JPH0145A - Method for producing 2-chloropropionaldehyde - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of application on Wll) The present invention is directed to the production of 2-chloropropion using vinyl chloride, carbon monoxide, and hydrogen as raw materials according to the following reaction formula (1). This invention relates to a method for producing aldehydes.

2-Chloropropionaldehyde can be used as a useful intermediate for chemicals, agricultural medicines, etc.

(Prior art and problems to be solved by the invention) 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
HELVETICA CHIMICA
ACTA), Volume 48, No. 5, 115! Pages 1157-1157. All of these methods use cobalt carbonyl as a catalyst, and for example, according to the above-mentioned French Patent No. 1,397,779, the reaction temperature is 110°C.
The reaction was carried out for 90 minutes under the conditions of a reaction pressure of 200 atm, and a reaction result of 57.4% conversion of vinyl chloride and 86.2% selectivity of 2-chloropropionaldehyde was obtained. 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 160
In addition to requiring a high reaction pressure of ~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 desired product, 2-chloropropionaldehyde, is a thermally unstable substance, and at such reaction temperatures and times, a considerable proportion of it is consumed in successive reactions, and this treatment is necessary to reduce the reaction yield. The process is not reproducible, and furthermore, 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, causing a loss of catalyst strength. It also has the problem of hindering reuse.

The present inventors have proposed, for example, Japanese Unexamined Patent Publication No. 6
1-126046, JP-A-62-10038, JP-A-62-22738, etc., discovered a method of reacting vinyl chloride, carbon monoxide, and hydrogen in the presence of a rhodium compound and a base. ing. According to this method, compared to the conventional method using a cobalt carbonyl M medium, the reaction proceeds at a lower temperature and lower pressure, and sufficient selectivity to the target product can be obtained. In these methods, general 2P is used as a base in the presence or absence of water.
(R'R"R") (where P represents a phosphorus atom, R1
, R1゜R3 respectively 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 4 to 11. Combinations are preferably used. These pKas are 4 to 1
Among the nitrogen-containing compounds in 1, pyridine compounds, quinoline compounds, imidazole compounds, triazole compounds, morpholine compounds, etc. are particularly preferably used from the viewpoint of reaction results, etc. However, all of these bases are relatively expensive compounds. Therefore, for industrial use, it is necessary to install, for example, a recovery device for these in order to minimize the amount of loss. In addition, since these are highly reactive compounds, they will gradually wear out when used for a long time, so it is necessary to operate in a way that suppresses their loss as much as possible. However, these operating conditions are not necessarily favorable for the synthesis of 2-chloropropionaldehyde, and therefore, these exhaustion and the reaction at a point slightly deviating from the optimum synthesis conditions will result in less production of the desired product, 2-chloropropion. This problem has a considerable impact on the production cost of aldehydes. In addition, many pyridine compounds, quinoline compounds, and morpholine compounds have relatively low boiling points, but these are difficult to use when separating the reaction product 2-chloropropionaldehyde from the reaction solution by distillation. A small amount of 2-chloropropionaldehyde is mixed with low-boiling point 2-chloropropionaldehyde, resulting in a decrease in the purity of the product (2-chloropropionaldehyde is oxidized to produce 2-chloropropionic acid). It also has the problem of significantly inhibiting the oxidation reaction.

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

(Means and effects for solving the problems) The present inventors conducted detailed research to solve these problems. As a result, when producing 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, a guanidine compound The present inventors have discovered that if a weak acid salt thereof is allowed to coexist, the reaction can proceed efficiently and the problems of catalysts made of rhodium and a base as described above can be solved, and the present invention has been completed.

That is, in the presence of a rhodium compound and a trivalent organic phosphorus compound or an oxide of a trivalent organic phosphorus compound,
2-chloropropionaldehyde is produced by reacting vinyl chloride, carbon monoxide and hydrogen, the reaction being carried out in the coexistence of at least one guanidine compound or a weak acid salt thereof. This is the manufacturing method.

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

That is, as a trivalent organic phosphorus compound, general 2P (R'
R"R' ) (where P represents a phosphorus atom, R1, R
t and R3 are the same or different alkyl, aryl, cycloalkyl, alkoxy, aryloxy or cycloalkoxy groups, respectively), and specifically, trimethylphosphine, triethylphosphine, etc. , tripropylphosphine, tributylphosphine, trioctylphosphine,
Phosphines such as triphenylphosphine, tricyclohexylphosphine, tribenzylphosphine, trimethylphosphite, triethylphosphite, tripropylphosphite, tributylphosphite, trioctylphosphite, triphenylphosphite, tricyclohexylphosphite, Examples include phosphites such as benzyl phosphite.

