JPH0417934B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel 2-(2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one and a process for its preparation.

The object of the invention is to obtain the formula Ia 2-(2',2',2'-tribromoethyl)-4- represented by [In the formula, R ₁ and R ₂ represent a methyl group]
An object of the present invention is to provide chlorocyclobutan-1-one and a method for producing the same.

2-(2′,2′,2′-tribromoethyl)-4-chlorocyclobutan-1-one of formula (Ia) is a useful intermediate and is suitable for bases such as alkali metal hydroxides and alkali metal alcoholates. 2- by a known method (Favorski reaction) by heating with
(2',2'-dibromovinyl)-cyclopropane-1
-carboxylic acids or esters thereof, which can be further converted into suitable alcohols, such as m-
Reaction with phenoxy-α-cyanobenzyl alcohol yields an ester with insecticidal activity. However, 2-(2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one of formula Ia is
It is obtained in significantly better yield than 2-(2',2',2'-tribromoethyl)-4-bromocyclobutan-1-one of the corresponding formula. Therefore, 2−(2′,
2'-dibromovinyl)-cyclopropane-1-carboxylic acid and its insecticidal active esters
-(2',2',2'-tribromoethyl)-4-bromocyclobutan-1-one of formula Ia2-(2',2',2'-tribromoethyl )-4-chlorocyclobutan-1-one in better yields. 2-(2',2'-dibromovinyl)-cyclopropane-1-carboxylic acid esters having insecticidal action are described, for example, in DE-A-232-6077 and DE-A-2439177.

2-(2′,2′,2′-tribromoethyl)- of formula Ia
According to the invention, 4-chlorocyclobutan-1-one has the following formula; of 2-chloro-4,4,4-tribromobutyric acid chloride in the presence of an organic base according to the following formula; [In the formula, R ₁ and R ₂ represent the above-mentioned meanings] by reacting with an olefin represented by the following formula; 2-(2',2',2'-tribromoethyl)-2 represented by [in the formula, R ₁ and R ₂ have the above-mentioned meanings]
-chlorocyclobutan-1-one, which is then converted to 2-(2', 2',
It is produced by rearrangement to 2'-tribromoethyl)-4-chlorocyclobutan-1-one.

2-chloro-4,4,4-tribromobutyric acid chloride of the formula is a new compound. It can be produced by first reacting 4,4,4-tribromobutyric acid with an inorganic acid chloride to convert it into 4,4,4-tribromobutyric acid chloride, and then chlorinating the α-position.

The 4,4,4-tribromobutyric acid required as a starting material is obtained by reacting bromoform with acrylonitrile and then hydrolyzing the 4,4,4-tribromobutyric acid nitrile formed (J. Amer. Chem.Soc.67, pp.601-602, 1945).

As inorganic acid chlorides, phosphorus trichloride, phosphorus oxychloride, phosgene, thionyl chloride and oxalyl chloride can be used. The reaction of 4,4,4-tribromobutyric acid with the inorganic acid chloride is advantageously carried out in the presence of catalytic amounts of dimethylformamide. As a solvent, an excess of inorganic acid chloride can be used.

2- of 4,4,4-tribromobutyric acid chloride
Chlorination at the position is carried out by a conventional method. As a chlorinating agent,
For example, free chlorine or N-chlorosuccinimide can be used. A preferred chlorinating agent is N-chlorosuccinimide. The chlorination is carried out immediately after the reaction of the inorganic acid chloride with 4,4,4-tribromobutyric acid in an excess of the inorganic acid chloride as a solvent, without isolating the 4,4,4-tribromobutyric acid chloride. be able to. However, 4,4,4-tribromobutyric acid chloride was isolated and
If the subsequent chlorination is carried out separately, a purer product is obtained. Chlorination is carried out at temperatures between 40 and 90℃, especially
Carry out at a temperature of 60-70 ° C. During the chlorination it is advantageous to irradiate the reaction mixture with UV radiation or to add some known free-radical initiators, such as dibenzoyl peroxide or azobisisobutyronitrile.

