JPS638099B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a novel intermediate product produced in a novel method for producing chloropyridines substituted with a methyl group, a trichloromethyl group, or a trifluoromethyl group, and It relates to its manufacturing method.

[Conventional technology]

Chlorpyridines substituted with a methyl group, trichloromethyl group or trifluoromethyl group are
Conventionally, they were manufactured only by methods that required multiple steps. For example, 2,5-dichloro-3-methylpyridine and 2,3-dichloro-5-methylpyridine are each 2-chloro-3-methyl-5-methylpyridine.
It was produced by diazotizing -aminopyridine or 2-chloro-3-amino-5-methylpyridine and substituting it with chlorine while decomposing it.

The above aminopyridine is obtained by chlorinating 3-methylpyridine to give 2-chloro-3-methylpyridine and 2-chloro-5-methylpyridine, and by nitration, converting these into 2-chloro-3-methyl-5-
Nitropyridine and 2-chloro-3-nitro-
It can be produced by reducing a nitro compound to 5-methylpyridine. Chlorination of 3-methylpyridine usually produces a number of isomers in addition to the desired compound. By chlorination of 2,3-dichloro-5-methylpyridine, 2,3-
Dichloro-5-trichloromethylpyridine can be obtained and converted to 2,3-dichloro-5-trifluoromethylpyridine by replacing the chlorine atom of the trichloromethyl group with a fluorine atom (for example, as described in European Patent Publication No. (See No. 004414). Also,
By heating 2,4-dimethylpyrrole and chloroform in the gas phase at a temperature of about 550°C, 2-
Chloro-3,5-dimethylpyridine is obtained together with five other isomers [J.Chem.Soe.Perkin
Trans. I, 1578-82 (1979)].

[Means to solve problems]

Now here is the following formula (In the formula, R is chlorine and R ² is a methyl or trifluoromethyl group, or R is a methyl, trichloromethyl or trifluoromethyl group and R ²
represents a methyl group, or R and R ² represent a methyl group. It has been found that the chlorpyridines represented by the following formula can be produced in good yields by a simple, economical and environmentally friendly method using readily available and inexpensive raw materials.

That is, in the presence of a catalyst, (a) trichloroacetaldehyde to methylacrylonitrile or α-trifluoromethylacrylonitrile, (b) 2,2-dichloropropionaldehyde, pentachloropropionaldehyde or 2.
By adding 2-dichloro-3,3,3-trifluoropropionaldehyde to acrylonitrile, or (c) 2,2-dichloropropionaldehyde to methacrylonitrile, the following formula is obtained. (In the formula, R is chlorine and R ¹ is a methyl or trifluoromethyl group, or R is a methyl, trichloromethyl or trifluoromethyl group and R ¹
represents hydrogen, or R and R ¹ represent a methyl group. ) The intermediate product represented by the formula is produced, and by cyclizing the compound of this formula, the chlorpyridines represented by the formula can be produced.

A formally identical reaction to obtain 2,3,5-trichloropyridine from non-alkyl-substituted trichloroformbutynitrile has been published in European Patent Publication No.
Described in No. 12117. However, formylbutyronitrile of the formula substituted by a chlorinated methyl group or trihalogenated methyl group is cyclized to a chlorinated methyl group or trihalogenated methylpyridine of the formula while being aromatized. That could not have been predicted. This is because by the method of the invention it is no longer possible to obtain a methyl or trihalogenated methyl group on the ring and perform the elimination of water necessary for aromatization. Therefore, the expected product was rather a 2-pidrine derivative. Therefore, the results of the present invention can be said to be very surprising. The formation of an addition compound of the formula from 2,2-dichloro-propionaldehyde, perchlor- or 2,2-dichloro-3,3,3-trifluoroproionaldehyde also shows that the reactivity of trichloroacetaldehyde is different from that of its congeners. very different [e.g. Chem.Ber., 97 , 3322
(1964)], which is surprising, especially since the mobility of chlorine in chloroacetaldehyde is considerably limited by other hydrocarbon substituents such as methyl, trichloromethyl or trifluoromethyl.

