NO781112L - PROCEDURES FOR THE PREPARATION OF 2- (2`, 2`, 2`-TRIHALOGENETHYL) -4-HALOGENCYCLOBUTAN-1-ONERS - Google Patents

Description

The present invention relates to a process for the production of 2-(2',2<1>,2<1->trihaloethyl)-4-halo-cyclobutan-1-ones of formula I

where one of the residues R and means methyl and the other

hydrogen or methyl or R, and R2 together form an alkylene group of 2 to 4•carbon atoms and X and Y are chlorine. or bromine whereby, when X is bromine, X must always be bromine.

The present invention further relates to the new, according to the method according to the invention, produce only 2-(21,2',2',-trihaloethyl)-4-halocyclobutan-1-one of formula I as well as the new intermediates that can be used for production hence.

It is known that ct-halocycloalkanones, when heated in the presence of bases such as alkali metal hydroxides or alkali metal alcoholates, undergo ring narrowing to cycloalkanecarboxylic acids with the same carbon number or esters thereof (Favorski reaction). This reaction forms the arunn layer for a technically important process for the production of cyclopropane carboxylic acid derivatives and their insecticidally active esters, the pyrethroids, from α-halocyclobutanones. However, the application of this technically easy-to-implement process for the production of pyrethroids derived from 2-(2', 2'-dihalovinyl)-cyclopropanecarboxylic acid was not possible, as correspondingly suitable α-halocyclobutanones were not available for the production of such cyclopropanecarboxylic acid derivatives. ^

It has previously been proposed to prepare ci-halocyclobutanones by reacting the et.haloketene with an olefin.

Such a method is e.g. described in DOS 2,539,048, British patent 1,194,604 as well as in J. Amer. Chem. Soc. 87, 5257-5259 (1965) and in Tetrahedron Letter No. 1, 13.5-159

(1966). This synthesis principle has so far not been used for the production of α-halobutanones which are used as intermediate products in the production of 2-(2', 2'-dihalogenovinyl)-cyclopropanecarboxylic acids and their insecticidally active esters. This can primarily be attributed to the On the basis of the aforementioned method conceivable synthesis possibilities, namely

a) reaction of a halogenated olefin with a haloketene according to the equation:

or

b) reaction of a non-halogenated olefin with a halogenated ketene add to the equation:

where the symbols R , R0, X and Y in the above equation have the indicated meanings of the symbols R^, , X oq Y under formula

I, does not lead to the necessary intermediates 2-(2',2',2l<->trihaloethyl)-4-halocyclobutan-1-ones of formula I, since the reaction according to a) due to the deactivation of the olefin associated with the halogen substitution does not take place and the reaction according to b) gives a 2-(22',2'-trihaloethyl)-2-halocyclobutan-1-^one which cannot be transferred into a 2-(2',2'-dihalogenovinyl)-cyclopropanecarboxylic acid, respectively esters thereof.

The task for the present invention therefore lies in

on the basis of easily available starting material to provide a simple feasible method for the production of 2-(21,2 1,2'-trihaloethyl)-4-halocyclobutan-1-ones of formula I.

Furthermore, the task of the present invention is to provide the hitherto unknown 2-(2', 2V, 2'-trihalogenethyl)-4-halocyclobutan-1-ones of formula I which, when heated with strong bases such as alkali metal hydroxides or alkali metal alcoholates under ring narrowing and simultaneous cleavage of 2 moles of hydrogen haloaenide gives the corresponding 2-(2',2<1->dihalogenovinyl)-cyclopropanecarboxylic acid derivatives. as well as in the preparation of α-halocyclobutanones of formula I usable, easily accessible intermediates.'

It has now been found that 2-(22',2<1->trihaloethyl)-4-halocyclobutan-1-ones of formula I can be prepared in a simple way when reacting a 2,4,4,4-tetrahalobutyric acid chloride of formula II

where X and Y have the meaning given under formula I<q>in the presence of an organic base with an olefin of formula III where R-^ and R2 have the meaning given under formula I to a 2-(2•,2<1> ,2'-trihaloethyl)-2-halocyclobutan-1-one of formula IV where R 1 , R 2 , X and Y have the meaning given under formula I, and then it rearranges in the presence of a catalyst, in a 2-( 2<1>,2',2'-trihaloethyl)-4-halocyclobutan-1-one of formula I. 2,4,4,4-tetrahalobutyric acid chloride of formula II are new compounds. They can be prepared in a manner known per se by adding a tetrahalomethane of formula V where X and Y have the meaning given under formula I to . a compound of formula VI where Z means chlorocarbonyl, carboxyl, alkoxycarbonyl with 1 to 4 carbon atoms in the alkyl group or cyano, and transfers obtained compounds of formula VII where X and Y have it under formula. In the given meaning and Z means carboxyl, alkoxycarbonyl or cyano in the compounds with formula VII where Z means chlorocarbonyl. A further possibility for the production of 2,4,4,4-tetrahalobutyric acid chlorides of formula II consists in adding a compound of formula Via where Z has the meaning given under formula VI to a . 1,1-dichloroethylene and transfers the obtained compounds of formula Vila

where Z means carboxyl, alkoxycarbonyl or cyano i

compound of formula Vila where Z means chlorocarbonyl.

In the addition of a tetrahalomethane of formula V to a

.acrylic acid derivative of formula VI as well as by the addition of a dichloroacetic acid derivative of formula Via to 1,1-dichloroethylene

the tetrahalomethane of formula V or the dichloroacetic acid derivative of formula Via can be used in a stoichiometric amount. Preferably, however, an excess of tetrahalomethane of formula V or the dichloroacetic acid derivative of formula Via is used, e.g. an approx. 0.5 to 2 times molar excess, whereby the tetrahalomethane of formula v can also serve as solvent.

The addition of a tetrahalomethane of formula V to a compound of formula VI as well as the addition of a compound

of formula Via to 1,1-dichloroethylene is carried out in the presence of catalyst. Metals from main group VIII and side groups Via, Vila and Ib in the periodic system are suitable as catalysts, e.g. iron, cobalt, nickel, ruthenium, rhodium, palladium, chromium, molybdenum, manganese and copper. These metals can be used in elemental form or in the form of compounds. Suitable compounds of these metals are e.g. oxides, halides, sulphates, sulphites, sulphides, nitrates, acetates, citrates, carbonates, cyanides and rhodanides,

as well as complexes with ligands such as phosphines, phosphites, benzoin, benzoyl and acetylacetonates, nitriles, isonitriles and carbon monoxide.

As examples of compounds of the aforementioned metals

which are suitable for catalysts are mentioned:

Copper(II) oxide, iron(III) oxide, Cu(I)- Cu(II)- Fe(II)- and Fe(III) bromide. and above all chlorides as well as chlorides of ruthenium, rhodium, palladium, cobalt and nickel, Cu(II) sulphate, Fe(II) and Fe(III) sulphate, Cu(II) nitrate and iron(III) nitrate, manganese(III) acetate, copper(II) acetate, copper(II) stearate, iron-(Ill) citrate, Cu(I) cyanide, ruthenium(II) dichloro-tris-triphenyl-phosphine, rhodium-tris(triphenylphosphine) chloride, chromium and nickel acetylacetonate, copper(II) acetylacetonate, iron(III) acetyl, acetonate, cobalt(II) and cobalt(III) acetylacetonate, manganese (II) acetylacetonate, copper(II) benzoylacetonate, iron carbonyl cyclo<p>entadienyl complex, molybdenum carbonyl cyclopentadienyl complex, chromium tricarbonylaryl complex, ruthenium(II) acetate complex, chromium and molybdenum hexacarbonyl, nickel tetracarbonyl, iron pentacarbonyl, cobalt and manganese carbonyl.

Mixtures of the aforementioned metals with metal compounds and/or other additives can also be used, such as copper powder in combination with one of the aforementioned copper compounds, mixtures of copper powder with lithium halides, such as lithium chloride or with isocyanides such as tert-butyliso-. cyanide, mixtures of iron powder with iron (III) chloride, possibly with the addition of carbon monoxide, mixtures of iron (III) chloride and benzoin, mixtures of iron (II) or iron (III) chloride and trialkyl phosphites, mixtures of iron pentacarbonyl and iodine.

Preferred are iron (II) and iron (III) salts and complexes as well as iron powder, above all, however, copper powder, copper (I)

and copper(II) salts and complexes, such as Cu(I) chloride, Cu(II) chloride, Cu(I) bromide,.Cu(II) bromide, Cu(II) acetylacetonate, Cu(II) benzoylacetonate, Cu (II) sulfate, Cu(II) nitrate and Cu(I) cyanide.