The reaction of 2-chloro-4,4,4 tribromobutyric acid chloride of the formula with an olefin of the formula is advantageously carried out in the presence of a solvent. Such solvents include, for example, optionally halogenated aromatic or aliphatic hydrocarbons such as benzene, toluene, xylene, chlorobenzene, dichloro- and trichlorobenzene, n-pentane, n-hexane, n-octane. , methylene chloride, chloroform, carbon tetrachloride, 1,1,2,2-tetrachloroethane and trichloroethylene are suitable. Other suitable solvents are cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane, cycloaliphatic ketones such as cyclopentanone and cyclohexanone, and aliphatic ketones, aliphatic and cyclic ethers, alkyl nitriles, alkoxy moieties having 1 or 2 carbon atoms. 3-alkoxypropionitriles, especially acetonitrile and 3-methoxypropionitrile.

Particularly suitable solvents are aliphatic, cycloaliphatic and aromatic hydrocarbons, especially C5-C8 alkanes,
benzene, toluene and especially n-hexane and cyclohexane.

As a solvent it is also possible to use an excess of the olefin of the formula.

Suitable organic bases to be present when carrying out the reaction of 2-chloro-4,4,4-tribromobutyric acid chloride of the formula with olefins of the formula are, for example, tertiary amines, in particular those in which the alkyl group has 1 carbon atom in each case.
to 4 trialkylamines, cyclic amines such as pyridine, quinoline, N-alkylpyrrolidine, N-alkylpiperidine, N,N-dialkylpiperazine and N-alkylmorpholine or dialkylaniline in which the alkyl group has 1 or 2 carbon atoms, respectively. , such as N-methylpyrrolidine, N-ethylpiperidine, N,N'-dimethylpiperazine, N-ethylmorpholine and N,N-
Dimethylaniline, as well as bicyclic amidines such as 1,5-diazabicyclo[5.4.0]undec-5
-ene and 1,5-diazabicyclo[4.3.0]non-5-ene and bicyclic diamines such as 1,4-
It is diazabicyclo[2.2.2]octane.

The reaction of the 2-chloro-4,4,4-tribromobutyric acid chloride of the formula with the olefin of the formula is carried out, inter alia, in the presence of a trialkylamine whose alkyl group has in each case 1 to 4 carbon atoms. Particularly preferred bases are triethylamine and pyridine.

The organic base is used in at least an equimolar amount or in slight excess relative to 2-chloro-4,4,4-tribromobutyric acid chloride of the formula.

Olefin of the formula also includes 2-chloro-
It is used in at least an equimolar amount to 4,4,4-tribromobutyric acid chloride. However, it is generally advantageous to use an excess of olefin, in which case the olefin can also serve as a solvent, as mentioned above. If readily volatile olefins are used, the reaction can also be carried out under pressure.

In particular, olefins of the formula R ₁ and R ₂ represent a methyl group and the other a hydrogen atom or a methyl group, or R ₁ and R ₂ taken together have 2 or 3 carbon atoms. Mention may be made of those representing alkylene groups, namely isobutylene, propene, methylenecyclopropane and methylenecyclobutane. Particularly preferred are isobutylene and methylenecyclopropane.

The reaction temperature can vary within a wide range. Generally the temperature is 0 to 200°C, preferably 20 to 160°C.

2-(2',2',2'-tribromoethyl)- of the formula
2-Chlorocyclobutan-1-one is also a new compound. The formula 2-(2′,
2′,2′-tribromoethyl)-2-chlorocyclobutan-1-one is then converted to 2-(2′,2′,2′-
tribromoethyl)-4-chlorocyclobutane-
As a catalyst for rearrangement to 1-one, an inorganic protonic acid or a quaternary ammonium halide can be used.

2-(2',2',2'-tribromoethyl)- of the formula
2- of formula Ia of 2-chlorocyclobutan-1-one
The rearrangement according to the invention to (2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one was unexpected and for cyclobutanone monohalogenated in the α-position. was unknown. This rearrangement proceeds in high and often quantitative yields.

2-(2',2',2'-tribromoethyl)- of the formula
2- of formula Ia of 2-chlorocyclobutan-1-one
Inorganic protic acids can be used as acid catalysts for the rearrangement to (2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one. Suitable inorganic protic acids are, for example, hydrohalic acids such as hydrogen chloride, hydrogen bromide, hydrogen fluoride and hydrogen iodide, nitric acid, phosphoric acid and sulfuric acid. Particularly preferred inorganic protic acids are hydrohalic acids.

If acids or bases are used in excess, they may also serve as solvents.

Furthermore, it is also possible to use protic acids, especially hydrohalic acids and quaternary ammonium halides.