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

In addition, as the oxide of the trivalent organic phosphorus compound, alkylphosphine oxide such as triethylphosphine oxide, tributylphosphine oxide, and trioctylphosphine oxide, arylphosphine oxide such as triphenylphosphine oxide and tritolylphosphine oxide, or an alkyl group and an aryl Examples include alkylarylphosphine oxide when combined with the group. In addition, alkyl or aryl phosphite oxides such as triethyl phosphite oxide, tributyl phosphite oxide, triphenyl phosphite oxide, and alkylaryl phosphite oxides having both an alkyl group and an aryl group can also be used. can. Furthermore, polydentate phosphine oxides such as bis-1,2-diphenylphosphinomethane dioxide and the like can also be used.

Further, specific examples of the guanidine compound or its weak acid salt are as follows. That is, in addition to guanidine, guanidine compounds include compounds in which at least one hydrogen attached to the amino group of guanidine is substituted with an alkyl group, cycloalkyl group, aryl group, alkylaryl group, amino group, or hydroxyalkyl group. Examples of these include l-methylguanidine, 1-ethylguanidine, 1-phenylguanidine, 1,1-dimethylguanidine, 1,3-diphenylguanidine, N-aminoguanidine, monomethylolguanidine, 1,3- Examples include dimethylolguanidine.

In addition, examples of weak acid salts of guanidine compounds include guanidine formate, guanidine acetate, guanidine propionate,
Examples include guanidine carboxylates such as guanidine butyrate, guanidine benzoate, monoguanidine phthalate, and diguanidine phthalate, and guanidine carbonates such as guanidine carbonate and guanidine hydrogen carbonate. Preferred examples also include triguanidine phosphate and diguanidine hydrogen phosphate. In addition, among these guanidine salts, salts of guanidine compounds using the various guanidine compounds mentioned above in place of guanidine are also preferably used, examples of which include 1-methylguanidine acetate, 1-ethylguanidine acetate, Examples include 1-phenylguanidine acetate, 1,1-dimethylguanidine benzoate, mono- or di-1,3-diphenylguanidine phthalic acid salt, and aminoguanidine acetate.

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, rhodium compounds that do not contain halogens are particularly preferred. Examples of these include rhodium oxide, rhodium nitrate, rhodium sulfate, rhodium acetate, rhodium triacetylacetonato, rhodium dicarbonylacetylacetonate, and rhodium dodeca. Examples include carbonyltetrarhodium, 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 base preferably used in the method of the present invention, but may also be other bases, such as hydridocarbonyltritriphenylphosphine rhodium (RhH(Co)(PPh)
i)i), nitrosyltristriphenylphosphine rhodium (Rh(No)(PPhz)s), η-cyclopentadienylbistriphenylphosphine rhodium (Rh(CsHs)(PPhi)z), and the like.

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. Addition of potassium oxide, potassium carbonate, trimethylamine, triethylamine, etc. can also be used as a means for producing a halogen-free rhodium compound in the reaction system.

In the method of the present invention, the rhodium compound is o, ooo as rhodium atoms per liter of liquid phase in the reaction system.
i~1000 milligram atoms, preferably 0.001
It is used in amounts corresponding to a range of ~100 milligram atoms. The base used in the method of the present invention is used in an amount of 0.1 to 500 mol, preferably 0.5 to 100 mol, per gram atom of rhodium.

In the method of the present invention, the reaction proceeds even without the use of a reaction solvent, but the reaction is usually carried out in the presence of a reaction solvent.As the reaction solvent, any solvent can be used as long as it does not adversely affect the reaction. Is possible. Hydrocarbons are particularly preferred as such solvents. More specifically, hexane, heptane, octane, nonane, decane, etc. 17) I[1 hydrocarbons, benzene, toluene,
Aromatic hydrocarbons such as xylene are preferably used,
These examples also include ligroin, kerosene, light oil, diesel oil, etc., which are industrially obtained as mixtures of hydrocarbons. In addition, examples of preferred solvents include ethers such as dipropyl ether and dibutyl ether, ketones such as diisobutyl ketone and holon, and esters such as butyl butyrate and butyl benzoate.