[Preferred mode for carrying out the invention]

Among the compounds of the formula according to the invention, particularly preferred are those in which R is chlorine and R ¹ is a methyl group, or R is trifluoromethyl, trichloromethyl or a methyl group and R ¹ is hydrogen.

The process for preparing compounds of the formula according to the invention is carried out in an open or closed system, preferably at a temperature of 70-160°C. Preferably, it is carried out in a closed system under a pressure corresponding to the reaction temperature, for example in the range from 1 to 30 bar.

Catalysts for the reaction in the process of the invention include metals of the main group and subgroups a, a, b and b of the periodic table, such as iron, cobalt, nickel, ruthenium, bardium, chromium, molybdenum, manganese, copper. and zinc can be used. These metals can be used both in their elemental state and in their compound state. A suitable compound is
For example, oxides and salts such as halides, sulfates, sulfites, sulfides, nitrates, acetates, steriaphosphates, citrates, carbonates, cyanides, rhodanides, as well as phosphines, phosphites, etc. They are complexes with ligands such as acid salts), benzoylacetone, acetylacetone, nitriles, isonitriles, and carbon monoxide.

Typical examples include:
Copper() oxide, iron() oxide; copper()−,
Copper () −, iron () − and iron () bromide, −
Iodides and especially - chlorides, zinc chloride and chlorides of ruthenium, rhodium, palladium, cobalt and nickel; copper () sulphates, iron () - and iron () sulphates; copper () nitrates and iron () Nitrate; manganese () acetate, copper () acetate, copper () steriaphosphate, iron () citrate, copper () cyanide; ruthenium ()-dichloro-tris-triphenylphosphine, rhodium-dichloro -tris-triphenylphosphine; chromium- and nickel acetylacetonate; copper ()-acetylacetonate; iron ()-acetylacetonate; cobalt ()- and cobalt ()-acetylacetonate; manganese ()-acetylacetonate; Copper()benzoylacetonate; iron carbonyl-
Cyclopentadienyl complexes; molybdenum carbonyl cyclopentadienyl complexes, chromium tricarbonyl aryl complexes, ruthenium ()-acetate complexes, chromium- and molybdenum hexacarbonyls, nickel tetracarbonyls, iron pentacarbonyls, cobalt- and manganese carbonyls.

Mixtures of the above-mentioned metals with metal compounds and/or other additives, such as combinations of copper powder and one of the above-mentioned copper compounds; copper powder and lithium halides (such as lithium chloride) or isocyanides (tert-
(butyl isocyanide, etc.); mixtures of iron powder and iron() chloride, sometimes with the addition of carbon monoxide; mixtures of iron() chloride and benzoin; iron()- or iron () Mixtures of chlorides and trialkyl phosphites; mixtures of iron pentacarbonyl and iodine can also be used.

Preference is given to iron() and iron() salts and complexes, in particular iron()- and iron() chlorides, and iron powder; ruthenium() chloride, ruthenium() dichloro-tris-triphenylphosphine. , copper powder, bronze, copper() and copper() salts and complexes, such as copper() chloride,
Copper () chloride, copper () bromide, copper () bromide, copper () acetate, copper () acetylacetonate, copper () benzoylacetonate, copper () sulfate, copper () nitrate, copper () cyanide and copper() iodide.

Particularly preferred are copper powder, bronze, copper ()- and copper () chloride or -bromide and copper ()
iodide, as well as mixtures thereof.

The catalyst usually has a concentration of about 0.01 to aldehydes.
It is used in an amount of 10 mol%, preferably 0.1-5 mol%.