The following formula: (In the formula, M represents a fluorine, bromine, iodine or especially a chlorine atom, Q ₄ represents an alkyl group having 1 to 18 carbon atoms, a cyclohexyl group, a benzyl group, a phenyl group or a naphthyl group, Q ₅ , Q ₆ and Q ₇ independently has 1 carbon atom
represents an alkyl group of 1 to 18. ) and N-alkyl-pyridinium halides having an alkyl group of 1 to 18 carbon atoms,
Particular preference is given to the corresponding chlorides. Examples of these salts are: tetramethyl-, tetraethyl-, tetra-n-propyl-, tetra-n-butyl-ammonium-chloride, -bromide and iodide, trimethyl-hexadecyl ammonium chloride, benzyldimethylhexadecyl. Ammonium chloride, benzyldimethyltetradecylammonium chloride, benzyl-trimethyl-, -triethyl- and -tri-
n-Butyl-ammonium chloride, n-butyl-tri-n-propylammonium bromide, octadecyltrimethylammonium bromide, phenyltrimethylammonium bromide or -chloride, hexadecylpyridinium-bromide and -chloride.

Other cocatalysts that may be used are alkali metal halides such as potassium iodide, sodium iodide, lithium iodide, potassium bromide, sodium bromide, lithium bromide, potassium chloride, sodium chloride, lithium chloride, potassium fluoride, fluoride, etc. sodium fluoride and lithium fluoride.

These cocatalysts catalyze the reaction even in the absence of the ammonium salt, in which case open-chain or macrocyclic polyethers (crown ethers)
It is advantageous to speed up the reaction by adding . Examples of such crown ethers are 15-crown-5,
18-crown-6, dibenzo-18-crown-
6, dicyclohexyl-18-crown-6 and 5,6,14,15-dibenzo-7,13-diaza-
1,4-dioxa-cyclobentabeca-5,14-
It's Jien.

The amount of catalyst used can vary within wide limits.
In some cases, the presence of trace amounts of catalyst is sufficient. However, it is generally preferred to use from about 0.1 to 15% by weight of catalyst based on the compound of formula.

The rearrangement may be carried out in the melt or in an inert organic solvent. The rearrangement reaction temperature in the molten state is generally about 60 to 150°C, especially about 80 to 130°C.

Suitable catalysts for the rearrangement in the melt are tetraalkylammonium halides, especially tetraalkylammonium chlorides, bromides and iodides, each alkyl group having from 1 to 18 carbon atoms.

Examples of suitable inert organic solvents are optionally nitrated or halogenated aliphatic, cycloaliphatic or aromatic hydrocarbons such as n-hexane, n-pentane, cyclohexane, benzene, toluene. , xylene, nitrobenzene, chloroform, carbon tetrachloride, trichloroethylene,
1,1,2,2-tetrachloroethane, nitromethane, chlorobenzene, dichlorobenzene and trichlorobenzene; lower aliphatic alcohols, such as those having less than 6 carbon atoms, such as methanol, ethanol, propanol, isopropanol, butanol and pentanol: aliphatic Diols such as ethylene glycol and diethylene glycol; number of carbon atoms in the alkyl moiety is 1 to 4, respectively
ethylene glycol monoalkyl ethers and diethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether and diethylene glycol monoethyl ether; cyclic amides such as N-methyl-2-pyrrolidone, N-acetyl-2
- pyrrolidone and N-methyl-ε-caprolactam: carboxylic acid amides such as tetramethylurea and dimorpholinocarbonyl; amides of phosphorous acid, amides of phosphoric acid, amides of phenylphosphonic acid or aliphatic phosphones having 1 to 3 carbon atoms in the acid moiety; Amides of acids e.g. phosphoric acid triamide, phosphoric acid tris-
(dimethylamide), phosphoric acid trimorpholide, phosphoric acid tripyrrolidide, phosphoric acid bis-(dimethylamide)-morpholide, phosphoric acid-dimethylamide-diethylamide-morpholide, tris-(dimethylamide) phosphorous acid and tetramethyldiamide of methanephosphonic acid; amide of sulfuric acid and amides of aliphatic or aromatic sulfonic acids such as tetramethylsulfamide,
Dimethylamide or p-toluenesulfonic acid amide of methanesulfonic acid; sulfur-containing solvents such as organic sulfones and sulfoxides such as dimethylsulfoxide and sulfolane; aliphatic and aromatic nitriles, 3-alkoxypropionitriles, aliphatic ketones, aliphatic Alkyl and alkoxyalkyl esters of monocarboxylic acids, cyclic ethers, dialkyl ethers, N,N of aliphatic monocarboxylic acids
-disubstituted amides and ethylene glycol dialkyl ethers and diethylene glycol dialkyl ethers of the type mentioned in the first step.

