CS212349B2 - Method of making the esters of the 3-/2-arylvinyl/-2,2- dimethyl-cyclopropan-1-carboxyl acids - Google Patents

Abstract

Process for the preparation of 3-(2-arylvinyl)-2,2-dimethyl- cyclopropane-1-carboxylates of the formula <IMAGE> in which Ar represents a carbocyclic or heterocyclic aromatic radical, R represents alkyl and also a radical customary in pyrethroids and R<1> represents hydrogen or halogen, by reaction of appropriate 1-aryl-4- methylpenta-1,3-dienes (II) with appropriate diazoacetates, novel starting compounds II themselves and a plurality of different processes for the preparation thereof, for example by reaction of a beta -arylacrolein of the formula <IMAGE> in which Ar and R<1> have the above meaning, with triphenyl- isopropylphosphorane or with isopropylmagnesium chloride and also a process for the preparation of the compound VII in which R<1> represents halogen by reaction of an aryl methyl ketone with dimethylformamide and phosphorus oxyhalide. The compounds of the formula I can be used as intermediates for the preparation of insecticides.

Description

The invention also relates to a novel process for the preparation of partially known 3- (2-arylvinyl) -2,2-dimethylcyclopropane-1-carboxylic acid esters, to novel intermediates required therefor and to a process for the preparation of these intermediates.

It is already known that certain 3- (2-chloro-2-arylvinyl) -2,2-dimethylcyclopropane-1-carboxylic acid esters such as 3- (2-chloro-2-phenylvinyl) -2,2-dimethylcyclopropane- 1-carboxylic acids are obtained by treating the corresponding arylmethanesulfinate esters with a strong base, for example butyllithium, and then sequentially with carbon tetrachloride and a 3-formyl-2,2-dimethylmethyl-cyclopropane-1-carboxylic acid ester (see DOS no. 2,738,150).

However, this process for preparing 3- (2-chloro-2-arylvinyl) -2,2-dimethylcyclopropane-1-carboxylic acid esters has a number of disadvantages.

Strong bases, such as butyl lithium, required to deprotonate arylmethanesulfonic acid esters are sensitive to moisture and air, and therefore the usual procedure in which they are used should be conducted under an inert gas atmosphere such as nitrogen or argon and using inert, carefully dried solvents or diluents. Since the reaction is carried out at a very low temperature, about -70 ° C, the reaction mixture must also be vigorously cooled. Working up the reaction mixture to isolate the desired products, which are obtained as mixtures of isomers, is also expensive. This treatment involves multiple extraction and distillation of solvents, as well as chromatographic separation. Thus, the above synthesis is not very suitable for the preparation of 3- (2-chloro-2-arylvinyl) -2,2-dimethylcyclopropane-1-carboxylic acid esters on an industrial scale and should be replaced by a more easily feasible process.

The present invention relates to a process for the preparation of 3- (2-arylvinyl) -2,2-dimethylcyclopropane-1-carboxylic acid esters of the general formula I,

in which

Ar is a phenyl radical optionally substituted by one or more of the same or different substituents X selected from the group consisting of fluoro, chloro, bromo, cyano, nitro, C 1 -C 4 alkyl, C 1 -C 2 alkoxy, thio alkyl C 1 -C 2, trifluoromethyl, C 1 -C 2 fluoroalkoxy or C 1 -C 2 chlorofluoroalkoxy, trifluoromethylthio, methylenedioxy, difluoromethylenedioxy, ethylenedioxy, difluoro, trifluoro and tetrafluoroethylene;

R ¹ represents a hydrogen atom or a halogen atom;

R is C 1 -C 4 alkyl, characterized in that the 1-aryl-4-methylpenta-1,3-dienes of formula II are:

(II) in which

Ar and R1 are as defined above, reacted with the diazoacetic acid esters of formula III,

N ₂ CH-C00-R (IIX) wherein

R is as defined above, in the presence of a catalyst at a temperature between 50 and 200 ° C.

The invention further relates to a process for the production of the various starting materials and intermediates mentioned below and for the purpose of identifying the numbers indicated by (3) to (7).