Particular preference is given to copper powder, copper (I) and copper (Il) chloride and bromide, respectively, and mixtures thereof.

The aforementioned catalysts are generally used in amounts from approx. 0.01 to 10 mol%, preferably 0.1 to 5 mol% calculated on the compound of formula III or 1,1-dichloroethylene respectively.

The addition reaction is carried out in an organic solvent. Suitable organic solvents are those in which the catalysts are sufficiently soluble or which can form complexes with the catalysts which, however, are inert towards the starting compounds. Examples of such solvents are alkylnitriles, especially those with 2-5 C atoms, such as acetonitrile propionitrile and butyronitrile, 3- alkoxypropionitrile with 1 or 2 C atoms in the alkoxy part such as 3-methoxypropionitrile and 3-ethoxypropionitrile, aromatic nitriles above all benzonitrile, aliphatic ketones with preferably a total of 3-8 C atoms such as acetone, diethyl ketone, methyl-isopropyl ketone, diisopropyl ketone, methyl tert-butyl ketone, alkyl and alkoxyalkyl esters of aliphatic monocarboxylic acids with a total of 2-6 C atoms such as formic acid methyl- and ethyl esters, acetic acid methyl-,. ethyl, n-butyl and isobutyl ester as well as 1-acetoxy-2-methoxyethane, cyclic ethers such as tetrahydrofuran, tetrahydropyran and dioxane, dialkyl ethers with 1-4 C atoms in the alkyl part such as diethyl ether, di-n-pro<p >yl ether and di-iso<p>ropyl ether, N,N-dialkylamides of aliphatic monocarboxylic acids with 1 to 3 C atoms in the acid part, such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide and ( hexametapol).

Preferred solvents are alkylnitriles with 2-5 C atoms and 3- alkoxypropionitrile with 1 or 2 C atoms in the alkoxy part, especially acetonitrile and 3-methoxypropionitrile.

The re-ion temperature is generally not critical and can vary within wide limits. Preferably, the reaction

the temperature between approx. 60 and 200°C, especially between approx.

00 and 170°C.

Acrylic acid chloride and dichloroacetyl chloride are used as compounds with formula VI and Via respectively. Thereby, the desired 2,4,4,4-tetrahalobutyric acid chloride is obtained directly in pure form and with high yields. Further preferred compounds with the formulas VI and Via are acrylic acid and dichloroacetic acid, respectively. The free 2,4,4,4-tetrahalobutyric acids thus obtained can then be easily transferred in a manner known per se by reaction with inorganic acid chlorides such as phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride, phosgene and thionyl chloride in the corresponding acid chlorides.

The esters or nitriles of a 2,4,4,4-tetrahalobutyric acid of formula VII (Z = alkoxycarbonyl or cyano) obtained by using compounds of formula VI or Via in which Z stands for alkoxycarbonyl or cyano are then hydrolyzed in the presence of strong acids such as concentrated hydrochloric acid to corresponding free 2,4,4,4-tetrahalobutyric acids, which are then transferred in a previously known manner into the corresponding acid chloride.

The reaction of 2,4,4,4-tetrahalobutyric acid chlorides of formula II with olefins of formula III is advantageously carried out in the presence of an inert organic solvent. As such, e.g. optionally halogenated aromatic or aliphatic hydrocarbons such as benzene, toluene, xylenes, chlorobenzene, dichloro- and trichlorobenzenes, n-pentane, n-hexane, n-octane, methylene chloride, chloroform, carbon tetrachloride, 1,1,2,2-tetra- . chloroethane and trichlorethylene. Further suitable solvents are cycloaliphatic hydrocarbons such as cyclopentane or cyclohexane, cycloaliphatic ketones such as cyclopentanone and cyclohexanone as well as aliphatic ketones, aliphatic and cyclic ethers, alkylnitriles and 3-alkoxypropionitrile with 1 or 2 carbon atoms in the alkoxy group, especially acetonitrile and 3-methoxypropionitrile.

Particularly suitable solvents are aliphatic, cycloaliphatic and aromatic hydrocarbons, above all alkane with 5-8 carbon atoms, benzene and toluene and especially n-hexane and cyclohexane.

However, an excess of olefin with formula III can also work as a solvent.

Suitable organic bases in the presence of which the reaction of a 2,4,4,4-tetrahalobutyric acid chloride of formula II with an olefin of formula III is carried out are e.g. tertiary amines, above all trialkylamines with 1 to 8 carbon atoms, especially 2 to 4 carbon atoms in the alkyl group, cyclic amines such as pyridine, quinoline, A-alkyl-pyrrolidines, N-alkyl-piperidirines, N,N-dialkyl-piperazines and N-alkyl -morpholines or dialkyl^anilines with 1 or 2 carbon atoms in the alkyl group such as N-methyl-pyrrolidine, N-ethyl-<p>iperidine, N,N'-dimethyl-piperazine, N-ethyl-morpholine and N,N-dimethylaniline as well as bicyclic' amidines such as 1, 5-diazabicyclo [ 5 . 4. 0 ] undec-5-ene and 1, 5-rdiazabicyclo-[4.3.0]non-5-ene and bicyclic diamines such as 1,4-diazabicyclo[2.2.2]octane.

The reaction of 2,4,4,4-tetrahalobutyric acid chlorides of formula II with olefins of formula III is preferably carried out in the presence of trialkylamines with 1 to 4 carbon atoms in the alkyl group. Particularly suitable bases are triethylamine and pyridine.

The organic amount is used in at least an equimolar amount or in a small excess calculated on 2,4,4,4-tetrahalobutyric acid chloride with formula II.

The olefins of formula III are likewise used in at least equimolar amounts - calculated on 2,4,4,4-tetrahalobutyric acid chloride of formula II. However, it is generally an advantage to use an excess of the olefin, whereby the olefin, as already mentioned, can also serve as a solvent. When using easily volatile olefins, the reaction can be carried out under pressure.

As an olefin of formula III, those in which one of the residues R-^ and means methyl and the other hydrogen or methyl or and R» together are an alkylene group with 2 to 3 carbon atoms, namely isobutylene, propene, methylenecyclopropane and methylenecyclobutane. Particularly preferred are isobutylene and methylenecyclopropane.

The reaction temperatures can vary within wide limits. They are generally between 0 and 200°C, preferably between 20 and 160°C.

2-(2',2',2',-trihaloethyl)-2-halocyclobutan-1-one with formula IV are likewise new compounds.. As catalysts for. rearrangement of the obtained 2-(2<1>,2',2'-trihaloethyl)-4-cyclobutan-1-one with formula i, acids, bases or quaternary ammonium halides can be used.

The rearrangement according to the invention of 2-(2<1>,2',2'-trihaloethyl)-2-halocyclobutan-1-ones of formula IV in 2-(2',2',2'-trihaloethyl) -4-halogenocyclobutan-1-one of formula I is unexpected and not known from α-position monohalogenated cyclobutanones. It is particularly surprising that during the rearrangement in the presence of a basic catalyst, ingeri HX elimination occurs in the trihaloethyl group. The resettlement takes place in the ex-mark, often with quantitative yield.

The rearrangement according to the invention of 2-(2',2',2'-trihaloethyl)-2-halocyclobutan-1-ones of formula IV in 2-(2,2',2'-trihaloethyl)-4-halocyclobutane -l-ones of formula I are preferably carried out in the presence of basic catalysts. As basic catalysts, organic bases come into consideration as primary, secondary and especially tertiary amines with the formula

where Q1 means alkyl of 1 to 8 carbon atoms, cycloalkyl of 5 to 6 carbon atoms, benzyl or phen<y>1 and Q2 and Q3 independently of each other mean hydrogen or alkyl of 1 to 8 carbon atoms. Suitable basic catalysts are e.g.

triethylamine, tri-n-butylamine, tri-isopentylamine, tri-n-octylamine, N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, N,N-dimethyl-2-ethylhexylamine, N,N-diethylaniline, as well further cyclic amines such as pyridine, quinoline, lutidine, N-alkylmorpholine such as N-methylmorpholine, N-alkylpiperidine, which

N-methyl-<p>g N-ethylpiperidine, N-alkylpyrrolidine such as N-methyl and N-ethylpyrrolidine, diamines such as N ,N,N',N'-tetramethylethylenediamine, N,N,N ' ,N' - te tr ame ty 1-1,3-diaminobutane,. N,N'-dialkyl-piperazine as N,N'-dimethylpiperazine, bicyclic amide as

1.4- diazabicyclo[2.2.2]octane and bicyclic amides such as 1.5-diazabicyclo[5.4.0]undec-5-ene and 1,5-diazabicyclo[4.3.0]non-5-ene and finally polymer basic compounds such as p- dimethylaminomethylpolystyrene.