In the method of the present invention, a method in which water is allowed to coexist in the reaction system is more preferably carried out. By adopting such a method, the catalytic activity is further improved.

There is no particular limit to the amount of water present during the reaction in the method of the present invention, but if it is used in an extremely small amount, the effect will be small, and even if it is used in an extremely large amount, the reaction results will not improve beyond a certain level. Usually, the amount of water is preferably in the range of 0.01 or more and 1000 or less, particularly 0.1 to 1, in terms of weight ratio to the vinyl chloride supplied to the reactor as a raw material.
A range of 00 is more preferably used.

When carrying out the method of the present invention, other components such as additives to improve the stability of the rhodium catalyst, additives to improve the activity and selectivity of the catalyst, such as carboxylic acids, etc., may be added to the reaction system. There is no particular problem even if they coexist.

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/cj gauge, preferably 30 to 150 kg/cj gauge. Low temperature is preferable from the viewpoint of thermal stability of 20 to 80
℃ is a particularly preferred temperature range. Further, the mixing molar ratio of raw materials carbon monoxide and hydrogen is usually in the range of 10 to 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. 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 for the reaction. For example, in the case of a batch method, a rhodium compound, a trivalent organic phosphorus compound or an oxide of a trivalent organic phosphorus compound, a guanidine compound or its weak acid salt, and if necessary a reaction solvent and Vinyl chloride is added in the form of a gas, liquid, or solution to an autoclave filled with water, and a gas containing carbon monoxide and hydrogen is introduced to the autoclave to a predetermined pressure, and the reaction is carried out by heating, preferably with stirring. progresses. In addition, as an example of a continuous method, a rhodium compound, a trivalent organic phosphorus compound or an oxide of a trivalent organic phosphorus compound, a guanidine compound or its weak acid salt, and if necessary a reaction solvent and water, and the raw material Vinyl chloride, carbon monoxide and hydrogen are continuously fed into one side of a pressure-resistant reactor, and the reaction mixture and unreacted vinyl chloride, carbon monoxide and hydrogen are fed from the other side under stirring conditions at reaction temperature. The reaction is carried out by continuously withdrawing .

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

Example 1 After purging the inside of a stainless steel autoclave with an internal volume of 100 d and equipped with a stirring device with nitrogen gas, 36 mm of hexadecacarbonyl hexalodium (0.2 milligram atoms of Rh) and 157 mm of triphenylphosphine (0.6 mmol) were added. ), 119 μg (1 mmol) of guanidine acetate and 20 g of water were added, and 1.88 g (3 mmol) of vinyl chloride was added thereto.
20 mmoles of a toluene solution of hinyl chloride containing 0 mmol) was 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 80 kg/m at room temperature.
After press-fitting until it reaches C-gauge, the temperature is raised to 60℃,
The reaction was allowed to proceed 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 15.5%, and the amount of 2-chloropropionaldehyde produced was 4.2 mmol (selectivity based on converted vinyl chloride was 90.3%). )Met.

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.

(Left below) Examples 6 to 9 In the method of Example 1, the reaction was carried out at a reaction temperature of 50°C and with different types of rhodium compound and base. The amount of rhodium compound was set to 0.2 milligram atom of rhodium in each case. The results are shown in Table 2.

Example 10 The reaction was carried out in the same manner as in Example 1 except for the absence of water.

As a result of the analysis, reaction results were obtained with a vinyl chloride conversion rate of 3.1% and a 2-chloropropionaldehyde selectivity of 90.1%.

(Effects of the Invention) According to the present invention, 2-chloropropionaldehyde can be produced in high yield at low temperature and low pressure using vinyl chloride, carbon monoxide, and hydrogen as raw materials. In particular, unlike conventional methods, the method of the present invention does not require equipment for recovering the base or removing the base mixed in 2-chloropropionaldehyde, and the conditions must be selected to suppress the loss of base as much as possible. It becomes possible to proceed with the reaction stably over a long period of time using a simple device.

Patent applicant: Mitsui Toatsu Chemical Co., Ltd.

Claims (3)

[Claims] (1) In producing 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 phosphorous compound, the reaction is carried out. A method for producing 2-chloropropionaldehyde, which is carried out in the coexistence of at least one guanidine compound or a weak acid salt thereof. (2) The method according to claim 1, wherein the reaction is carried out in the presence of water. (3) The method according to claim 1 or 2, wherein the reaction is carried out at a temperature in the range of 20 to 80°C.