For the rearrangement in the presence of acid catalysts, polar solvents, especially lower alcohols such as methanol, ethanol and butanol, N,N-dialkylamides of C1 -C3 aliphatic monocarboxylic acids in the acid part, especially N,N-dimethyl Preference is given to using formamide or dialkyl sulfoxides such as dimethyl sulfoxide.

Aprotic and strongly polar solvents, such as N,N-disubstituted amides of the aliphatic monocarboxylic acids, cyclic amides, amides of carbonic acid, amides of phosphorous acid, amides of phosphoric acid, amides of phenylphosphonic acid, or amides of aliphatic phosphonic acids. In amides, amides of sulfuric acids, amides of aliphatic or aromatic sulfonic acids, and dialkyl sulfoxides such as dimethyl sulfoxide, the reaction proceeds without the addition of base or acid. In this case, the solvent acts as a catalyst.

However, in general, when the rearrangement is carried out in the presence of an inert organic solvent, hydrohalic acids, especially HCl and HBr, and tetraalkylammonium
Halides, especially those containing 1 or more carbon atoms in each alkyl group
18 tetraalkylammonium chloride
Add bromide and iodide.

Particularly preferred solvents are C1 -C4 aliphatic alcohols, toluene, xylene, chlorobenzene, dioxane, acetonitrile, 3-methoxypropionitrile, ethylene glycol diethyl ether and di-isopropyl ketone.

The rearrangement reaction temperature in the presence of an inert organic solvent is generally about 0 to 150°C, preferably 80 to 150°C.
The temperature is 130℃.

By the method of the present invention, 2-
Novel 2-(2′,2′,2′-tribromoethyl)- of formula Ia substituted in the 3-position, suitable as an intermediate for the synthesis of (2′,2′-dibromovinyl)-cyclopropanecarboxylic acid derivatives. 4-Chlorocyclobutan-1-one is obtained simply and in good yields using readily available starting materials.

The method of the invention comprises 2-chloro-4,4,
4-Tribromobutyric acid chloride or the chloroketene produced by the elimination of hydrogen chloride from it is reacted with an olefin of the formula to form 2-tribromobutyric acid chloride substituted at the 3-position.
2- of the formula is not suitable for conversion into (2',2'-dibromovinyl)-cyclopropanecarboxylic acid derivatives.
(2',2',2'-tribromoethyl)-2-chlorocyclobutan-1-one is first produced, and then this is converted into a monohalogenated cyclobutanone, which is not conventionally seen in the case of cyclobutanone monohalogenated at the α-position. The 2-(2',2',2'-tribromoethyl)-4-chlorocyclobutane-1-
This is a very unexpected and completely unforeseen method.

The new 2-(2′,2′,2′-tribromoethyl)-4-chlorocyclobutane-1 of formula Ia as starting material
The 3-substituted 2-(2',2'-dibromovinyl)-cyclopropanecarboxylic acid and its insecticidal active ester, which can be prepared using -one, can be prepared using the following formula: [In the formula, R ₁ and R ₂ represent the meanings described in the formula,
R is a hydrogen atom, a C1-C4 alkyl group, or the following formula: (In the formula, R ₃ represents an oxygen atom, a sulfur atom, or a vinylene group, R ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a benzyl group, a phenoxy group, or a phenylmercapto group, and R ₅ represents hydrogen represents an atom or an alkyl group having 1 to 4 carbon atoms, R ₆ represents a hydrogen atom, a cyano group or an ethynyl group, or one of R ₁ and R ₂ represents a methyl group and the other represents a hydrogen atom or a methyl group. (wherein R ₃ represents a vinylene group, R ₄ represents a phenoxy group, and R ₅ represents a hydrogen atom, it also represents an alkyl group having 1 to 5 carbon atoms.) represents. ] It can be expressed as

The 2-(2',2'-dibromovinyl)-cyclopropanecarboxylic acid derivatives of the formula in which R is a radical of the formula are suitable for controlling pests, especially insects, on various animals and plants. The nature, fields of application and applicable dosage forms of these active compounds are described, for example, in Nature 246, pages 169-170 (1973);
Nature 248 pp. 710-711 (1974); Proceedings 7th British Insecticide and Fungicide Conference, 721-
728 pages (1973); Proceedings 8th British
Insecticide and Fungicide Conference, 373−
378 pages (1975); J.Agr.Food Chem. 23 115 pages (1973); US Patent No. 3961070:
German patent publications no. 2553991, 2439177,
Publications No. 2326077 and No. 2614648.