Furthermore, as basic catalysts for the rearrangement according to the invention of a 2-(2',2<1>,2'-trihaloethyl)-2-halo-cyclobutan-1-one of formula IV in a 2-(2',2' ,2'-trihaloethyl)-4-halocyclobutan-1-one of formula I suitable phosphines, especially trialkylphosphines, e.g. tributylphosphine.

As acid catalysts for the rearrangement of 2-(2',2',2<1->trihaloethyl)-2-halocyclobutan-1-one of formula IV into tri-haloethyl)-2-halocyclobutan-1-one of formula IV in 2-(2',2',2'-trihaloethyl)-4-halo-cyclobutan-1-one of formula I, inorganic or organic protonic acids can be used. Suitable inorganic proton acids are e.g. hydrohalic acids such as hydrogen chloride, hydrogen bromide, hydrogen fluoride. and hydrogen iodide, nitric acid, phosphoric acid and sulfuric acid. Preferred inorganic protonic acids are hydrohalic acids.

If acids or bases are used in excess, they can also be used as solvents.

Furthermore, salts of protonic acids, in particular hydrogen halide acids such as ammonia or a nitrogen-containing organic base as well as quaternary ammonium halides, quaternary phosphonium halides and sulfonium halides can be used. As nitrogen-containing organic bases suitable aliphatic,. cycloaliphatic, j araliphatic and aromatic primary, secondary and tertiary amines as well as heterocyclic nitrogen bases. Examples include: primary aliphatic amines with up to 12 C atoms. such as methylamine, ethylamine, n-butylamine, n-octylamine, n-dodecylamine, hexamethylenediamine, cyclohexylamine, benzylamine, secondary aliphatic amines with up to 12 C atoms such as dimethylamine, diethylamine, di-n-propylamine, dicyclohexylamine, pyrrolidine , piperidine, piperazine, morpholiri, tertiary aliphatic amines, especially trialkylamines with 1-4 C atoms in the alkyl parts such as triethylamine, tri-n-butylamine, N-methyl-pyrrolidine, N-methyl-morpholine, 1,4-diazabicyclo 2.2.2]octane, quinuclidine, optionally substituted primary secondary and tertiary' aromatic amines, such as aniline, toluidine, naphthylamine, N-methylaniline, diphenylamine and N,N-diethylaniline, further pyridine, picoline, indoline and quinoline.

As quaternary phosphonium halides, e.g. in consideration: hexadecyltributylphosphonium bromide, methyl and ethyl triphenylphosphonium bromide, as sulfonium halide, e.g. trimethylsulphorium iodide.

Salts with the formula are preferred

where

M means fluorine, bromine or iodine, especially chlorine,

0 hydrogen, alkyl with 1-18 C atoms, cyclohexyl, benzyl

phenyl or naphthyl and

Qc, Q and Q-, independently of each other hydrogen ■ or alkyl

"stay/

with 1-18 C atoms,

as well as N-alkyl pyridine halides with 1-18 C atoms in the alkyl part', especially the corresponding chlorides.

Examples of such salts are: ammonium chloride, ammonium bromide, methylamine hydrochloride, cyclohexylamine hydrochloride, aniline hydrochloride, dimethylamine hydrochloride, di-isobutylaminohydrochloride

chloride, triethylamine hydrochloride, triethylamine hydrobromide, tri-n-octylamine hydrochloride, benzyl-dimethylamine hydrochloride, tetramethyl-, tetraethyl-, tetra-n-propyl-, tetra-n-butylammonium chloride, - bromide and -iodide, trimethyl-hexadecyl-■ ammonium chloride, benzyldimethylhexadecylammonium chloride, benzyldimethyltetradecylammonium chloride, benzyl-trimethyl-, -triethyl- and tri-n-butylammonium chloride, n-butyl-tri-n-propylammonium bromide, octadecyltrimethylammonium bromide, phenyltrimethylammonium bromide or chloride, hexadecylpyridine bromide and chloride.

As additional Co catalysts, 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, sodium fluoride and lithium fluoride can be used.

These .Co catalysts also catalyze the reaction without the above ammonium salts, however the addition of open-chain or macrocyclic polyethers (Kronenather) is an advantage for a fast course. Examples of such crown ethers are: 15-crown-5,18-crown-6,dibenzo-18-crown-6,dicyclohexyl-18-crown-6,5,6,14,15-dibenzo-7,13-diaza- 1,4-dioxa-cyclopene-tadeca-5,14-diene.

The amount of catalyst used can vary within wide limits. In many cases, it is sufficient when the catalyst is present in small quantities. In general, however, the catalyst is preferably used in an amount from approx. 0.1 to 15% by weight calculated for the compound of formula VI.

The redeposition can be carried out both in melt and in an inert organic solvent. The reaction temperature for the rearrangement in melt is generally between approx. 60 and 150°C, especially approx. 80 and 130°C.

For the rearrangement in the melt, suitable catalysts above all are the aforementioned organic bases, especially trialkylamines with 1-8 C atoms in the alkyl parts, further salts of hydrogen-

halide acids with ammonia or organic nitrogen-containing bases such as trialkylamine hydrochlorides and bromides with 1-8 C atoms in the alkyl parts and especially tetraalkylammonia halides, above all chlorides, bromides and iodides with 1-18 C atoms in the alkyl parts.

Suitable inert organic solvents are e.g.

- 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, nitromedan, chlorobenzene , dichlorobenzene and trichlorobenzene; - lower aliphatic alcohols, e.g. those with up to 6 C atoms such as methanol, ethanol, propanol, isopropanol, butanols and pentanols; - aliphatic diols such as ethylene glycol and diethylene glycol;

- ethylene glycol monoalkyl ether and diethylene glycol monoalkyl-

ether with up to 1-4 C atoms in the alkyl part such as ethylene glycol monomethyl and monoethyl ether, diethylene glycol monomethyl and monoethyl ether;

- cyclic amines such as N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone and N-methyl-£-caprolactam; - amides of carboxylic acid such as tetramethylurea and dimorpholinocarbonyl; - amides of phosphoric acid, phosphoric acid, phenylphosphoric acid or aliphatic phosphonic acids with 1-3 C atoms in the acid part such as phosphoric acid triamide, phosphoric acid tris(dimethylamide), phosphoric acid trimorpholide, phosphoric acid tripyrrolinide, phosphoric acid bis(dimethylamide)-morpholide, phosphoric acid dimethylamide-diethylamide- morpholide, phosphoric acid tris(dimethylamide), tetramethyldiamide of methanephosphonic acid;

- amides of sulfuric acid, of aliphatic or aromatic sulfonic acids such as tetramethylsulfamide, dimethylamide of methanesulfonic acid or p-toluenesulfonic acid amide; - sulfur-containing solvents such as organic sulphones and sulphoxides, e.g. dimethyl sulfoxide<p>g sulfolane; -aliphatic and aromatic hytriles, 3-alkoxypropionitrile, aliphatic ketones, alkyl and alkoxyalkyl esters of aliphatic monocarboxylic acids, cyclic ethers, dialkyl ethers, N,N-disubstituted amides of aliphatic monocarboxylic acids and ethylene glycol and diethylene glycol dialkyl ethers of. the type mentioned under method step 1).

For the rearrangement in the presence of an acid catalyst use

polar solvents are advantageously used, especially lower alcohols such as methanol, ethanol and butanols, N,N-dialkylamides of aliphatic monocarboxylic acids with 1-3 C atoms in the acid part, especially N,N-dimethylformamide or dialkylsulfoxides such as dimethylsulfoxide.

In aprotic, strongly polar solvents such as the aforementioned N,N-disubstituted amides of aliphatic monocarboxylic acids, cyclic amides, amides of carboxylic acids, amides of phosphoric acid, phosphoric acid, phenylphosphonic acid or of aliphatic phosphonic acids, amides of sulfuric acid or of aliphatic or aromatic sulphonic acids as well as dialkyl sulphoxides such as dimethyl sulphoxide, the reaction also proceeds without the addition of base or acid. In these cases, the solvent acts as a catalyst.