The addition of aldehydes to acrylonitrile, methacrylonitrile or α-trifluoromethyl-acrylonitrile in the method of the invention is preferably carried out in the presence of an inert organic solvent. Suitable solvents are those in which the catalyst is sufficiently soluble or capable of forming a complex with the catalyst, and is inert to the reaction components. Examples of suitable solvents include: Alkanecarboxylic acid nitriles, especially those having 2 to 5 carbon atoms, such as acetonitrile,
Propionitrile and butyronitrile; 3-alkoxypropionitriles in which the alkoxy group has 1 to 2 carbon atoms, such as 3-ethoxypropionitrile and 3-ethoxypropionitrile; aromatic nitriles, especially benzonitrile; preferably carbon Aliphatic ketones with 3 to 8 atoms, such as acetone, diethyl ketone, methyl isopropyl ketone, diisopropyl ketone, methyl tert-butyl ketone; alkoxy- and alkoxyalkyl esters of aliphatic monocarboxylic acids with 2 to 6 carbon atoms , for example methyl formate and -ethyl ester, methyl acetate, -ethyl-, -n-butyl-
and -isobutyl esters and 1-acetoxy-2-methoxyethane; cyclic ethers, such as tetrahydrofuran, tetrahydropyran and dioxane; dialkyl ethers in which the alkyl group has in each case 1 to 4 carbon atoms, such as diethyl ether, di-n-propyl ether and diisopropyl ether; the number of carbon atoms in the alkyl group is 1
N·N-dialkylamide of an alkanecarboxylic acid of ~3, such as N·N-dimethylformamide,
N·N-dimethylacetamide, N·N-diethylacetamide and N·N-dimethylmethoxyacetamide; ethylene glycol and diethylene glycol dialkyl ethers in which the alkyl group has 1 to 4 carbon atoms, for example ethylene glycol dimethyl-, -diethyl -and-
di-n-butyl-ether; diethylene glycol diethyl- and -di-n-butyl ether;
Phosphoric acid tris-N.N-dimethylamide (Hexa-metapol). Furthermore, excess acrylonitrile, methacrylonitrile or α-
Trifluoromethyl-acrylonitrile can also be used as a solvent.

Preferred solvents include alkanecarboxylic acid nitriles having 2 to 5 carbon atoms, 3-alkoxypropionitriles in which the alkyl group has 1 to 2 carbon atoms, acetonitrile, butyronitrile and
-methoxypropionitrile or unsaturated nitriles used as reaction components.

As mentioned above, the compound of the formula is an intermediate compound in obtaining the chlorpyridines of the formula, but the reaction of cyclizing the compound of the formula to produce the chlorpyridines of the formula can be carried out in an open or closed system in about 0～
It is carried out at a temperature of 220°C, especially about 100-200°C. Preferably the cyclization is carried out in an open system. During the cyclization in the open system, the presence of hydrogen chloride or substances that form hydrogen chloride under the reaction conditions, such as phosgene, boron trichloride, aluminum chloride, and alkyl groups each having 1 to 4 carbon atoms, are used. Conveniently it is carried out in the presence of trialkylammonium chloride, phosphorus pentachloride, phosphorus oxychloride or phosphorus trichloride. Preferably the cyclization is carried out in the presence of hydrogen chloride. The cyclization reaction is preferably carried out by simply heating the compound of the formula in the liquid or gas phase without the addition of a solvent. However, it is also possible to carry out the reduction in the presence of an organic solvent. Organic solvents include in particular chlorinated aliphatic hydrocarbons such as chloroform, methylene chloride and tetrachloroethane; optionally chlorinated aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; carbon atoms N·N-dialkylamides of alkanecarboxylic acids of numbers 1 to 3, such as N·N-dimethylformamide, N·N-dimethylacetamide, N·N-diethylacetamide and N·N
-dimethylmethoxyacetamide; cyclic amide;
For example, N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone and N-methyl-ε-caprolactam; amides of carbonic acids, such as tetramethylurea and dimorpholinocarbonyl; phosphorous acid,
Amides of phosphoric acid, phenylphosphonic acid or alkylsulfonic acids in which the alkyl group has 1 to 3 carbon atoms, such as phosphoric triamide, phosphoric acid tris-(N·N-dimethylamide), phosphoric acid trimorpholide, phosphoric acid tripyrrolinide , phosphorous acid-tris-(N·N-dimethylamide)methanephosphonic acid-bis-(N·N-dimethylamide); amides of sulfuric acid or aliphatic or aromatic sulfonic acids, such as tetramethylsulfamide; methanesulfonic acid dimethylamide or p-toluenesulfonic acid amide; aliphatic ketones, cyclic ethers, dialkyl ethers of the type mentioned above, and ethylene glycol- and diethylene glycol ethers,
and phosphorus trichloride and phosphorus oxychloride.