Accordingly, the present invention also provides a process for the preparation of 1-halo-1-aryl-4-methyl-penta-1,3-dienes of the above formula (II) wherein Ar is as defined above and R ¹ is a halogen atom, characterized in that characterized in that the 3-methylbuten-2-ylaryl ketones of the formula IVa and / or the isomeric 3-methylbuten-1-ylarylketones of the formula IVa

IVb,

(IVb) in which:

Ar is as defined above, reacted with phosphorus pentachloride, optionally using an inert diluent, at a temperature between -40 and +30 ° C, after which the reaction mixture is treated at the same temperature with an acid binding agent, optionally in the presence of a catalyst / process. , (3) /.

The invention further provides a process for the preparation of 1-aryl-4-methylpenta-1,3-dienes of the above formula II, wherein Ar and R ¹ are as defined above, characterized in that the arylmethanephosphonic acid esters of formula V,

II ₂

Ar-CH-P (OR% (V) +)

in which

Ar and R ¹ have the abovementioned meaning and

R ² represents alkyl or phenyl or both radicals R ² together form a straight or branched alkanediyl, is reacted with the Formula VI dimethylakroleinem

(VI) in the presence of a base and optionally using a diluent, at a temperature between -70 to 150 ° C (process (4)).

The invention also provides a process for the preparation of formula (II) wherein Ar and R1 have beta-arylacroleins of formula (VII),

1-aryl-4-methylpenta-1,3-dienes as defined above, characterized in that

Ar-OCH-CHO

1.

in which

Ar and r 'are as defined above, reacted with a trieenyl-ioopoopyl-10-ooanane of formula VIII, (VII)

(VII) optionally using diluents,. at a temperature between -70 and +50 ° C / procedure (5) //.

The invention further provides a process for the preparation of the α1β1-4-methylpental-1,3-dienes of the above formula (II), wherein Ar is as hereinbefore defined, wherein the β-β-β-oleolole of the above formula (VVI) wherein Ar and R 'have the aforementioned meaning is reacted with isopropylmagnesium chloride chloride of formula IX,

(IX) optionally in the presence of diluents, at a temperature between + 70 ° C and + 50 ° C, and the resulting products are dehydrated by treatment with acids at a temperature between 0 ° C and 50 ° C (process (6)).

Finally, the invention describes a process for the preparation of the beta-halo-beta-arplacroleins of the above-mentioned general formula (VII), in which Ar is as defined above and r 'is a halogen atom characterized in that

Ar-CO-CH ₃ (X) wherein

Ar is as defined above, reacted with dimethylformamide and losphosphorus oxyhalide at a temperature between 0 and 100 ° C without the addition of an additional diluent and the reaction products are isolated without distillation (procedure (7)).

New. surprisingly, the esters of 3- (2-arylvinyl) -1,2,2-dimethylcyclooroopene-1-carboxylic acid in good yields are obtained by the process of the present invention, which is less expensive than known and easy to prepare starting materials.

The preferred compounds which can be prepared by the process according to the invention are the 3- (4-chloro-4-aryl-vinyl) -1,2,2-limethylcyclopropane-11-acetylpolenic acid esters of the above general formula (I) in which:

Ar represents a lenyl radical optionally substituted at the 3 or 4 position by one or two of the same or different substituents X selected from the group consisting of fluorine, chlorine and bromine, methyl, mmthose, methylthio, trifluoromethyl, trifluoromethyl group,. trlllooraetayltai group, mmthylenedioxy group, difluoraetaylenedioxy group and trlfjoprtapyeedioxy group,

R 'předstawiee aomm chlorine! and

R is methyl or ethyl.

Formula I includes various isomers and mixtures thereof. The compounds of the formula I are partly known insecticides and partly intermediates for the preparation of insecticides.

If, for example, 1-chloro-1-phenyl-4-methylpentadiene and ethyl diazoacetic acid are used as starting materials in the process according to the invention, the reaction of these compounds can be described by the following reaction scheme:

/ CH ₃ ^X CH ₃ + n ₂ ch-co-oc ₂ h ₅

h ₃ c CH ₃

The compounds used in the process according to the invention as starting materials are defined as. II. and III. In these formulas, Ar, R ¹ and R are preferably the same radicals which have already been mentioned as being preferred for these symbols already in connection with the description of the compounds of the formula I.

The diazoacetic acid esters of formula (III) are known in the literature and are exemplified by the methyl ester and the ethyl ester of the diazoacetic acid.

