring a high reaction pressure of atmospheric pressure, the reaction temperature is 7.
A method is used in which the reaction is carried out at 5 to 125°C for 90 to 120 minutes. The desired product, 2-
Chloropropionaldehyde is a thermally unstable substance.
Under such reaction temperature and reaction time, a considerable proportion is consumed by the sequential reactions, lowering the reaction yield, and hydrogen chloride is produced as a by-product by the sequential reactions or other side reactions. In addition to severely corroding the material of the reactor, it also reacts with the cobalt carbonyl catalyst to form cobalt chloride, which poses a problem in that it impedes the reuse of the catalyst.

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

(Means for Solving the Problems) The present inventors conducted detailed research to solve these problems. As a result, when vinyl chloride, carbon monoxide, and hydrogen are reacted in the presence of a catalyst consisting of a combination of a rhodium compound and a specific base, the reaction proceeds at lower temperatures and pressures than with conventional cobalt catalysts. They have also found that sufficient selectivity to the desired product can be obtained, leading to the present invention.

That is, the present invention involves synthesizing 2-chloropropionaldehyde by reacting vinyl chloride, carbon monoxide, and hydrogen in the presence of a rhodium compound and a base.
As a base, (1) General formula P (R" 12R3) (wherein, P
is a phosphorus atom, and R1, R2, and R3 each represent an alkyl group, an aryl group, a cycloalkyl group, an alkoxy group, an aryloxy group, or a cycloalkoxy group; and (2) at least one compound having a pKa of , 4 to 10 (excluding pyridine compounds, quinoline compounds, imidazole compounds, or triazole compounds).

In the method of the present invention, in addition to using a rhodium compound as a catalyst, it is necessary to use a specific combination of bases as described in (1) and (2) above as a cocatalyst. In the absence of these bases, rhodium compounds do not catalyze this reaction.

Specific examples of these bases are as follows. That is, the general formula P(R1R2R3) (wherein, P is a phosphorus atom, R1, R2 and R3 are each an alkyl group,
Examples of compounds represented by aryl group, cycloalkyl group, alkoxy group, aryloxy group or cycloalkoxy group include trimethylphosphine, triethylphosphine, tripropylphosphine, tributylphosphine, trioctylphosphine, triphenylphosphine, tricyclohexyl Phosphines such as phosphine, tribenzylphosphine, bisdiphenylphosphinoethane, trimethylphosphite, triethylphosphite, tripropylphosphite, tributylphosphite, trioctylphosphite, triphenylphosphite, tricyclohexylphosphite, Examples include phosphites such as benzyl phosphite.

In addition, pKa is 4 to 4, excluding pyridine compounds, quinoline compounds, imidazole compounds, or triazole compounds.
Examples of nitrogen-containing compounds in the range of 10 include aniline, methylaniline, diethylaniline, o-)luidine, m
-) Aromatic amines such as luidine, p-toluidine, and 2-naphthylamine, diamines such as ethylenediamine and 1,2-propanediamine, α-amino alcohols such as monoethanolamine and triethanolamine, ethyl biroline, N - Cyclic amines such as phenylpyrrolidine, morpholine, N-methylmorpholine or 1dN
- Morpholine compounds such as ditylmorpholine are preferred, and in addition, ammonia, benzylamine, adenine,
Nitrogen-containing compounds such as cytosine and triphenylguanidine are also preferably used.

In particular, among these nitrogen-containing compounds, morpholine, N
- Morpholine compounds such as methylmorpholine or N-ethylmorpholine are preferred.

Examples of the rhodium compound used in the method of the present invention include rhodium oxides, mineral acid salts, organic acid salts, and rhodium complex compounds. Among these various rhodium compounds, halogen-free rhodium compounds are particularly preferred. Examples of these are rhodium oxide, rhodium nitrate,
Examples include rhodium sulfate, rhodium acetate, rhodium trisacetylacetonate, rhodium dicarbonylacetylacetonate, rhodium dodecacarbonyl tetrarhodium, and rhodium hexadecacarbonyl hexadecacarbonyl.

In addition, a halogen-containing rhodium compound such as rhodium chloride, rhodium bromide, rhodium iodide, or dichlorotetracarbonyl dirhodium is used, and an alkaline compound such as sodium hydroxide, water, etc. You can also add potassium oxide, potassium carbonate, trimethylamine, triethylamine, etc.
It can be used as a means for producing a rhodium compound that does not contain halogen in the reaction system.

In addition, the above-mentioned base and rhodium compound preferably used in the method of the present invention may also be a complex compound.
More preferably used. Examples of these include, for example, hydridocarbonyltristriphenylphosphine rhodium (RhH((!0)(Ph3F) 3), nitrosyltristriphenylphosphine rhodium (Rh<
No) (Ph3F)3), η-cyclopentadienylbistriphenylphosphine rhodium (Rh(C5
H5)(Ph3P)2) and the like.