Preferred solvents for the cyclization reaction are chloroform, methylene chloride, cyclic ethers and diethyl ether in which the alkyl group has 1 to 4 carbon atoms, in particular dioxane and diethyl ether,
and N.N-dialkylamides of alkanecarboxylic acids having 1 to 3 carbon atoms, especially N.N-methylformamide.

The preparation of chlorpyridines of the formula can be advantageously carried out by first isolating the compound of the formula obtained by the process of the invention and then cyclizing it in a second reaction step. In this case, the individual reaction steps are carried out as described above.

According to a preferred embodiment of the process for preparing chlorpyridines of the formula, the aforementioned aldehydes are prepared in a closed system in acetonitrile, butyronitrile or 3-methoxypropionitrile as a solvent at a temperature of 70 to 160°C. Copper powder, bronze, copper ()
or with acrylonitrile, methacrylonitrile or α-trifluoromethylacrylonitrile in the presence of 0.1 to 5 mol% of copper () chloride or bromide, or copper () iodide, or a mixture of these substances, After separation of the solvent, the compound of the formula obtained was heated at 100-200℃ in an open system.
cyclization in the presence of hydrogen chloride or a substance that forms hydrogen chloride under the reaction conditions at a temperature of .

However, it is also possible to carry out the addition reaction and the cyclization reaction in one operation without isolating the intermediate product of the formula according to the invention. In this case, the reaction of the above-mentioned aldehyde and acrylonitrile, methacrylonitrile or α-trifluoromethyl-acrylonitrile to obtain the chlorpyridine of formula 70
Preferably it is carried out at a temperature of ~220°C, especially 130-200°C. At this time, either an open system or a closed system can be used. When the reaction is carried out in an open system,
It is preferred to carry out the reaction in the presence of hydrogen chloride or in the presence of a substance that forms hydrogen chloride under the reaction conditions. Such substances include, for example, phosgene, boron trichloride, aluminum chloride, trialkylammonium chloride in which the alkyl group has 1 to 4 carbon atoms, respectively;
Phosphorus pentachloride, phosphorus oxychloride or phosphorus trichloride. The one-stage preparation of chlorpyridine of the formula is preferably carried out in a closed system under a pressure corresponding to the reaction temperature at hand, ie in the range for example from 1 to 50 bar. Particular preference is given to carrying out the synthesis of the compounds of the formula in one step in a closed system under a pressure of 1 to 30 bar.

This one-step synthesis is also conveniently carried out in the presence of the catalyst used in the process of the invention described above and in the presence of an inert organic solvent. Catalysts and solvents include those of the types previously described in connection with preferred catalysts and catalyst amounts.

Preferred solvents when carrying out a one-step synthesis are alkanecarboxylic acid nitriles having 2 to 5 carbon atoms and 3-alkoxypropionitriles having 1 to 2 carbon atoms in the alkyl group. Particularly suitable solvents are acetonitrile, butyronitrile and 3-
Methoxypropionitrile or excess unsaturated nitrile used as a reaction component. After the reaction has ended, the chlorpyridine of the formula can be isolated by conventional methods, for example by distilling off the solvent and distilling the crude product, or optionally by steam distillation.