In general, however, a catalyst is added when re-laying in the presence of an inert organic solvent, preferably

. an organic base with a pK value below 9, in particular trialkylamines with 1-8 C atoms in the alkyl parts such as triethylamine, tri-n-butylamine and tri-n-octylamine, further hydrogen halide acids, especially HC1 and HBr as well as tetraalkyl ammonium halides , especially -chlorides, -bromides and -iodides I

with 1-18 C atoms in the alkyl part.

Particularly preferred solvents are aliphatic alcohols with 1-4 C atoms. toluene, xylenes, chlorobenzene, dioxane, acetonitrile, 3-methoxypropionitrile, ethylene glycol diethyl ether and diisopropyl ketone.

The reaction temperatures for the rearrangement in the presence of a

inert organic solvent is generally between approx. 0 and 150°C, preferably between approx. 80 and 130°C.

With the method according to the invention, new 3-position substituted 2-(2',2',2'-trihalo-ethyl)-4-halo-cyclo-•butan-1-ones of formula I are obtained which are suitable as intermediates for the preparation of 2-(2',2'-halovinyl)-cyclopropanecarboxylic acid derivatives substituted in the 3-position accessible from the available starting material in a simple manner and in good yield. The process according to the invention is particularly suitable for the production of 2-(2',2',2<1->trichloroethyl)-4-halocyclobutan-1-ones of formula I substituted in the 3-position. The course of the process according to the invention is extremely surprising and certainly not to foresee that when reacting a 2,4,4,4-tetrahalobutyric acid chloride of formula II or one of them, by cleavage of hydrogen chloride in situ formed haloketone with an olefin of formula III first one for the further conversion into a in the 3-position substituted 2-(2',2'-dihalovinyl)-cyclopropanecarboxylic acid derivative unehat 2-(21,21-trihaloethyl)-2-halocyclo- . butan-l-one with formula IV is formed, then by a new rearrangement which has previously been found with cyclobutanones which

is monohalogenated in the a-position is transferred in a suitable for further conversion into a 3-position substituted 2-(2',2'-dihalovinyl)-cyclopropanecarboxylic acid derivative 2-(2',2<1>,2<1 ->trihaloethyl)-4-halocyclobutan-1-one of formula I.

From new 2-(2',2',2'-trihalo)-4-chlorocyclobutan-1-ones of formula I prepareable in the 3-position substituted 2-(2!,2'-dihalovinyl)-cyclopropanecarboxylic acids and their

Insecticidally active esters can be described by the following formula VIII: where X, R^ and R^ have the meaning given under formula I because R is hydrogen, alkyl with 1 to 4 carbon atoms or the group with formula IX

where R^ means oxygen, sulfur or the vinylene group, R^ hydrogen, alkyl with 1 to 4 carbon atoms, benzyl, phenoxy or phenylmercapto, R^hydrogen or an alkyl group with 1 to 4 carbon atoms and Rg hydrogen, cyano or ethynyl

or, when. one of the residues R^ and R2 is methyl and the other hydrogen or methyl, R^ means the vinylene group, R^ is phenoxy and R^ hydrogen, also alkyl with 1 to 5 carbon atoms;

2-(2',2'-dihalovinyl)-cyclopropanecarboxylic acid derivatives of formula VIII where R represents a group of formula IX are suitable for combating various animal or botanical pests, especially insects. The properties, the areas of application

and the forms of application of these active substances are described

in the literature (compare e.g. Nature, 246, 169 - 170

(1973); Nature, 24J3, 710 - 711 (1974);'Proceedings 7th

British Insecticide and Fungicide Conference, 721-728

(1973); Proceedings 8th British Insecticide and Fungicide

Conference, 373-78 (1975); J. Agr. Food Chem. 23^, 115

(1973); US Patent 3,691,070; DOS 2,553,991, 2,439,177, 2,326,077 and 2,614,648.

The transfer of 2-(2',2<1>,2'-trihaloethyl)-4-halo-|.i

cyclobutan-I-ones of formula I in 2-(2',2'-dihalogenovinyl)-' cyclopropanecarboxylic acid derivatives of formula VIII occurs on

per se known manner by heating in the presence of suitable

bases. Suitable bases are e.g. alkali metal and alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide, calcium hydroxide and barium hydroxide. Also alkali metal-

and alkaline earth metal carbonates and hydrogen carbonates such as calcium carbonate, barium carbonate, potassium carbonate, sodium carbonate, sodium hydrogen carbonate and calcium hydrogen carbonate can be used as bases. Also suitable as bases are alcoholates derived from the residue R according to the above definition, especially the corresponding sodium and potassium alcohols. The use of such alcoholates is preferred from the corresponding esters immediately obtained, while when using alkali metal and alkaline earth metal hydroxides, the first salts of these bases are obtained with the formed 2-(2',2'-dihalovinyl)-cyclopropanecarboxylic acids. However, these can also be done in a simple and per se known manner, e.g. transfer into the corresponding acid chloride and reaction with an alcohol derived from the residue R, is transferred into ether.

The transfer of a 2-(2','2',21-trihaloethyl)-4-halocyclobutan-1-one of formula I into a 2-(2',2'-dihalovinyl)-cyclopropanecarboxylic acid derivative of formula VIII is carried out depending on the base used, suitably in aqueous, aqueous-organic or organic media. When an alkali metal or alkaline earth metal carbonate is used as a base, reaction is carried out in an aqueous or aqueous-organic medium. The reaction in the presence of alkali metals and alkaline earth metal hydroxides and alkali metal hydrogen carbonates is also advantageously carried out in an aqueous or aqueous-organic medium. Thereby, after acidifying the reaction mixture, e.g.

by addition of concentrated hydrochloric acid, the free 2-(2',2'-dihalogenovinyl)-cyclopropanecarboxylic acids of formula VIII

(R = H).

Suitable solvents for the reaction of 2-(2',2',2'-trihalomethyl)-4-halocyclobutan-1-ones of formula I in 2-(2',2<1->dihalovinyl)-cyclopropanecarboxylic acid derivatives j with formula VIII in aqueous-organic or organic medium is. suitable alcohols, for example those with 1 to 6 carbon atoms such as benzyl alcohol, aliphatic or cyclic ethers such as diethyl ether, di-n-propyl ether, di-isopropyl ether, tetrahydrofuran and dioxane as well as aliphatic, cycloaliphatic or aromatic hydrocarbons such as n-pentane, n-hexane , cyclohexane, benzene, toluene and xylenes.

The conversion of 2-(2',2',2'-trihaloethyl)-4-halocyclobutan-1-ones of formula I to 2-(2',2<1->dihalovinyl)-cyclopropanecarboxylic acid derivatives of formula VIII is carried out in generality at the selected reaction medium's boiling point. Reaction temperatures between 40 and 120°C are particularly suitable.

In the transfer of 2-(2<1>,2<1>,2<1->trihaloethyl)-4-halogeno-cyclobutan-1-ones of formula I in 2-(2',2<1->dihalovinyl )-cyclopropanecarboxylic acid derivatives of formula VIII appear

intermediate the corresponding 2-(2<1>,2',2<1->trihaloethyl)-cyclopropane-carboxylic acid derivatives of formula X

where R, R1, R2 and X have the above meaning as intermediates. These products can be collected when the reaction temperature is kept below 40°C and/or applied

a deficit of bases. These intermediate products pass above 40°C upon addition of further base during HX cleavage into the corresponding 2-(22'-dihalogenovinyl)-cyclopropanecarboxylic acid derivatives of formula VIII..

2-(2',2<1>,2'-trihaloethyl)-cyclopropanecarboxylic acid derivatives of formula X can also by irradiation with UV light, optionally

during the addition of common sensitizers (e.g.

. ketones, such as acetone, cyclohexanone, benzophenone, acetophenone and higher alkylaryl ketones, thioxanthone, etc.) in the presence of reagents containing hydroxyl groups which simultaneously

can serve as a solvent, is produced photochemically from

2-(2', 2',2'-trihaloethyl)-4-halocyclobutan-1-ones of formula I. Reagents containing hydroxyl groups are e.g. alkanols such as methanol, ethanol etc. and above all water.

The method according to the invention is explained in more detail by the following examples.