Although the method of the present invention can be carried out without the use of a solvent, it is usually carried out in the presence of a solvent. The solvent is usually a saturated hydrocarbon such as heptane, hexane, octane, decane, or dodecane, an aromatic hydrocarbon such as benzene, toluene, or xylene, or a halogenated hydrocarbon such as monochlorobenzene, orthodichlorobenzene, or parachlorotoluene. , alcohols such as methanol, ethanol, propatool, butanol, pentanol, and octatool, esters such as butyl acetate and γ-butyrolactone, ethers such as tetrahydrofuran, ethylene glycol dimethyl ether, diglyme, and tetraglyme, acetone, methyl Ketones such as isobutyl ketone, aldehydes such as propionaldehyde and butyraldehyde, acid anhydrides such as acetic anhydride, nitriles such as acetonitrile and propionitrile, amides such as N-methylpyrrolidone, dimethylimidazolidinone, tetra Ureas such as methylurea, carbonate esters such as ethylene carbonate and propylene carbonate, etc. are used.

In the method of the present invention, the rhodium compound contains 10-' to 10-10 rhodium atoms per mole of raw material vinyl chloride.
It is used in an amount corresponding to 3 milligram atoms, preferably in the range from 0.1 to 50 milligram atoms. Furthermore, the bases used in the method of the present invention each include rhodium 1
0.1 to 500 mol, preferably 0.1 to 500 mol per gram atom.
It is used in a range of 5 to 100 moles.

The method of the present invention usually has a reaction temperature in the range of 20 to 150 °C, a reaction pressure in the range of 10 to 200 Kg/ctrl gauge,
It is preferably carried out in the range of 30 to 150 kg/crIi gauge.

From the viewpoint of thermal stability of the produced 2-chloropropionaldehyde, a low reaction temperature is preferable;
-100°C is a particularly preferred reaction temperature range. Also,
The mixing molar ratio of raw material carbon monoxide and hydrogen is usually 10 to
It is in the range of 0.1, preferably in the range of 4 to 0.2. Carbon monoxide and hydrogen may be mixed gases containing both components in the above-mentioned composition ratio, such as aqueous gas, a gas inert to the reaction such as methane or nitrogen, or carbon dioxide or moisture. is used.

The other raw material, vinyl chloride, is used in the form of a gas, liquid, or solution dissolved in the solvent used for 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, vinyl chloride gas, liquid, or solution is added to an autoclave containing a catalyst and, if necessary, a solvent, and then a gas containing carbon monoxide and hydrogen is introduced to a predetermined pressure. The reaction progresses by heating. In the case of a continuous method, a liquid consisting of a catalyst, vinyl chloride, and if necessary a solvent, and a gas containing carbon monoxide and hydrogen are continuously introduced into one side of a pressure-resistant reactor, and the reaction is carried out from the other side. The reaction is carried out by continuously withdrawing a liquid consisting of the product, catalyst, unreacted vinyl chloride, and optionally a solvent, as well as unreacted carbon monoxide and hydrogen. Vinyl chloride can also be introduced into the reaction vessel in gaseous form together with a mixed gas containing raw materials carbon monoxide and hydrogen.

In addition, as a modification of the continuous method, a catalyst and, if necessary, a solvent are charged into a reactor, and the raw materials vinyl chloride, carbon monoxide, and hydrogen are continuously introduced from the bottom of the reactor, and then from the top. A method of continuously extracting unreacted vinyl chloride, carbon monoxide, hydrogen, and reaction products can also be used.

(Function and Effects of the Invention) The method of the present invention has higher catalytic activity than conventional cobalt catalysts, so the reaction can be carried out at low temperatures and in a short time. There is little loss of chloropropionaldehyde due to sequential reactions, and high selectivity can be obtained. Furthermore, since there is little hydrogen chloride by-product due to this sequential reaction or other side reactions, there is little corrosion of reactor materials, and the catalyst can be easily reused.

Furthermore, the method of the present invention is advantageous in terms of the pressure resistance of the reactor and the power required to compress the raw materials carbon monoxide and hydrogen, since the reaction proceeds under relatively low pressure.