The novel 1-aryl-4-methylpenta-1,3-dienes of formula (II) may be prepared according to the procedures of (3), (4), (5) and (6). Examples of compounds of formula II include:

1-phenyl-, 1- (4-fluorophenyl) -, 1- (4-chlorophenyl) -, 1- (4-bromophenyl) -, 1- (3-bromophenyl) -, 1- (3,4-dichlorophenyl) 1- (4-methylphenyl) -, 1- (3-trifluoromethylphenyl) - and 1- (4-trifluoromethylphenyl) -1-chloro-4-methylpenta-1,3-diene.

For example, a mixture of 2-methyl-5-oxo-5- (4-chlorophenyl) -2-pentene and 2-methyl-5-oxo-5- (4- chlorophenyl) -3-pentene, the reaction of these compounds with phosphorus pentachloride and the subsequent elimination of hydrogen chloride can be described by the following reaction scheme:

The starting materials used in the process (3) are defined by formulas IVa and IVb. Preferred and particularly preferred Ar moieties in these formulas are the same as those already described in the description of the compounds of formula I prepared by the process of the invention.

The starting materials of the formulas (IVa) and (IVb) are in part known and / or can be prepared in a manner known per se (see J. Org. Chem. 2 (1960), 272]. Compounds of formulas IVa and IVb are obtained, for example, by reacting the arylmethyl ketones of formula X above with 8 isobutyraldehyde and distilling the reaction product in the presence of sodium acetate.

Examples of arylmethylketones of formula X include acetophenone, 4-fluoroacetophenone, 4-chloroacetophenone, 4-bromoacetophenone and 4-methylacetophenone.

‘212349

The reaction in process (3) is carried out by adding phosphorus trichloride to the starting material of formula IVa or IVb or a mixture thereof in a diluent. In contrast to the general and well-known working methods for the reaction of ketones with phosphorochlorophosphorus chlorde (see Houben-Weyy, Methoden der organischschen Chemie, vol. 5/3, p. 912), the reaction in the reaction mixture (3) is preferably carried out in presence of diluent.

Suitable diluents are, for example, hydrocarbons, such as gasoline, petroleum ether, pentane, hexane, cyclohexane, benzene, toluene or xylene, chlorinated hydrocarbons, such as methylene chloride, dichloroethane or chloro benzene, and nitriles. , such as acctoni nril. Toluene and / or cyclohexane is preferably used as the diluent. The reaction of unsaturated ketones with chlorine phosphorotheil is virtually always problematic and can cause a large number of side reactions. Thus, for example, chlorination may occur in the allyl position or in the alpha position relative to the carbonyl group. Hydrogen chloride, which is produced here, as in the case of elimination, can again add to the double bond. In addition, chlorination of the double bonds can also occur with phosphorus chloride.

It has been found that these side reactions can be virtually eliminated by working in the presence of diluents and at a relatively low temperature, and then adding a base at the same or a lower temperature so as to prevent the presence of hydrogen chloride at higher temperatures. The reaction is generally carried out at a temperature between -40 and +30 ° C, preferably between -10 and +20 ° C.

As the acid-binding agents, practically all technically useful bases, such as hydroxides such as sodium and potassium hydroxides, sulfites such as sodium and potassium carbonates, as well as alkoxides such as mmeboxide or sodium ethoxide. Preferably, aqueous solutions of alkali metal hydroxides or alkali metal carbonates are used in the presence of the phase transfer catalysts. All conventional phase transfer catalysts may be used for this purpose, but preferably a tetraalkyl or arylalkyllammonium salt is used, for example benzyltrehallaniumichloride or tert-butylsuccinium fluoride.

The 1-chloro-1-aryl-4-methylpentyl-1, -dienes prepared in the mixture of process (3) can generally be purified by de-distillation. If these members cannot be de-distilled without decomposition, they are cleaned by so-called dsdeetilsaíii, ie by longer heating to moderate elevated temperature under reduced pressure.

If, for example, diethyl 4-trifluoromethylsulphonylphosphonic acid diethyl ester and dihydrohsacrolein are used as starting material in process (4), the reaction of these compounds can be described as follows:

O

H

CH 3 + C = CH-CHO --- * cJ

----> CF ₃ ^- ^ ^{2y -} c = 1 H-CH = c: 1

H

CH3

CH3

The starting materials used in the process (4) are defined by formulas V and VI. In these general formulas, preferably the ^{terms А АGГ} and R ^{ty are the} same radicals which have already been mentioned as preferred for these symbols in conjunction with the description of the compounds of formula (I) produced by the process (1) of the invention. The dietary salt of formula (VI) is a compound known from the art.