According to a further advantageous embodiment for preparing chlorpyridines of the formula, the aldehyde and acrylonitrile, methacrylonitrile or α-trifluoromethylacrylonitrile are combined in a closed system with copper in the solvent acetonitrile, butyronitrile or 3-methoxypropionitrile. powder, bronze, copper() or chloride or bromide of copper(), or iodide of copper(), or a mixture of these substances, in the presence of 0.1 to 5 mol%, at 130 to 200 °C, then reaction Direct reaction under pressure corresponding to temperature gives chlorpyridines of the formula.

2,2-dichloro-3, used as raw material
3,3-Trifluoropropionaldehyde is a new substance and has been used in the synthesis of 4-formyl-2,4-dichloro-5,5,5-trifluorovaleronitrile and 2,3-dichloro-5-trifluoromethylpyridine. used.

2,2-dichloro-3,3,3-trifluoropropionaldehyde is obtained by treating the corresponding olefin with ozone and reductively treating the reaction product.

The following are used as solvents for this reaction: organic acids such as formic acid, acetic acid, propionic acid;
Esters of these acids, such as ethyl acetate, methyl acetate, ethyl formate,
Formic acid methyl ester; aliphatic hydrocarbons such as pentane, hexane, heptane, octane, cyclopentane, cyclohexane; chlorinated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride;
water.

The reaction temperature depends on the nature of the solvent, but ranges from -90℃ to +
70°C, preferably -70°C to +30°C.

Reductive treatment of ozone decomposition products can be carried out by direct catalytic hydrogenation using hydrogen and optionally noble metal catalysts such as platinum, palladium, rhodium adsorbed on a support, or by direct catalytic hydrogenation using a reducing agent such as zinc or dimethyl sulfide. This can be done by adding

One preferred embodiment of this ozonolysis method is to ozonate 4,4-dichloro-5,5,5-trifluoro-2-pentenecarboxylic acid methyl ester in acetic acid at 20°C, and then add zinc powder to the reaction mixture. Add the suspension aqueous solution and extract 2.2- from the mixture.
Dichloro-3,3,3-trifluoropropionaldehyde is directly distilled.

Chlorpyridines of the formula can be used for the preparation of various active substances in known manner via one or several intermediate steps.
Used in particular in the production of insecticides and herbicides (e.g. Swiss Patent No. 622170, European Patent Publication No. 00176, European Patent Publication No. 00483 and Swiss Patent No. 04414)
European Patent Application No. 818101818; German Publication No. 2812649 and German Publication No. 2748636; South African Patent No. 7802440; Japanese Patent Publication No. 54-
115380, 55-038356, 55-079369 and 56-39069 and Belgian Patent Specification No. 862325).

[Embodiments of the invention]

The present invention will be explained in more detail with reference to the following examples.

Example 1 (a) Production of 4-formyl-2-methyl-2,4,4-trichlorobutyronitrile 14.7 g of trichloroacetaldehyde, 13.5 g of methacrylonitrile and copper powder (Org.Synth.
Coll. Vol., 339), 0.3 g of the bronze was heated with 30 ml of acetonitrile in an enamel autoclave for 15 hours. After cooling, the refrigerant was distilled off at about 40-50° C. while reducing the pressure using a water jet pump.
50 ml of diethyl ether was added to the residue and the precipitated copper sludge was filtered off. After distilling off the diethyl ether, the residue was rectified under high vacuum.
A fraction boiling at 76-78 °C at 13 pa was collected. 4
13.8 g of -formyl-2-methyl-2,4,4-trichlorobutyronitrile was obtained as a colorless oil.

IR-spectrum (liquid film): 2250 (CN), 1750
(CO) cm ^-1 .

^1H -NMR-spectrum (60MHz, CDCl ₃
middle): 9.30 (s, 1H, -CHO); 3.22 (s, 2H, C
_-3H2 ); 2.60 (s, 3H, _-CH3 ) ppm.