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

Example 1 After replacing the inside of a stainless steel autoclave with an internal volume of 50 m/m equipped with a stirring device with nitrogen gas, hydridocarbonyltristriphenylphosphine rhodium 184
rn9 (Rh 0.2 mg atom) and morpholine 2
18 m9 (2.5 mmol) of vinyl chloride was added thereto, and 20 ml of a toluene solution of vinyl chloride containing 3.75 f (60 mmol) of vinyl chloride was added thereto. In this autoclave,
A mixed gas with a molar ratio of carbon monoxide and hydrogen of 1:2 has a pressure of 75 Kg/cr at room temperature! After press-fitting until the gauge was reached, the temperature was raised to 40° C. and reacted for 120 minutes. After the autoclave was cooled to room temperature and the 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 19.9%, 2
-The amount of chloropropionaldehyde produced was 10.9 mmol (selectivity based on converted vinyl chloride was 916%), and propionaldehyde was the main by-product with a selectivity of 4.9 mmol.
It was confirmed that it was generated in 8 chis.

Examples 2 to 5 Reactions were conducted in the method of Example 1 by changing the reaction temperature, reaction pressure, molar ratio of carbon monoxide to hydrogen, and reaction time.

The results are shown in Table 1.

Table 1 Examples 6 to 8 In the method of Example 1, the reaction was carried out by changing the amounts of rhodium hydridocarponyltristriphenylphosphine and morpholine added.

The results are shown in Table 2.

Table 2 Examples 9 to 14 In the method of Example 1, the reaction temperature was set to 50° C., and the reaction was carried out for 30 minutes using various bases instead of morpholine.

The results are shown in Table 3.

Table 3 Examples 15 to 18 In the method of Example 1, the reaction was carried out using various solvents instead of toluene.

The results are shown in Table 4.

Table 4 Example 19 In the method of Example 1, the reaction temperature was 80°C, and instead of hydridocarbonyltristriphenylphosphine rhodium, hexadecacarbonylhexalodium! l6
The reaction was carried out using rruj and triphenylphosphine/157m9. Analysis of the gas and liquid revealed reaction results of a conversion rate of vinyl chloride of 23.1% and a selectivity of 2-chloropropionaldehyde of 904%.

Example 20 In the method of Example 19, the reaction was carried out using dodecacarbonyltetrarhodium 571n9 instead of hexadecacarbonylhexalodium.

From gas and liquid analysis, the conversion rate of vinyl chloride was 14.2.
%, selectivity of 2-chloropropionaldehyde 91.
A reaction result of 3% was obtained.

Example 21 The reaction was carried out in the same manner as in Example 19, using dicarbonylacetylacetonate rhodium 52 lbs instead of hexadecacarbonylhexalodium. Analysis of the gas and liquid revealed reaction results of 195% conversion of vinyl chloride and 91B selectivity of 2-chloropropionaldehyde.

Example 22 In the method of Example 19, the reaction was carried out using 121 g of tri-butylphosphine in the reaction of triphenylphosphine. Analysis of the gas and liquid revealed reaction results of a conversion rate of vinyl chloride of 11.4% and a selectivity of 2-chloropropionaldehyde of 87.5%.

Example 23 In the method of Example 19, the reaction was carried out using tricyclohexylphosphine 168rn9 instead of triphenylphosphine. Analysis of the gas and liquid revealed reaction results of 12.1% conversion of vinyl chloride and 83.6% selectivity of 2-chloropropionaldehyde.

Example 24 In the method of Example 19, the reaction was carried out using 249 ml of triethyl phosphite instead of triphenylphosphine. Analysis of the gas and liquid revealed reaction results of a conversion of vinyl chloride of 13.1% and a selectivity of 2-chloropropionaldehyde of 892%.

Reference Example 1 In the method of Example 1, hexadecacarbonylhexalodium 36rn9 was used as a substitute for hydridocarbonyltristriphenylphosphine rhodium, and the reaction was carried out in the absence of morpholine.

No production of 2-chloropropionaldehyde was observed in the autoclave after the reaction.

Reference Example 2 In the method of Reference Example 1, octacarbonyl dicobalt 224 was used instead of hexadecacarbonylhexalodium.
The reaction was carried out using (2).

After the reaction, only traces of 2-chloropropionaldehyde were observed in the autoclave.

Claims (1)

[Claims] 1) In synthesizing 2-chloropropionaldehyde by reacting vinyl chloride, carbon monoxide and hydrogen in the presence of a rhodium compound and a base, (1) a compound of the general formula P(R ^1R^2R^3) (wherein, P is a phosphorus atom, and R^1, R^2 and R^3 are each,
(2) a nitrogen-containing compound having a pKa in the range of 4 to 10;
However, the method for producing 2-chloropropionaldehyde is characterized in that at least one of the following is used (excluding pyridine compounds, quinoline compounds, imidazole compounds, and triazole compounds). 2) The method according to claim 1, wherein the rhodium compound is a halogen-free rhodium compound. 3) The method according to claims 1 and 2, wherein the nitrogen-containing compound having a pKa in the range of 4 to 10 is a morpholine compound. 4) The method according to claims 1 to 3, wherein the reaction temperature is in the range of 20 to 100°C.