Some of the esters of arslitthanephosphonic acid of formula V are known. Those compounds in which R @ ¹ is halogen can be obtained by the reaction of alpha-hydrsxy-arslittha-n-ssfs7-esters of the novel acids of formula XI,

I 2

Ar-CH-P (0 R ‘), к (XI) in which o

Ar and R are as defined above, with a halogenating agent, for example thionyl chloride, at a temperature between 0 and 100 ° C, preferably between 20 and 60 ° C (see Chimia 28 (1974), 656-657); J. Am. Chem. Soc. 87 (1965), 2777-2778].

The alpha-hydroxy-arylmethanephephonic acid esters of formula XI are known in some cases. These compounds are prepared in a known manner, generally by reaction of the aldehydes of formula XII

Ar-CHO (XII) wherein

Ar is as defined above, with phosphorous acid esters of general formula (XIII)

O

HP (OR ¹ ) ₂ (XIII) wherein

R ^ is as defined above, optionally in the presence of a catalyst such as triethylamine, at a temperature between 0 and 150 ° C, preferably between 20 and 100 ° C (see Houben-Weyl, Methoden der organischen Chemie, 4th edition (1963)) , St. 12/1, pp. 475-483].

Examples of the aldehydes XII are: benzaldehyde, 4-chlorobenzaldehyde, 4-fluorobenzaldehyde, 3-bromobenzaldehyde, 4-bromobenzaldehyde, 3-chlorobenzaldehyde, 3,4-dichlorobenzaldehyde, 2,6-difluorobenzaldehyde and 4-methylbenzaldehyde.

Examples of phosphorous acid esters of formula (XIII) include dimethyl phosphorous ester and diethyl phosphorous ester.

The reaction of process (4) is a variant of the Wittig-Horner reaction. Very few examples are known for this variant. The base used in the prior art is sodium hydride, which is an expensive reagent that is difficult to handle. In accordance with the new process, on the other hand, it is possible to work considerably simpler and less costly. The reaction can be carried out at room temperature in an aqueous reaction medium, and cheaper bases can be used instead of sodium hydride.

The reaction of process (4) is preferably carried out using diluents. Suitable diluents are practically all inert organic solvents, including in particular aliphatic and aromatic and / or chlorinated hydrocarbons, such as gasoline, benzene, toluene, xylene, methylene chloride, chloroform, carbon tetrachloride, chlorobenzene and o-dichlorobenzene, ethers such as diethyl ether, dibutyl ether, tetrahydrofuran and dioxane, alcohols such as methanol, ethanol, n- and isopropanol, η-, iso-, sec- and tert-butanol as well as dimethylsulfoxide.

When working in a two-phase system, in addition to 50% aqueous sodium hydroxide, practically water-immiscible solvents such as gasoline, benzene or toluene are used.

Bases which are commonly used in the olefinization of carbonyl derivatives can be used. Examples of such bases include alkali metal hydroxides such as sodium and potassium hydroxides, alkali metal alkoxides such as methoxide, ethoxide, o- and isopropoxide, η-, iso-, sec and tert-butoxide of sodium and potassium, alkali hydrides metals such as aluminum hydride, and alkyl compounds such as butyl lithium. Preferably, the base used is sodium and potassium hydroxide, as well as sodium methoxide and sodium ethoxide.

Reaction temperatures are generally between -70 and +150 ° C, preferably between -10 and 50 ° C. The reaction is generally carried out under normal pressure. When working in accordance with process (4), the reaction components are usually seen in equimolar amounts, only the bases are usually used in a larger excess, when operating in a single-phase system in an excess of up to 30 mol. %, preferably up to 15 mol. When 50% sodium hydroxide is used as the second phase, a total of fifteen to fifteen times the stoichiometric ratio is generally employed.

The necessary alkoxides are optionally prepared by sieves from alcohols and alkali metals.

In general, a base and optionally a catalyst are introduced into one or more of the above solvents, and the reaction components, i.e., arylmethaephthrophenoic acid ester of formula V and di-acrolein of formula VI, optionally dissolved in any of the above, are added to the mixture respectively. of said disintegrants. To complete the reaction, the mixture was stirred at the above temperature for several hours. For work-up, the reaction mixture was diluted with water, optionally with hydrochloric acid, and extracted with methylene chloride. The tar phase is dried and the solvent is distilled off in vacuo. Alternatively, the product which is distillated as a residue is purified by vacuum dessillation or, in the case of a product which cannot be distilled without decomposition, by so-called post-distillation, i.e. longer heating under reduced pressure to moderate elevated temperature. The boiling point or hem index is used to characterize these products.