2-(2′,2′,2′-tribromoethyl)- of formula Ia
2- of the formula 4-chlorocyclobutan-1-one
The conversion into the (2',2'-dibromovinyl)-cyclopropanecarboxylic acid derivative is carried out in a manner known per se by heating in the presence of a suitable base. Examples of suitable bases are alkali metal hydroxides and alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, calcium hydroxide and barium hydroxide. Alkali metal carbonates and bicarbonates and alkaline earth metal carbonates and bicarbonates such as calcium carbonate, barium carbonate, potassium carbonate, sodium carbonate, sodium bicarbonate and potassium bicarbonate can also be used as bases. Other suitable bases are alcoholates derived from the group R as defined above, in particular the corresponding sodium and potassium alcoholates. The use of such alcoholates has the advantage that the corresponding esters are obtained directly.
On the other hand, when alkali metal hydroxides and alkaline earth metal hydroxides are used, salts of 2-(2',2'-dibromovinyl)-cyclopropanecarboxylic acid formed with these bases are first formed. . However, these salts can also be converted into esters in simple ways known per se, for example by converting them into the corresponding acid chlorides and reacting with alcohols derived from the radical R.

Depending on the nature of the base used, 2-(2',
The conversion of 2',2'-tribromoethyl)-4-chlorocyclobutan-1-one into a 2-(2',2'-dibromovinyl)-cyclopropanecarboxylic acid derivative of the formula It is advantageously carried out in or in an organic medium. If the base used is an alkali metal carbonate or an alkaline earth metal carbonate, the reaction is carried out in an aqueous or aqueous-organic medium. The reaction in the presence of alkali metal hydroxides or alkaline earth metal hydroxides and alkali metal carbonates is also advantageously carried out in aqueous or aqueous-organic media. In this case, acidification of the reaction mixture, for example by addition of concentrated hydrochloric acid, results in the free form of the formula (R=
H) 2-(2',2'-dibromovinyl)-cyclopropanecarboxylic acid is obtained.

2 of formula Ia in aqueous-organic medium or organic medium
-(2′,2′,2′-tribromoethyl)-4-chloro-cyclobutan-1-one with the formula 2-(2′,
Suitable solvents for the conversion to the 2'-dibromovinyl)-cyclopropanecarboxylic acid derivatives are lower alcohols such as those having 1 to 6 carbon atoms, benzyl alcohol, aliphatic or cyclic ethers such as diethyl ether, di-n -propyl ether, di-isopropyl ether, tetrahydrofuran and dioxane, and aliphatic, cycloaliphatic or aromatic hydrocarbons such as n-pentane, n-hexane, cyclohexane, benzene, toluene and xylene.

2-(2′,2′,2′-tribromoethyl)- of formula Ia
2- of the formula 4-chlorocyclobutan-1-one
The conversion to the (2',2'-dibromovinyl)-cyclopropanecarboxylic acid derivative is generally carried out at the boiling point of the chosen reaction medium. Reaction temperatures of 40 to 120°C are particularly preferred.

2-(2′,2′,2′-tribromoethyl)- of formula Ia
4-chlorocyclobutan-1-one has the formula 2-
When converted to (2′,2′-dibromovinyl)-cyclopropanecarboxylic acid derivative, the following formula: The corresponding 2-(2',2',2'-tribromoethyl)-cyclopropanecarboxylic acid derivative represented by (wherein R, _R1 and _R2 have the above-mentioned meanings) is
Produced as an intermediate. This product can be isolated if the reaction temperature is kept below 40°C and/or if less than an equivalent amount of base is used. Above 40°C, these intermediates can be converted to 2-(2',2'-dibromovinyl)- of the corresponding formula with elimination of HBr by further addition of base.
Converted to cyclopropanecarboxylic acid derivatives.