Elemental analysis as C ₆ H ₆ Cl ₃ NO (molecular weight 214.48): Calculated values C 33.60% H 2.82%
N 6.53% Cl 49.59% Actual value C 34.1% H 3.1%
N 6.8% Cl 48.6% (b) Production of 2,5-dichloro-3-methylpyridine 4-formyl-2 obtained in Example 1(a)
21.4 g of -methyl-2,4,4-trichlorobutyronitrile were heated to 145 DEG C. for 4-5 hours while introducing a weak stream of dry HCl gas. After cooling, the blackish melt was steam distilled. 2.5-
9.9 g of dichloro-3-methylpyridine was obtained as colorless crystals.

Melting point: 42°C (recrystallized from CH ₃ OH/H ₂ O volume ratio 4:1).

^1H -NMR-spectrum (60MHz, CDCl ₃
middle): 8.15 (d, 1H, H of C-6); 7.50 (d, 1H,
H of C-4); 2.40 (s, 3H, _-CH3 ); ppm.

Elemental analysis as C ₆ H ₅ Cl ₂ N (molecular weight 162.02): Calculated values C 44.48% H 3.11%
N 8.65% Cl 43.77% Actual value C 44.4% H 2.9%
N 7.9% Cl 53.8%.

Example 2 (a) Production of 4-formyl-2,4-dichlorovaleronitrile 2,2-dichloropropionaldehyde 12.7
g, 31.8 g of acrylonitrile, 0.3 g of copper powder and 30 ml of acetonitrile were heated to 120° C. for 12 hours in an enamel autoclave. The solvent and excess acrylonitrile were distilled off under water pump vacuum and the residue was dissolved in 50 ml of diethyl ether. The ether solution was filtered, concentrated and the residue was rectified under high vacuum. 4-formyl-2・4-
11.7 g of dichlorvaleronitrile was obtained as an oil.

Boiling point: 70-74℃/13pa IR-spectrum (liquid film): 2250 (CN), 1750
(CO) cm ^-1 .

^1H -NMR-spectrum (100MHz, CDCl ₃
middle): 9.5 (s, 1H, -CHO); 4.75 (t, 1H, C-
2H); 2.3-3.1 (m, 2H, C-3H)
1.78 (s, 3H, _-CH3 ) ppm.

According to the ¹ H-NMR spectrum, two isomers were present in a ratio of approximately 1:1.

Elemental analysis as C ₆ H ₇ Cl ₂ NO (molecular weight 180.03): Calculated values C 40.03% H 3.92%
N 7.78% Cl 39.39% Actual value C 41.0% H 4.0%
N 7.9% Cl 38.5%.

(b) Production of 2,3-dichloro-5-merylpyridine 4-formyl-2,4 obtained in Example 2(a)
-18.0g of dichlorvaleronitrile and 0.1g of copper powder
After pressurizing 10.0 g of dry HCl gas into a tantalum autoclave, the mixture was heated to 150° C. for 5 hours.
After cooling, the contents of the autoclave were steam distilled. 2,3-dichloro-5-methylpyridine
10.5 g was obtained as colorless crystals.

Melting point: 46-47℃.

^1H -NMR-spectrum (100MHz, CDCl ₃
middle): 81.3 (d, 1H, H of C-6); 7.59 (d, 1H,
C-4 H); 2.34 (s, 3H, -CH3).

Elemental analysis as C ₆ H ₅ Cl ₂ N (molecular weight 162.02): Calculated values C 44.48% H 3.11%
N 8.65% Cl 43.77% Actual value C 44.4% H 3.2%
N 8.6% Cl 43.5% Example 3 (a) Production of 4-formyl-2-methyl-2,4-dichlorovaleronitrile 2,2-dichloropropionaldehyde 12.7
g, 13.5 g of methacrylonitrile, 0.5 g of copper () chloride and 40 ml of acetonitrile in a Tartan autoclave at 130°C for 1 hour, then
Heat at 150℃ for 2 hours. After distilling off the solvent and steam distilling excess methacrylonitrile, the residue was dissolved in 50 ml of diethyl ether and filtered. The diethyl ether was distilled off under reduced pressure and the residue was rectified under high vacuum. A fraction boiling at 76-77 °C at 13 pa was collected. 4-formyl-2-methyl-2,4-dichlorovaleronitrile 10.8g
was obtained as an ocher oil.