If the starting material of process (5) is used as starting material, for example beta-chloro-Ueta- (3-methylphenyl) acryl and itopropylphenyl], the reaction of these compounds can be described by the following scheme:

® Θ of ^CH3 + (CgHg ^P-C-CH3

CH3

The process for producing phosphorus of formula VIII is known.

The acroleic derivatives of the formula VII are known in part. A new method for their production, referred to as process (7), will be described below.

Out! the substances used in the process mixture (5) are defined by formulas VII and VIII. In these formulas, the preferred and particularly preferred radicals and the tubing of the radicals and substitutions mentioned in the description of the compounds of formula (I) prepared according to the process of the invention are described.

Examples of acroleia derivatives of the general formula VCI include: beta-phenethyl-, beta- (4-fluorophenyl) -] Ueta- (4-chlorophenyl) -] Ueta- (4-Uromphened) - and Ueta- (4-methylphenyl) - . ') akrnLeie, as well as the corresponding Ueta-crnraCroleied ·

The reaction of process (5) is carried out by conventional methods used in the olefinization of a Wittig carbonyl group.

When the starting materials beta-chloro-beta- (4-methylphenyl) acrolein and isopropylmagnesium chloride are used in the process (6), the reaction of these compounds can be described by the following scheme:

^CH3- / \ = -С СН СНО + ^3-CH-M ^ _g -Cl --- ►

I H-> C

Cl

Isopropylmagnesium chloride can be prepared by a known method (see Chem. Ber. 69 (1936), 1766].

The starting materials used in the process (6) are defined by formulas VII and IX. In these formulas, the preferred and particularly preferred radicals and substituents correspond to those already mentioned in the description of the compounds of formula I produced by the process of the invention.

Examples of acrolein derivatives of formula VII include: beta-phenyl-, beta- (4-fluorophenyl) -, beta- (4-chlorophenyl) -, beta- (4-bromophenyl) - and beta- (4-methylphenyl) acrolein as well as the corresponding beta-chloroacroleins.

Process (6) consists of a Grignard reaction followed by dehydration. The Grignard reaction may be carried out in a manner known per se. It is surprising that water can be eliminated relatively easily from the intermediate secondary alcohol formed. The dehydration is carried out by treatment with acids, preferably sulfuric acid, at a temperature between 0 and 50 ° C, preferably between 20 and 45 ° C. After pouring into water, the reaction mixture is worked up by conventional extraction.

If, for example, 4-fluoroacetophenone, dimethylformamide and phosphorus oxychloride are used as starting materials in process (7), the reaction is described as follows:

^POC, 3

H-CO-N _{(CH3) 2}

The aryl methyl ketones used in the process (7) as starting materials are defined by the formula X. In this formula, the preferred and particularly preferred radicals and substituents correspond to those already mentioned in the description of the compounds of the formula I prepared by the process according to the invention.

Examples of arylmethylketones of formula X include: acetophenone, 4-fluoroacetophenone, 4-chloroacetophenone, 4-bromoacetophenone, 4-methylacetophenone and 4-phenylacetophenone.

Process (7) yields the beta-haiogen-beta-erylacroleins of the general formula VII in particular simply and in an improved yield and quality when, in contrast to the data recommended by the literature / see Proc. Chem. Soc. (London) 1958,227; Angew. Chem. 71 (1959) 573; Chem. Ber. 93 (1960), 2746 and Chem. Ber. 98 (1965), 3554], does not add a diluent and does not undergo distillation treatment associated with considerable losses, and the products are isolated in crystalline form after gentle hydrolysis at low temperature.

The reaction according to process (7) is carried out by dissolving the ketone of the formula (X) in dimethylformamide, adding phosphorus oxychloride at a temperature between 0 and 100 ° C, preferably between 20 and 60 ° C, and stirring at the same temperature for 1 to 5 hours. The reaction mixture is poured into ice-water and the pH is adjusted to about 5 with caustic soda, ensuring that the temperature does not exceed 25 ° C. After stirring, the product is filtered off with suction, washed. water and dried in vacuo.