2-(2',2',2'-tribromoethyl)- of the formula
Cyclopropanecarboxylic acid derivatives of formula Ia are 2-
(2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one is prepared from (2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one in the presence of a hydroxyl-containing reagent which can at the same time serve as a solvent. For example, acetone
It can also be photochemically synthesized by adding cyclohexanone, benzophenone, acetophenone, higher alkylaryl ketones, thioxanthone, etc.) and irradiating the mixture with ultraviolet rays. Examples of hydroxyl-containing reagents are alkanols such as methanol, ethanol, etc., and especially water.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 (a) Preparation of 4,4,4-tribromobutyric acid chloride 324.8 g (1.0 mol) of 4,4,4-tribromobutyric acid was heated with 600 g of thionyl chloride and 1 ml of dimethylformamide first at 40° C. for 2 hours and then at 3 Warm to 75°C for an hour.

The excess thionyl chloride is then distilled off and the residue is purified under high vacuum. Boiling point 71-73℃/0.05mm
Hg 4,4,4-tribromobutyric acid chloride
Obtain 326.0 g (95% of theory).

(b) Production of 2-chloro-4,4,4-tribromobutyric acid chloride 4,4,4-tribromobutyric acid chloride
Dissolve 343.2 g (1.0 mol) in 600 g of thionyl chloride, and simultaneously expose to 60 g of thionyl chloride using a mercury high-pressure lamp.
266.0 g (2.0 mol) of N-chlorsuccinimide is added little by little at <RTIgt;C. After finishing the addition of N-chlorsuccinimide, the resulting mixture was heated to 60°C.
Stir and expose to light for 5 hours. The thionyl chloride is distilled off and the residue is purified under high vacuum. Boiling point 59~
309.7 g of 2-chloro-4,4,4-tribromobutyric acid chloride (81% of theory) at 63°C/0.05 mmHg
get.

(c) 2-(2',2',2'-tribromoethyl)-2-
Chloro-3,3-dimethylcyclobutane-1-
Production of on In an autoclave, 360 ml of cyclohexane
90.6 g (0.24 mol) of 2-chloro-4,4,4-tribromobutyric acid chloride was charged therein, and 134 g (2.4 mol) of isobutylene was press-injected. Then 65
A solution of 24.2 g (0.24 mol) of triethylamine in 120 m of cyclohexane is pumped in for 4 hours at °C. After the addition of the triethylamine solution is complete, the reaction mixture is kept at 65° C. for a further 3 hours.
The triethylamine hydrochloride formed is filtered off, and the solvent is distilled off. The residue is dissolved in a solvent mixture consisting of equal parts of toluene and hexane and filtered through silica gel. After evaporation of the solvent, 51.4 g (theoretical amount) of 2-(2',2',2'-tribromoethyl)-2-chloro-3,3-dimethylcyclobutan-1-one with a melting point of 95-97°C was obtained from the filtrate. 54%).

Infrared absorption spectrum (CCl ₄ ), (cm ^-1 );
1800 (CO). Proton nuclear magnetic resonance ( ¹ H−
NMR) spectrum (100MHz, CDCl ₃ )
(ppm): 1.39 and 1.41 (1s each: 3H each),
2.86-3.22 (m, 2H) 3.55-4.15 (m, 2H) (d) 2-(2',2',2'-tribromoethyl)-3,
3-dimethyl-4-chlorocyclobutane-1-
Preparation of 22.8 g of 2-(2',2',2'-tribromoethyl)-2-chloro-3,3-dimethylcyclobutan-1-one in 220 ml of absolute ethanol after saturation with hydrogen chloride. (0.054 mol) is dissolved.
The resulting solution is stirred at 80°C for 5 hours. The reaction mixture is then concentrated on a rotary evaporator to about 1/3 of its original volume, mixed with water and extracted with ether. The ethereal extract is washed first with saturated sodium chloride solution and then with sodium bicarbonate solution and dried over sodium sulfate. The residue obtained after distilling off the ether was subjected to chromatography on silica gel,
In this case, toluene is used as an eluent. After combining the pure fractions and evaporating, the melting point is 87 ~
2-(2',2',2'-tribromoethyl)- at 89℃
3,3-dimethyl-4-chlorocyclobutane-
17.1 g (75% of theory) of 1-one are obtained.