EXAMPLE 1

a) Production of 2, 4, 4, 4-tetrachlorobutyric chloride

452.5 g (5 mol) acrylic acid chloride (technical grade),

1.5 liters of carbon tetrachloride, 1.5 liters of acetonitrile and 30 g of cuprous (I) chloride are kept for 24 hours at 115°C. The reaction mixture is clearly filtered and evaporated under a water jet vacuum. The remainder is distilled. You get 922 g (76% of theory) of 2,4,4,4-tetrachlorobutyric acid chloride, boiling point 78 - 80°C/11 mm Hg.

IR spectrum (CHCl 3 ) in cm"<1>: 1780 (C=0).

NMR spectrum (100 MHz, CDCl 3 ) in ppm: 3.16-3.94 (m, 2H, CH 2 ); 4.84-4.96 (m, 1H, CF.).

2,4,4,4-tetrachlorobutyric acid chloride can also be prepared as follows: 90.5 g (1 mol) acrylic acid chloride, 0.5 liter carbon tetrachloride, 0.2 liter butyronitrile and 3 g copper powder are heated for 20 hours at 115°C. The reaction mixture is filtered and evaporated and the residue is distilled. You get 167.8 (69%

of theoretical) 2,4,4,4-tetrachlorobutyric acid chloride; boiling point 80 - 81°C/12 mm Hg. The spectroscopic data is identical to that for the 2,4,4,4-tetrachlorobutyric acid chloride prepared according to the first paragraph.

If the copper powder is replaced with cupric (I) chloride and the butyronitrile with 3-methoxypropionitrile under otherwise the same working method, 2,4,4,4-tetrachlorobutyric acid chloride is obtained in a yield of 71% of theoretical.

226 g (1 mole) of 2,4,4,4-tetrachlorobutyric acid [prepared according to Israeli patent 18771 =.CA, (53 , 13089e (1965)], 600 g of thionyl chloride and 1 ml of N,N-dimethylformamide are heated for 2 hours at 50 °C and 2 hours at 75°C. After evaporation of the excess thionyl chloride, the residue is distilled. 227.6 g (93% of theory) of 2,4,4,4-tetrachlorobutyric acid chloride, boiling I , are obtained.

point 90 - 90°C/15 mm Hg. -145.9 g (1.5 mol) 1,1-dichloroethylene. 147.4 g (1 mol) of dichloroacetyl chloride, 200 ml of acetonitrile1 and 3 g of cupric (I) chloride are heated for 8 hours at 130°C. The reaction mixture is evaporated and the residue fractionally distilled. 2,4,4,4-tetrachlorobutyric acid chloride is obtained as a colorless liquid, boiling point 78 - 80°C/11 mg Hg. The spectroscopic data for the obtained substance are identical to those for the 2,4,4,4-tetrachlorobutyric acid chloride prepared according to the first paragraph.

b) Preparation of 2-chloro-2-(2',2',2'-trichloroethyl)-3,3-dimethylcyclobutan-1-one

In an autoclave, 280 g of isobutylene are pressed into 122 g (0.5 mol) of 2,4,4,4-tetrachlorobutyric acid chloride in 600 ml of cyclohexane. At 65°C, a solution of 51 g (0.5 mol) of triethylamine in 500 µl of cyclohexane is pumped into this over the course of 4 hours. The reaction mixture is then kept for a further 3 hours at 65°C. The precipitated hydrochloride of triethylamine is filtered off.

79.4 g of 2-chloro-2-(2',2•,2<1->trichloroethyl)-2,2-dimethyl-ocyclobutan-1-one are obtained with a melting point of 75 - 76 C (60% of theoretically) .

IR spectrum (CHCl 3 ) in cm 1 : 1805 (=0).

<1>H-NMR spectrum (100 MHz, CDCl 3 ) in ppm: 1.42 and 1.45 (each ls, 6H, each 1 CH 3 ); 2.91-3.28 (m, 2H, CH2); 3.37-3.76 (m, 2H, CH 2 ).

13 C-NMR spectrum (CDC13( in ppm: 196 (s, CO); 95.3 (s, CH3); 80.8 (s, C-2); 57.0 (t, CH2); 56, 4 (t, CH2); 37.9 (s, C-3); 25.1 (q, CH3); 28.8 (q, CH3).

Elemether analysis for CgH^gCl^O (mol weight 263.98):

c) Preparation of 2-(2',2',2'-trichloroethyl)-3,3-dimethyl-4-chiorcyclobutan-r-one

132 g. (0.5 mol) of what was obtained. 2-chloro-2-(2 1 , 2 ', 2 '-trichloroethyl)-3,3-dimethylcyclobutan-1-one is dissolved in 700 ml of toluene, mixed with 1 ml of triethylamine and boiled under reflux. After a reaction time of 13 hours, 1 ml of triethylamine is added again and the whole is boiled for a further 7 hours. After cooling, the reaction mixture is washed first with dilute hydrochloric acid and then with water, dried and evaporated; The solidified TLC uniform residue (124 g; 94% of theory) is crystallized from n-hexane. 105.8 g of 2-(2',2',2'-trichloroethyl)-3,3-dimethyl-4-chlorocyclobutane-1-

pn, melting point 56 - 57°C.

IR spectrum (CHCl 3 ) in cm"<1>: 1800 (C=0).

<1>H-NMR spectrum (100 MHz,.CDCl3) in ppm: 4.77 (d, J=2 Hz, 1H,

H at C-4); 3.46 (m, 1H, H at C-2); 2.73-3.26 (m, 2H, CH2); 2.63 (s, 3H, CH3); 1.14 (s, 3H, CH3).

<13>C-NMR spectrum (CDCl3) in ppm: 197.0 (s, CO); 97.8 (p, CC13);

69.4 (d, C-4); 60.6 (d, C-2); 49.5 (t, CH 2 -CC 3 );

36.8 (p, C-3); 27-4 (q, CH 3 ); 18.6 (q, CH 3 ).

Elemental analysis for CqH^qCI^O (mol weight 263.98):

The above compound can also be prepared as follows: 2.64 g (0.01 mol) of 2-chloro-2-(2',2<1>,2'-trichloroethyl)-3,3-dimethylcyclobutanone is stirred for 6.5 hours with 220 mg (0.0008 mol) of tetra-n-butylammonium chloride at 124°C. The cooled mixture is boiled with hot n-hexane and filtered clear.

On cooling, 2.19 g (83% of theoretical) 2-(2',2',2'^trichloroethyl)-3,3-dimethyl-4-chlorocyclobutanone are separated, melting point 53-56°C.

j

d) Preparation of 2-(2'2'-dichlorovinyl)-3,3-dimethyl-cyclopropane-r-carboxylic acid

13.2 g (0.05 mol) of 2-(2',2',2'-trichloroethyl)-3,3-dimethyl-4-chlorocyclobutan-1-one are mixed in 150 ml of 10% caustic soda and stirred vigorously. After 5 minutes, a clear solution has formed which is heated for 1 hour at 100°C (bath temperature). The reaction solution is washed with diethyl ether, acidified under cooling with concentrated hydrochloric acid and extracted with diethyl ether. The ether phase is washed with water, dried over magnesium sulphate and evaporated. According to the NMR spectrum, the solid residue (10.35 g) consists of 80% by weight of cis-

and 20% by weight of trans-2-(2',2'-dichlorovinyl)-3,3-dimethylcyclopropane-1-carboxylic acid. The crystallization from n-hexane gives

a cis-acid, melting point 85 87°C.

IR spectrum (CHCl 3 ) in cm"<1>: .1 710 (CO)', 1 625 (C=C).

NMR spectrum (100 MHz, CDCl 3 /D 2 O) in ppm: 1.30 (s, 6H, 2

times CH3); 1.85 (d, J=8.5 Hz, 1H, HC-1); 2.02-2.19 (m, 1H, HC-2); 6.17 (d, J = 8 Hz, 1H, CH=CCl 2 ).

EXAMPLE 2

421 g of propylene, 244 g (1 mol) of 2,4,4,4-tetrachlorobutyric acid chloride and 1.25 liters of cyclohexane are placed in a 6.3 liter autoclave. At 50°C, a solution of 101 g (1 mol) of triethylamine in 1 liter of cyclohexane is pumped into this over the course of 4 hours, and then the reaction mixture is kept for 3 hours at 50°C. The reaction mixture is filtered and the filtrate obtained is washed with dilute hydrochloric acid and then with water, dried over magnesium sulfate and evaporated. The residue is crystallized from n-hexane. 77.2 g of 2-chloro-2-(2',2',2'-trichloroethyl)-3-methyl-cyclobutan-1-one are obtained, melting point 80 - 81 C.