The reaction according to the invention is carried out in the presence of catalysts. Possible catalysts are copper and copper compounds in various oxidation stages, as well as mixtures thereof. Examples include copper (such as powder or bronze), cuprous chloride and cuprous chloride, cuprous oxide and cuprous oxide, as well as manganese sulfate. The reaction temperature can be varied within wide limits. In general, the reaction is carried out at a temperature of between 50 and 200 ° C, preferably between 80 and 150 ° C.

The process according to the invention is generally carried out under normal pressure and, in carrying out the process, the weight ratio of the starting materials can be within wide limits. In general, a weight ratio of diacetoacetic acid ester to 1-aryl-4-methylpta-1,3-diene of between 1: 1 and 1:20 is employed. Typically, 2/3 of the total amount of 1-aryl-4-methylpenta-1,3-diene (II) together with the catalyst is heated to the desired reaction temperature and then the di-acetic acid ester (III), diluted, is added dropwise. the remaining third of the member of formula II. After nitrogen evolution ceases, the reaction mixture is cooled, diluted with a water-immiscible solvent such as methylene chloride, and filtered. The filtrate was washed with water, dried and worked up by distillation. Boiling points are used to characterize the products.

The compounds of the formula I prepared according to the process of the invention can be used as intermediates for the preparation of insecticidally active compounds (cf. DOS No. 2,738,150).

The invention is illustrated by the following non-limiting examples.

He did

A mixture of 45.4 g (0.2 mol) of 1- (4-chlorophenyl) -1-chloro-4-methylpenta-1,3-diene, 1.2 g of copper powder and 1.5 g of anhydrous and tin sulphate is heated to 110 ° C and then 22.7 g (0.1 mol) of t-chlorophenyl) -1-chloro-4-methylpenta-1,3-diene are added dropwise very slowly over 5 hours at 110 ° C. and 34.2 g (0.3 mol) of diazoacetic acid ethyl ester. After nitrogen evolution ceased, the mixture was cooled, diluted with 500 ml of methylene chloride and filtered. The filtrate is shaken with 500 ml of water, the organic phase is separated, dried over magnesium sulphate and the solvent is distilled off under a water pump vacuum. The oily residue is fractionally distilled under vacuum to give two fractions:

fraction 1: boiling point 124-135 ° C / 267 Pa, fraction 2: boiling point 135-170 ° C / 267 Pa.

Fraction 1 consists of unreacted 1- (4-chlorophenyl) -1-chloro-4-methylpenta-1,3-diene. Fraction 2 was distilled again to give 11.2 g of 2,2-dimethyl-3- [2-chloro-2- (4-chlorophenyl) vinyl] cyclopropanecarboxylic acid ethyl ester (isomer mixture) as a yellow oil, b.p. 146 up to 170 ° C / 267 Pa.

The following compounds are obtained in an analogous manner:

Boiling point 140-150 ° C / 300 Pa.

Boiling point 135-145

H ₃ C ch ₃

Boiling point 160-175 ° C / 400 Pa.

Example 2

_X ^CH 3

Procedure (3) g of potassium hydroxide is dissolved in 125 ml of water and 125 ml of methanol, 155 g of 4-chloroacetophenone are added to the solution, and 80 g of isobutyraldehyde are added dropwise at 50 DEG C. over 1.5 hours.

After 3.5 hours, the mixture was cooled to room temperature and neutralized with about 20 mL of acetic acid. The dimeric condensation product is filtered off with suction, washed with methanol and air-dried. 185 g (88.5% of theory) of a solid are obtained, which are mixed with 5 g of sodium acetate and distilled under a water pump vacuum. 175 g of a yellow oil, solidified at room temperature, are obtained, containing 2-methyl-5-oxo-5- (4-chlorophenyl) -2-pentene and 2-methyl-5-oxo-5- (4-chlorophenyl) - 3-pentene. This mixture of isomers has a boiling point of 155-157 ° C / 1800 Pa.