Infrared absorption spectrum (CCl ₄ ), (Cm ^-1 );
1805 (CO). Proton nuclear magnetic resonance ( ¹ H−
NMR) spectrum (100MHz), ( _CDCl3 )
(ppm): 1.14 and 1.67 (1s each; each
3H) 3.08-3.68 (m, 3H) 4.77 (d, 1H) (e) Production of 2-(2',2'-dibromovinyl)-3,3-dimethylcyclopropane-1-carboxylic acid 2-(2 ',2',2'-tribromoethyl)-3,
3-dimethyl-4-chlorocyclobutane-1-
Mix 800 mg (2 mmol) of 100 mg with 5.6 ml of 5% caustic soda at 0°C. The resulting mixture is stirred first for 18 hours at 0°C and then for 1 hour at 80°C. Subsequently, the reaction mixture is first washed with diethyl ether, then acidified with concentrated hydrochloric acid while cooling and extracted with diethyl ether. The extract is washed with water, dried over magnesium sulphate and evaporated. The resulting 2-(2',2'-dibromovinyl)-
0.59 g (100% of theory) of 3,3-dimethylcyclopropane-1-carboxylic acid consists of 80% by weight of the cis-isomer and 20% by weight of the trans-isomer.

Infrared absorption spectrum (CHCl ₃ ), (Cm ^-1 );
1695 (CO), proton nuclear magnetic resonance ( ¹ H−
NMR) spectrum (100MHz, CDCl ₃ )
(ppm), 1.25 and 1.35 and 1.30 and 1.31 (1s, respectively; CH ₃ − for trans- and cis-compounds)
Group 2), 1.62-2.30 (m, 2H), 6.15 and 6.70 (1d each, intensity ratio 1:4,
Total 1H), Example 2 2-(2',2',2'-tribromoethyl)-3,
3'-dimethyl-4-chlorocyclobutane-1-
2-(2',2',2'-tribromoethyl)-2-chloro-3,3'-dimethylcyclobutan-1-one
1.17g and 0.2g of tetrabutylammonium chloride
are mixed without diluting with solvent and the resulting mixture is heated to 105° C. for 3 hours. The resulting melt is dispersed in a mixture of diethyl ether and water. The organic layer is filtered through silica gel and the clear liquid is concentrated to give 0.9 g of a colorless oil that gradually crystallizes. Since its spectroscopic data (infrared absorption spectrum and proton nuclear magnetic resonance) are the same as those of Example 1d, the obtained product was 3,
Identified as 3'-dimethyl-4-chlorocyclobutan-1-one.

Claims (1)

[Claims] Primary formula Ia; 2-(2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one represented by [wherein R ₁ and R ₂ represent a methyl group]. Quadratic formula Ia; To produce _2- ( ₂ ',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one represented by the following formula: of 2-chloro-4,4,4-tribromobutyric acid chloride in the presence of an organic base according to the following formula: By reacting with an olefin represented by [in the formula, R ₁ and R ₂ represent the above-mentioned meanings], the following formula: 2-(2', 2', 2'-tribromoethyl)-2- represented by [In the formula, R ₁ and R ₂ represent the above-mentioned meanings]
2-(2',2',2'-tri-tripropylene), which is characterized in that chlorocyclobutan-1-one is converted into Bromoethyl)-4
-Production method of chlorocyclobutan-1-one. 3 2-(2′,2′,2′-tribromoethyl) of formula
-2-chlorocyclobutan-1-one of formula Ia 2
-(2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one rearrangement at 80 to 130℃
The manufacturing method according to claim 2, which is carried out at a temperature of . 4 2-(2',2',2'-tribromoethyl) of formula
-2-chlorocyclobutan-1-one of formula Ia 2
The process according to claim 2, wherein the rearrangement to -(2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one is carried out in the presence of an inert solvent. 5 2-(2',2',2'-tribromoethyl) of formula
-2-chlorocyclobutan-1-one of formula Ia 2
The rearrangement to -(2',2',2'-tribromoethyl)-4-chlorocyclobutan-1-one is carried out using a C1-C4 aliphatic alcohol, toluene, xylene, chlorobenzene as a solvent, The process according to claim 4, which is carried out in dioxane, acetonitrile, 3-methoxypropionitrile, ethylene glycol, diethyl ether or diisopropyl ketone.