IR-spectrum (liquid film): 2250, 1750 (CO) cm
^-1 .

^1H -NMR-spectrum (60MHz, CDCl ₃
(middle): (1:1 diastereomeric mixture) 9.71 and 9.53, respectively (s, 1H, -CHO);
2.96 (s, 4H, 2X−CH ₂ ); 2.14 (s, 6H,
2X−CH ₃ ); 2.02 (s, 3H, −CH ₃ ); 1.93
(s, 3H, _-CH3 )ppm.

Elemental analysis as C ₇ H ₉ Cl ₂ NO (molecular weight 194.06): Calculated values C 43.22% H 4.67%
N 7.21% Cl 36.53% Actual value C 43.6% H 4.6%
N 7.3% Cl 35.9%.

(b) Production of 2-chloro-3,5-dimethylpyridine 19.4 g of 4-formyl-2-methyl-2,4-dichlorovaleronitrile obtained in Example 3(a)
160-170 while introducing a weak dry HCl gas flow.
℃ for 4 hours. After cooling, the blackish melt was steam distilled. The effluent was extracted by shaking with diethyl ether, dried and concentrated under reduced pressure.
The remaining ocher oil was distilled. Boiling point of 7.36g of 2-chloro-3,5-dimethylpyridine
Obtained as an ocher oil at 110°C/2500pa.

^1H -NMR-spectrum (60MHz, CDCl ₃
middle): 8.0 (d, 1H, H of C-6); 7.31 (d, 1H,
C-4 H, J6-4 = 2.0Hz); 2.34 (s, 3H,
-CH ₃ ); 2·28 (s, 3H, -CH ₃ ) ppm.

Elemental analysis as C ₇ H ₈ ClN (molecular weight 141.60): Calculated values C 59.38% H 5.65%
N 9.83% Cl 25.04% Actual value C 59.1% H 5.9%
N 9.7% Cl 25.3%.

According to ¹ H-NMR data, this compound is J.
It corresponded to 2-chloro-3,5-dimethylpyridine described in Chem. Soc. PerKin I ( 1979 ), 1578.

Example 4 (a) Production of 2,2-dichloro-3,3,3-trifluoropropionaldehyde 4,4-dichloro-5,5,5-trifluoro-2-methyl-pentenecarboxylic acid methyl ester (100.4 g ) in a solution of glacial acetic acid (800ml)
19.2 g of ozone (mixture with oxygen) was introduced at 20°C. Next, a suspension of zinc powder (15 g) in water (15 ml) was added and distilled, and the produced 2,2-dichloro-3,3,3-trifluoropropionaldehyde was distilled under normal pressure. 52.8 g of product was obtained as a colorless pungent liquid.

Boiling point: 66-67°C IR (CCl ₄ ): ν(CO) 1770 cm ^-1 .

^1H -NMR-spectrum ( _CDCl3 ): δ=9.3
(q, J=2Hz) ppm.

Elemental analysis as C ₃ HCl ₂ F ₃ O (molecular weight 180.9): Calculated values C 19.92% H 0.56%
N 31.50% Cl 39.19% Actual value C 20.2% H 0.8%
N 30.9% Cl 38.5%.

(b) 4-formyl-2,4-dichloro-5,5.
Production of 5-trifluorovaleronitrile 36 g of 2,2-dichloro-3,3,3-trifluoropropionaldehyde, acetonitrile
80 ml of acrylonitrile and 0.5 g of copper() chloride were heated in a tantalum autoclave for 12 hours. Work-up according to Example 1(a) gives 4-formyl-2,4-dichloro-
5,5,5-trifluorovaleronitrile was obtained as a colorless oil.