104.25 g (0.5 mol) of the above mixture of isomers are dissolved in 500 ml of toluene and 104 g of phosphorus pentachloride are slowly added to the solution at 0 ° C. The mixture is stirred at 0 to 10 ° C until all the phosphorus pentachloride is dissolved, then 5 g of tetrabutylammonium bromide is added thereto and 224 g (2 mol) of 50% potassium hydroxide solution are added dropwise at 0 to 10 ° C with efficient cooling. . The toluene phase is then immediately separated, washed neutral and evaporated on a rotary evaporator. The crude diene is pre-distilled (boiling point 130-159 ° C / 27 Pa) and then purified by a second distillation. 67 g of 1- (4-chlorophenyl) -1-chloro-4-methylpenta-1,3-diene having a boiling point of 100 DEG to 109 DEG C./13 mbar are obtained.

In an analogous manner, from 2-methyl-5-oxo-5-phenyl-2 (3) -pentene (prepared according to J. Org. Chem. 22, atr. 272), 1-phenyl-1-chloro-4-methylpenta- 1,3-diene, boiling 92-96 ° C / 11 Pa.

Example

Cl

Cl

C = CH-CH

AND

Procedure (4)

4.6 g (0.2 mol) of sodium are dissolved in portions in 100 ml of dry ethanol. After dissolution of all sodium, 100 ml of anhydrous tetrahydrofuran was added and 59.4 g (0.2 mol) of 4-chloro-alpha-chlorobenzylphosphonic acid diethyl ester dissolved in 50 ml of anhydrous tetrahydrofuran was added dropwise at 0 ° C with stirring. The resulting mixture was stirred at 0-10 ° C for 1 hour, then 16.8 g (0.2 mol) of beta, beta-dimethylacrolein dissolved in 30 ml of anhydrous tetrahydrofuran was added dropwise with stirring. The reaction mixture is stirred at room temperature for 12 hours, then 600 ml of water are added and the resulting mixture is extracted twice with 300 ml of methylene chloride each time. The organic phase is separated, dried over magnesium sulphate, the solvent is distilled off under a water pump vacuum and the residue is distilled under vacuum. 25.2 g of 1- (4-chlorophenyl) -1-chloro-4-methylpenta-1,3-diene (mixture of isomers) is obtained in the form of a yellow oil which, after some time, crystallizes partially. The product has a boiling point of 125 to 134 ° C / 267 Pa.

Analogously, 1-phenyl-1-chloro-4-methylpenta-1,3-diene of the formula boiling in the range of 120-135 is obtained.

= CH-CH = C ° C / 267 Pa.

ch ₃

The alpha-hydroxybenzylphosphonic acid ester of the formula needed is the starting material

can be prepared as follows:

To a mixture of 20.7 g (0.15 mol) of diethyl phosphite and 1.09 g (0.0109 mol) of triethylamine was added p-chlorobenzaldehyde (21 g, 0.150 mol) over 1 hour while cooling with water at 50-70 ° C. The reaction mixture is stirred at 70 DEG C. for 1 hour and, after cooling, shaken with 40 g of toluene and washed several times with dilute hydrochloric acid and cold water. The organic layer was separated and the solvent was removed in vacuo. The solid residue melts at 70-72 ° C. The yield of 4-chloro-alpha-hydroxybenzylphosphonic acid diethyl ester is 37 g (88.5% of theory).

The following compounds can be obtained in an analogous manner:

Mp 75 ° C.

O-c-Ploc-OH o

Р- ^ У-СН-Р (ОС ₂ Н _{5) 2}

OH

Melting point 26 ° C.

Preparation of compound of formula

To a mixture of 20.2 g (0.0725 mol) of 4-chloro-alpha-hydroxybenzylphosphonic acid diethyl ester, 65 g of dichloromethane and 5.8 g (0.0725 mol) of pyridine are added at 20-40 ° C with moderate water cooling. over about 1 hour 9.2 g (0.0768 mol) of thionyl chloride. The reaction mixture was heated to reflux for 3 hours and then stirred for 12 hours without further heating. The resulting mixture is poured into about 100 g of water with ice, the organic base is separated and dried. After distilling off the solvent, the residue is evaporated at a pressure of 800 Pa at 45 ° C. 21 g (97> 7% of theory) of 4-chloro-alpha-chlorbenzylfosfonové acid as a viscous yellow oil having a purity of 98.6% (GC) and the refractive index n ²⁴ = 1.5250.

D

The following compound can be prepared in an analogous manner:

O

HP (OC ₂ H ₅ ) ₂ ci

Refractive index n ²³ * 1.5117.