IR spectrum (CHCl 3 ) in cm"<1>: 1785 (CO).

?-NMR spectrum (100 MHz, CDCl 3 ) in ppm: 3.28 - 3.73 (m, 3H), ;

2.65-2.95 (m, 2H); 1.43 (d, J=6.5 Hz, 3H, CH-j).

<13>C-NMR spectrum (CDCl3) in ppm: 196.5 (s, CO); 95.1 (s,

CC13); 77.0 (p, C-2); 55.3 (t, CH 2 -CC 3 ); 50.9 (t, C-4); 30.1 (d, C-3); 15.0 (q, CH 3 ). 50 g (0.2 mol) of the obtained 2-chloro-2-(21,2',2'-trichloroethyl)-3-methylcyclobutan-1-one in 500 ml of toluene are mixed with 1 ml of triethylamine and stirred for 10 hours at 120°C bath temperature. The reaction mixture is clearly filtered after cooling and washed, first with dilute hydrochloric acid and then with water, boiled briefly with activated charcoal, filtered again and evaporated. The distillation of the residue gives 38.7 g (77% of theoretical yield) 2-(2',2',2'-trichloroethyl)-3-methyl-4-chlorocyclobutan-1-one, melting point 130 - 131°C /12 mm Hg.

IR spectrum (CHCl 3 ) in cm"<1>): 1005 (CO).

NMR spectrum (10 0 Hz, CDCl 3 ) in ppm: 1.20 (d, J=7 Hz, 0.6H,

CH3); 1.46 (d, J=7 Hz, 0.45 H, CH 3 ); 1.66 (d, J=6.5 Hz, 1.95 H, CH 3 ); 2.1 - 3.5 (m, 4H)! 4.55 (dd, J=8 and 2 Hz, 0.65 H, CH); 5.00 (dd, J=9 and 2.5 Hz, 0.15 H, CH) ; 5.1.5 (dd, J=9 and 1.5 Hz, 0.2 H, CH) .

According to the NMR spectrum and gas chromatogram, the compound consists of 3 stereoisomers in the weight ratio 13:4:3.

10.5 g of the obtained 2-(21,21,2*-trichloroethyl)-3-methyl-4-chlorocyclobutan-1-one is stirred with 100 ml of 10% caustic soda for 50 minutes. The resulting solution is then heated for 1 hour at 100°C. The reaction mixture is then washed with diethyl ether and carefully acidified with concentrated hydrochloric acid. Then extract with diethyl ether. The ether extract is washed with water, dried over magnesium sulphate and evaporated. 2-(2',2'-dichlorovinyl)-3-methylcyclopropane-1-carboxylic acid is obtained, melting point 75 - 70°C (recrystallized from n-hexane).

IR spectrum (KBr) in cm"<1>: 1 605 (C=0) , 1 625 (C=0) ..

NMR spectrum (100 MHz, CDCl.3/D2O) in ppm: 1.25 (d, J=5.5 Hz,

3H, CH 3 ): 1.54-2.10 (m, 3H); 3.96 (d,.J=0 Hz, 1H, in CH=CC12).

EXAMPLE 3

A solution of 25.3 g (0.25 mol) of triethylamine in 50 ml of n-hexane is added dropwise over the course of 7 hours with stirring to a solution of 25 g (0.37 mol) of methylenecyclobutane and 61.1 g (0.25 mol) of 2,4,4,4-tetrachlorobutyric acid chloride in <200 ml of n-hexane maintained under reflux. After stirring for a further 2 hours under reflux, the still warm reaction mixture is freed by filtration from the ammonium salt formed. The filtrate is evaporated to approx. 1/3 of the volume. On cooling, 1-chloro-1-(2',21,21-trichloroethyl)-sp^Oj|: 13 is separated. 3 ] heptan-2-one of formula

in crystalline form, melting point 93 - 94°C.

IR spectrum (CC14) in cm<-1>: 1790 (C=0).

NMR spectrum (100 MHz, CDCl 3 ) in ppm: 1.70-2.80 (m, 6H);

3.15-3.60 (m, 4H).

A solution of 27.6 g (0.1 mol) of the obtained 1-chloro-1-(2<1>,2',2'-trichloroethyl)sior[3.3]heptan-2-one in 100 ml of toluene is boiled together with 0.93 g (5 mmol) of tributylamine for 9 hours under reflux. The reaction mixture is then evaporated, and the residue is distilled under vacuum. One obtains 1-chloro-3-(2 ' , 2 ' , 2 ' -trichloroethyl) spiro [3.3] heptan-2-one with the formula in the form of a light yellowish oil, melting point 85 - 90°C/

0.005 Torr; N^°■= 1.5242.

IR spectrum (film).in cm<_1>: 1,795 (C=0).

NMR spectrum (100 MHz, CDCl 3 ) in ppm: 1.80-3.85 (m, 9H);

4.68, 4.93 (each one d, together 1H).

11.0 g (40 mmol) of the obtained 1-chloro-3-(2',2',2'-trichloroethyl)spiro[3;3]heptan-2-one is stirred together with 95 ml (approx.

240 mmol) 10% sodium hydroxide solution for 6 hours at 95°C. After cooling, wash with several portions of diethyl ether, acidify with sulfuric acid and extract with diethyl ether. The ether extracts are evaporated after drying over sodium sulphate. By filtering the residue over 10 times the amount by weight of silica gel

(eluent n-hexane/diethyl ether in volume ratio 1:1)

a small amount of strongly polar contaminants is removed. Subsequent evaporation of the filtrate yields 2-(2 1 , 2 '-dichlorovinyl)-spiro [ 2 . 3 ] hexane-1-carboxylic acid" with formula

as 2:1 cis/trans mixture, mp 121-28°C.

IR spectrum (CC14) in cm"<1>: 1705 (C=0).

NMR spectrum (100 MHz, CDCl 3 ) in ppm: 1.60-2.60 (m, 8H;

5.34, 5.97 (each d, total 1H); 11.80-11.50 (width s, 1H).

EXAMPLE 4

280 g of isobutylene is pressed into an autoclave to 122 g (0.5 mol) of 2,4,4,4-tetrachlorobutyric acid chloride in 600 ml of cyclohexane. At 65°C, 51 g (0.5 mol) of triethylamine are pumped into 500 ml of cyclohexane over the course of 4 hours. Then the reaction mixture is kept

o

.3 hours at 6 5 C and then heated for 18 hours at

125°C. Here, 2.0 g of triethylamine in 50 ml of cyclohexane are pumped in every three hours. The reaction mixture is poured onto ice, acidified with hydrochloric acid and extracted with cyclohexane. The evaporated extract is filtered in toluene/cyclohexane (1:1 volume mixture) over 1 kg of silica gel to remove highly polar impurities. The filtrate is evaporated and the residue is crystallized from n-hexane. 31.8 g of 2-(2',2',2'-trichloroethyl)-3,3-dimethyl-4-chlorocyclobutan-1-one are obtained, melting point 56 - 57°C.

EXAMPLE 5

a) 26.1 g (99 mol) of 2-(2',2',2<1->trichloroethyl)-3,3-dimethyl-4-chlorocyclobutanone are placed under stirring at 11°C to 260

ml of a 10% caustic soda. Within 2.4 hours the temperature rises to 28°C and then falls within 2 further hours to 20°C. The reaction mixture is then diluted with 200 ml of water, washed with diethyl ether, acidified strongly with concentrated hydrochloric acid and extracted with diethyl ether. The extract is washed with water, dried over sodium sulphate and evaporated. You get 24.3 g (100% of theoretical yield) of one pale yellow residue (melting point 80 - 81 o C) which exclusively consists of cis- and trans-2-(2',2<1>, 2'-trichloroethyl)-3,3-dimethylcyclopropanoic acid. By fractional crystallization or by. column chromatography, the mixture can be split into the pure cis- and trans-compounds.