Boiling point: 85-86℃/900pa.

IR (CCl ₄ ): ν(CN) 550cm ^-1 , ν(CO) 1750cm
^{-1 1} H-NMR-spectrum (CDCl ₃ ): δ=9.56
(m, 1H, CHO); 4.7 (m, 1H, C-2-
3); 2.7-3.3 (m, 2H, C-3H) ppm (diastereomer mixture).

Elemental analysis as C ₆ H ₄ Cl ₂ F ₃ NO (molecular weight 234.0): Calculated values C 30.80% H 1.73%
N 5.99% Cl 24.36% Actual value C 31.5% H 2.0%
N 5.9% Cl 23.8%.

(c) Production of 2,3-dichloro-5-trifluoromethylpyridine 4-formyl-2,4- obtained from Example 4(b)
25.0 g of dichloro-5.5.5-trifluorovaleronitrile was heated at 170° C. for 5 hours with 0.1 g of copper powder in a tantalum autoclave. Steam distillation yielded 11.9 g of 2,3-dichloro-5-trifluoromethylpyridine as a colorless oil with a peppery odor.

Boiling point: 80℃/3325pa.

^1H -NMR-spectrum ( _CDCl3 ): δ=8.63
(d, J=2Hz, 1H); 8.03 (d, J=2Hz,
1H) ppm.

Elemental analysis as C ₆ H ₂ Cl ₂ F ₃ N (molecular weight 216.0): Calculated values C 33.36% H 0.93%
N 6.48% Cl 32.82% F 26.28% Actual value C 33.5% H 1.0%
N 6.5% Cl 33.4% F 25.9%

Claims (1)

[Claims] 1. The following formula (In the formula, R is chlorine and R ¹ is a methyl or trifluoromethyl group, or R is a methyl, trichloromethyl or trifluoromethyl group and R ¹
represents hydrogen, or R and R ¹ represent a methyl group. ). 2. A compound of the formula according to claim 1, wherein R is chlorine and R ¹ is a methyl group, or R is trifluoromethyl, trichloromethyl or a methyl group and R ¹ is hydrogen. 3 4-formyl-2,4-dichloro-5,5.
The compound according to claim 1, which is 5-trifluorovaleronitrile. 4 In the presence of a catalyst, (a) trichloroacetaldehyde to methacrylonitrile or α-trifluoromethyl-acrylonitrile, (b) 2,2-dichloropropionaldehyde, pentachloropropionaldehyde or 2.
The following formula is characterized in that 2-dichloro-3,3,3-trifluoro-propionaldehyde is added to acrylonitrile, or (c) 2,2-dichloropropionaldehyde is added to methacrylonitrile. (In the formula, R is chlorine and R ¹ is a methyl or trifluoromethyl group, or R is a methyl, trichloromethyl or trifluoromethyl group and R ¹
represents hydrogen, or R and R ¹ represent a methyl group. ) A method for producing the compound shown in 5. The method according to claim 4, wherein the addition reaction is carried out at a temperature of 70 to 160°C. 6 The addition reaction is carried out in a closed system at a temperature of 70 to 160 °C,
The method according to claim 4, wherein the reaction is carried out under a pressure corresponding to the reaction temperature. 7. The method according to claim 4, wherein copper powder, bronze, copper(), chloride or bromide of copper(), or iodide of copper(), or a mixture thereof is used as a catalyst. 8 0.01 to 10 mol of catalyst to aldehydes
%, more preferably from 0.1 to 5 mol %. 9. The method according to claim 4, wherein the addition reaction is carried out in the presence of an inert organic solvent. 10 The addition reaction is carried out in an alkanecarboxylic acid nitrile having 2 to 5 carbon atoms as a solvent, in 3-alkoxypropionitrile having an alkoxy group having 1 to 2 carbon atoms, or in an excess of acrylonitrile, methacrylonitrile or methacrylonitrile. 5. The method according to claim 4, which is carried out in α-trifluoromethacrylonitrile.