D

Example 4

Cl

Procedure (5)

To a suspension of 22.7 g (0.0525 mol) triphenylisopropylphosphonium iodide in 100 ml tetrahydrofuran at 0 ° C was added dropwise 0.055 mol-butyllithium in 30 ml hexane. After stirring at 0 ° C for 1 h, a solution of 10.1 g (0.05 mol) of beta- (4-chlorophenyl) -beta-chloroacrolein in 100 ml of tetrahydrofuran was added in one portion, and the resulting mixture was stirred for 1 h. it was stirred at 20 ° C for 10 hours. The reaction mixture is evaporated, 100 ml of water are added to the residue, and the mixture is extracted twice with 50 ml of ether each time. The combined ether extracts were dried over sodium sulfate and evaporated. The residue is crystallized after the addition of about 50 ml of petroleum ether. The crystals are filtered off with suction and recrystallized again from petroleum ether.

8 g (70.5% of theory) of 1- (4-chlorophenyl-1-chloro-4-methylpenta-1,3-diene) are obtained in the form of pale yellow crystals, m.p.

Example 5

/ ^CH 3 ^X CH ₃

Procedure (6)

To a solution of 0.4 mol of isopropylmagnesium chloride in 40 ml of isopropyl chloride (prepared according to the procedure described by J. Houben et al. in Chem. Ber. 69 (1936), 1766), 40 g (0.2 mol) of beta-chloro-beta- (4-chlorophenyl) acrolein in 200 ml of tetrahydrofuran was added dropwise at 20 ° C.

The reaction mixture is stirred for a further 12 hours and then poured into a mixture of 500 g of ice and 100 ml of sulfuric acid with stirring. The resulting mixture was extracted twice with 100 ml of ether each time, the combined ether extracts were dried over sodium sulfate and evaporated on a rotary evaporator at 50 ° C. The residue is taken up in 50 ml of glacial acetic acid and 2 ml of concentrated sulfuric acid is added dropwise thereto at a rate such that the temperature does not exceed 45 ° C. The resulting mixture was stirred at 20 ° C for 4 hours and then poured into water. The aqueous mixture was extracted twice with 100 ml of ether each time, the combined ether extracts were dried over sodium sulfate, evaporated and the residue was distilled. 23 g of 1- (4-chlorophenyl) -1-chloro-4-methylpenta-1,3-diene are obtained in the form of a yellow oil which partially crystallizes on cooling. The product boils at 140 to 145 ° C / 533 Pa.

Example 6

Procedure (7)

772.5 g (5 mol) of 4-chloroacetophenone are dissolved in 2.5 l of dimethylformamide and 1570 g of phosphorus oxychloride are added dropwise over a period of 2 hours at 40-45 ° C with gentle cooling. The mixture is stirred for 1 hour, then poured into 25 l of water 8 with ice and added dropwise for ca.

The pH was adjusted to 5 with 2.1 L of concentrated sodium hydroxide solution. During neutralization, the temperature was kept below 25 ° C by dropping ice pieces. The resulting mixture was stirred for an additional 1 hour at pH 5 and below 25 ° C. The pale crystalline precipitate is filtered off with suction, washed thoroughly with water and dried under vacuum at 50 ° C. Yield 740 g (74%). The product melts at 98 ° C.

Claims (1)

SUBJECT OF THE INVENTION Process for preparing 3- (2-arylvinyl) -2,2-dimethylcyclopropane-1-carboxylic acid esters Ar = C = CH CO-O-R (I) wherein Ar is a phenyl radical optionally substituted by one or more of the same or different X substituents selected from the group consisting of fluorine, chlorine, bromine, cyano, nitro, C 1 -C 4 alkyl, C 1 -C 2 alkoxy, alkyl thio groups C 1 -C 2, trifluoromethyl, C 1 -C 2 fluoroalkoxy or C 1 -C 2 chlorofluoroalkoxy, trifluoromethylthio, methylenedioxy, difluoromethylenedioxy, ethylenedioxy, difluoro, trifluoro and tetrafluoroethylenedioxy R ¹ represents a hydrogen atom or a halogen atom; R is C 1 -C 4 alkyl, characterized in that the 1-aryl-4-methylpenta-1,3-dienes of formula II are: Ar-C = CH-CH-C (II) wherein Ar and R ¹ have the abovementioned meaning, are reacted with diazoacetic acid ester of formula III, n ₂ CH-COO-R (III) wherein R is as defined above, in the presence of a copper catalyst or compounds thereof, at a temperature between 50 and 200 ° C.