NMR spectrum (100 MHz, CDCl 3 /D 2 O) in ppm: 2.7-5-3.33 (m, 2H);

1.50-1.97 (m, 2H); 1.32 (s, 2xCH 3 cis ); 1.27 and 1.38

(2xs, 2xCH3trans).

b) 8.0 (30.3 mmol) 2-(2',2',2'-trichloroethyl)-3,3-dimethyl-4-chlorocyclobutanone is irradiated in 400 ml acetone and 100 ml

water through Pyrexglass with a Philipps HPK 125W lamp until the starting material can no longer be detected chromatographically. The reaction mixture is evaporated and the residue as indicated under a) to acid. You get 6.95 g (93% of theoretical yield)

of a cis/trans mixture of 2-(2',2',2'-trichloroethyl)-3,3-

dimethylcyclopropanecarboxylic acid whose spectroscopic data are identical to the mixture obtained according to a).

c) 24.55 g (0.1 mol) of 2-(2',2•,2'-trichloroethyl)-3,3-dimethyl-cyclopropanecarboxylic acid is suspended in .350 ml of 10% caustic soda

and stirred for 4.5 hours at 100°C bath temperature. The reaction solution is washed with diethyl ether, acidified with hydrochloric acid and extracted with chloroform. The extract is washed with water, dried over sodium sulphate and evaporated. After crystallization from n-hexane, 17.55 g (84% of theoretical yield) of colorless 2-(2',2<1->dichlorovinyl)-3,3-dimethylcyclopropanecarboxylic acid are obtained.

EXAMPLE 6

14 5 (0.5 mol) 2-bromo-4, 4, 4-trichlorobutyric acid chloride, 280 g

(5 mol) of isobutylene and 600 ml of cyclohexane are placed in an autoclave. At 65°C, 51 g (0.5 mol) of triethylamine in 500 ml of cyclohexane are pumped into this over the course of 4 hours. It is then stirred for a further 3 hours at this temperature. The reaction mixture is filtered. The filtrate is evaporated and the residue is crystallized from n-hexane. 74.5 g (48% of theoretical yield) of 2-bromo-2-(2',2',2'-trichloroethyl)-3,3-dimethylcyclobutanone are obtained as yellowish-beige powder, melting point 46 - 49°C.

IR spectrum (CHCl 3 ) in cm"<1>: 1885 (CO).

<1>H-NMR spectrum (100 MHz, pyridine-d^) in p<p>m: 3.7 9 (AB,2H,

CH 2 ); 3.10 (AB, 2H, CH2); 1.37 and 1.4 2 (each ls, total 6H, each CH3).

13 C-NMR spectrum (CDCl 3 ) in ppm: 196.8 (CO); 95.6 (CCl 3 );

74.8 (C-2); 56.5 and 56.3 (each CH 2 ); 38.0 (C-3);

27.4 and 24.7 (each CH3).

20 g (0.065 mol) of 2-bromo-2-(2',2*,2'-trichloroethyl)-3,3-dimethylcyclobutanone and 5 g of tetrabutylammonium bromide are stirred

30 minutes at 80°C and 10 minutes at 100°C. It

the solidified melt is chromatographed over silica gel (elution with toluene/cyclohexane 1:1). ,'melting point 56°C.

<1>NMR spectrum (100 MHz, CDCl3) in ppm: 4.99 (d, J=2Hz, 1H,

H to C-4); 3.58 (X part of ABX, split additively with J=2Hz, 1H, H to C-2); 3.05 (AB part of ABX, 2H, CH2); 1.22 and 2.67 (each ls, each 3H, each CH2).

<13>C-NMR spectrum (CDCl3) in ppm: 196.7 (s, CO); 97.7 (p, CC13);

60.7 (d, C-2); 59.8 (d, C-4); 50.0 (t, CH2"CCl3);

36.4 (p, C-3); 27.6 (q, CH 3 ); 21.0 (q, CH 3 ).

3.1 g (10.6 mmol) of 2-(2',2',2'-trichloroethyl)-3,3-dimethyl-4-bromocyclobutanone are mixed with a solution of 3.2 g of NaOH in 70 . ml of water and stir for 2 hours. Then stir for a further 3 hours at 100°C. The reaction mixture is washed with diethyl ether and acidified with dilute hydrochloric acid. This aqueous phase is extracted with diethyl ether. The extract is washed with water, dried over magnesium sulphate and evaporated. The residue is crystallized from n-hexane. 2.55 g of cis-2-(2',2'-dichlorovinyl)-3,3-dimethylcyclopropanecarboxylic acid are obtained; melting point 86°C.

IR spectrum (CHC13) in cm"<1>: 1710 (CO), 1625. (C=C)..

NMR spectrum (100 MHz, CDCl 3 /D 2 O) in ppm: 1.30 (s, 6H, 2x CH 3 ); 1.85 (d, J=8.5 Hz, 1H, HC-1); 2.02-2.19 (m,

1H, HC-2); 6.17 (d, J=8 Hz, 1H, CH=Cl2).

EXAMPLE 7

90.5 g (1 mol) acrylic acid chloride, 364.8 g (1.1 mol) tetrabromomethane, 200 ml acetonitrile and 5.0 g cuprous (I) chloride

.heated for 6 hours, at 115°C. After cooling, distill<1>

the reaction mixture directly. 136.6 g (33% theoretical yield) of 2,4,4,4-tetrabromobutyric acid chloride is obtained, boiling

point 135 - 140°C 12 mm Hg.

350 ml of cyclohexane is saturated with isobutylene at room temperature (20 - 25°C). 42.2 g (0.1 mol) of 2,4,4,4-tetrabromobutyric acid chloride are dissolved in it. Then 10.1 g (0.1 mol) of triethylamine in 50 ml of cyclohexane are added drop by drop at room temperature during 2 hours with stirring and a weak stream of isobutylene. The resulting reaction mixture is stirred for 3 hours and then mixed with water. The organic layer is separated, washed with water, dried over magnesium sulphate and concentrated. The residue is filtered over silica gel (eluent cyclohexane/toluene 1:1 volume mixture). The filtrate is evaporated. The residue is crystallized from n-hexane.

This gives 2-bromo-2-(2<1>,2',2<1->tribromethyl)-3,3-dimethylcyclobutanone, melting point 61 - 63°C.

IR spectrum (CHCl'3) in cm<_1>:.1780 (CO).

<1>H-NMR spectrum (100 MHz, CDCl3) in ppm:. 3.97 (AB, 2H, CH2)

3.13 (AB, 2H, CH2); 1.51 and 1.61 (each 1s, each 3H, each CH3).

13 C-NMR spectrum (CDCl 3 ) in pm: 196.7 (CO); 76.8 (C-2); 6 0.0 and 56.6 (each CH 2 ); 38.1 (C-3); 31.7 (CB'r3);

27.7 and 25.0 (each CH3).

9.6 g (21.8 mmol) of 2-bromo-2-(2',21,2'-tribromomethyl)-3,3-dimethylcyclobutanone are stirred with 2.0 g of tetrabutylammonium bromide for 30 minutes at 90°C . The cooled melt is chromatographed over silica gel (elution with toluene/cyclohexane 1:1). 2-(2<1>,2',2'-tribromomethyl)-3,3-dimethyl-4-bromocyclobutanone is obtained as a slowly crystallizing oil which is recrystallized from diethyl ether/n-hexane, melting point 9o-93°C.

IR spectrum (CHCl 3 ) in cm"<1>: 1795 (CO).

<1>H-NMR spectrum (100 MHz, CDCl 3 ) in ppm: 4.96 (d, J=2Hz, 1H, in

H to (C-4); 3.12-3.67 (ABX, whereby the X moiety is split with the addition of J=2Hz, 3H, CH2~CH);

1.18 and 1.67 (each ls, each 3h, each CH3).

<13>C-NMR spectrum (CDCl3): 196.4 (s, CO); 63.2 (d, C-2);

59.9 (d, C-4); 54.6 (t, CH 2 ); 38.4 (s, CBr 3 );

36.4 (p, C-3); 27.8 and 21.3 (each q, each CH3).

700 mg (1.56 mmol) of 2-(2',2<1>,2'-tribromethyl)-3,3-dimethyl-4-bromocyclobutanone are stirred with a solution of 190 mg of NaOH in 5 ml of water to which 0 .5 ml of dioxane at room temperature for 2 hours. Then stir for 1 hour at 80°C. The clear solution is worked up as usual to acid. 410 mg (88% of theoretical yield) of cis-2-(2',2'-dibromovinyl)-3,3-dimethyl-cyclopropanecarboxylic acid are obtained.

IR spectrum (CHCl 3 ) in cm -1 : 1695 (CO).

NMR spectrum (100 MHz, CDCl 3 /D 2 O) in npm: 6.7 0

6d, J=8Hz, 1H, CH-CBr2); 1.82-2.14 (m, 2H);

1.30 and 1.33 (each ls, total 6H, each CHj).

EXAMPLE 8

To a solution of 14 g (0.17 mol) of ethylenecyclopentane and 26.4 g (0.1 mol) of 2,4,4,4-tetrachlorobutyric acid chloride in 220

10.1 g (0.1 mol) of triethylamine in 100 ml of cyclohexane are added dropwise over the course of 2 hours while stirring at 65°C. The mixture is then stirred for 3 hours at this temperature. The reaction mixture is washed with dilute hydrochloric acid, then with water, dried over magnesium sulfate and concentrated. The residue is crystallized from n-hexane. 16.6 g of 1-chloro-1-(2',2',2'-trichloroethyl)spiro[3.4]octan-1-one with formula

IR spectrum (CHCl 3 ) in cm"<1>: 1775 (CO).

NMR spectrum (100 MHz, CDCl 3 ) in ppm: 1.60-2.30 (m, 8H);

3.00 (AB, 2H, CH0); 3.60 (AB, 2H, CH2).

12.0 g (0.041 mol) of 1-chloro-1-(2',2',2'-trichloroethyl)spiro [3.4]octan-2-one is stirred with 3.6 g of tetrabutylammonium chloride at 125°C bath temperature. After 1.5 hours, the reaction mixture is chromatographed on silica gel (elution with toluene/cyclohexane 1:1). In this way, you get 9.7 g (81% of

theoretical yield) 1-chloro-3-(2',2',2'-trichloroethyl)spiro

[3.4]octan-2-one of formula

1 form of a colorless oil.

IR spectrum (CHCl3) in cm"<1>: 1800 (CO).

NMR spectrum (100 MHz, CDCl3) in ppm: 4.87 (d, J=2Hz, 1H,

CHC1); 3.70 (the X part of ABX, is split with the addition of j=2Hz, 1H, CH); 2.73-3.29 (AB part of ABX, 2H, CH2); 1.45-2.23 (m, 8H.

4.83 g (16.6 mmol) of 1-chloro-3-(2',2',2'-trichloroethyl)spiro[3 in 4]octan-2-one is added to a solution of 2.0 g of NaOH in 40 ml of water and 3 ml of dioxane and stirred at room temperature

2 hours and then 3 hours at 100°C. The reaction mixture

I is washed with diethyl ether and acidified with dilute hydrochloric acid.

The acidic solution is extracted with diethyl ether. The extracts are washed with water, dried over magnesium sulphate and evaporated. The residue is crystallized from n-hexane. 3.3 g of 2-(2',2'-dichlorovinyl)spiro[2.4]heptane-1-carboxylic acid with the formula is obtained

as white powder, melting point 90 - 105°C.

IR spectrum (CHCl 3 ) in cm"<1>; 1705 (CO), 1620 (C=C).

NMR spectrum (100 MHz, CDCly^O) in ppm: 6.15 (d, J=9Hz,

0.8H, CH=CCl3cis); 5.51 (d, J=9Hz, 0.2H, CH=CCl2trans); 2.00-2.40 (m, 211) ; 1.60-1.95 (m, 8H).

EXAMPLE 9

In a 2.5 liter autoclave, 33.6 g (0.62 mol) of methylenecyclopropane and 152 g (0.62 mol) of 2,4,4,4-tetrachlorobutyric acid chloride are placed in 6 20 ml of n-pentane. At 60°C, 62.8 g (0.62 mol) of triethylamine in 120 ml of n-pentane are pumped in over the course of 6 hours and the reaction mixture is then kept at 60°C for 6 hours. The reaction mixture is filtered, evaporated and the residue is distilled in vacuo. The fraction with the boiling range 45 - 80°C/ 0.09 Torr is then chromatographed on 250 g of silica gel with hexane/

0 - 50 wt% toluene. The pure fractions are evaporated and the remainder distilled. One obtains 1-chloro-(2',2<1>,2'-trichloroethyl)-spiro[3.2]hexane-2-pn with the formula

with boiling point 7 0. - 71°C/0.08 Torr.;

IR spectrum .(CHCl-j) in ein"1: 1776 (CO).

.sup.-NMR spectrum (100 MHz, CDCl 3 ) in ppm: 0.8-1.8 (m, 4H);

2.6-3.8 (m, 4H).

A solution of 11.0 g (42 mmol) of 1-chloro-1-(2 1 , 2 ' , 2 1 -tri-?chloroethyl)spiro[3.2]hexan-1-one and 1.17 g (6.3 mmol) of tributylamine in 15 ml of toluene is boiled for 5 hours under reflux. After cooling, the reaction mixture is diluted with n-pentane. Wash with 2N sulfuric acid and then with saturated sodium chloride solution, dry over sodium sulphate and evaporate. The remainder is distilled in vacuum. One obtains 1-chloro-3-(2',21,21-trichloroethyl)spiro[3.2]hexan-2-one with the formula

with boiling point 60°C/0.01 Torr.

IR spectrum (CC14) in cm"<1>: 1780 (CO).

NMR spectrum (100 MHz, CDCl 3 ) in ppm: 0.8-1.7 (m, 4H).;

2.6-4.2 (m, 3H) 4.75, 5.15 (each one d; together 1H) .

7.1 g (27 mmol) 1-chloro-3-(2<1>,2',2<1->trichloroethyl)spiro

[3.2]Hexan-2-one is heated together with 54 ml (approx. 135

mmol) 10% NaOH for 2 hours under reflux. After cooling, wash with several portions of diethyl ether, acidify with sulfuric acid and extract with diethyl ether. The ether extracts are evaporated after drying over sodium sulphate. By filtering on silica gel (eluent diethyl ether) a small amount of highly polar contaminants is removed. After evaporation of the filtrate, 2-(2',2'-dichlorovinyl)spiro t2.2]penta-1-carboxylic acid with the formula

as approx. 3.1 cis/trans mixture, melting point 77-78°C.

IR spectrum (CC14) in cm<-1>:. 1675' (CO).

NMR spectrum (100 MHz, CDCl 3 ) in ppm: 0.8-2.85 (m, 6H);

5.56 and 6.11 (each one d, together 1H); 10.8 (width s, 1H).

The following examples describe the preparation of some insecticidally active compounds.

EXAMPLE 10

Preparation of the m-phenoxybenzyl ester of 2-(2',2'-dichlorovihyl)-3,3-dimethylcyclopropane-1-carboxylic acid

a) 4.18 g (0.02 mol) of 2-(2',2-dichlorovinyl)-3,3-dimethyl-cyclopropane-1-carboxylic acid is heated for 3 hours with 20

ml of thionyl chloride at 70°C. The excess thionyl chloride is then evaporated, the residue is taken up in 100 ml of benzene and evaporated again. The residue [2-(2',2'-dichlorovinyl)-3,3-dimethylcyclopropanecarbonic acid chloride] is mixed with a solution of 4.0 g (0.02 mol) of m-phenoxybenzyl alcohol in 40 ml of absolute benzene and heated to 4 0°C To this, 2.2 g (0.022 mol) of triethylamine in 10 ml of absolute benzene are added dropwise over the course of 1 hour and the reaction mixture is stirred for one hour at this temperature. The reaction mixture is washed with dilute hydrochloric acid, dried over magnesium sulfate and evaporated. The residue is chromatographed with diethyl ether/n-hexane as eluent (1:4 volume mixture) over silica gel. The m-phenoxybenzyl ester of 2-(2',2'-dichlorovinyl)-3,3-dimethylcyclopropane-1-carboxylic acid is obtained with a refractive index of n^°<=>1.5628.

b) Dissolve 5.28 g (0.02 mol) of 2-(2',2',2'-trichloroethyl)-3,3-dimethyl-4-chlorocyclobutan-1-one in 25 ml of absolute dimethoxyethane, drop into a solution of 4.0 g (0.02 mol) m-phenoxybenzyl alcohol 0.5 g (0.021 mol) NaH and 40 ml absolute dimethoxyethane. It is then stirred for 1 hour at 45°C, the reaction mixture is then mixed with 2.25 g (0.02 mol) of potassium tert-butylate, and boiled for 3 hours under reflux. After addition to water, acidify with dilute hydrochloric acid and extract with benzene. The evaporated extract is chromatographed over silica gel with diethyl ether/n-hexane as eluent (1:4 volume mixture). The m-phenoxybenzyl ester of 2-(2',2'-dichlorovinyl)-3,3-dimethylcyclopropane-1-carboxylic acid is obtained as a viscous oil, which has the properties of the compound obtained according to a). EXAMPLE 11 cis-2-(2',2'-dichlorovinyl)-3,3-dimethylcyclorooanecarbonic acid-ft-cyano-m-phenoxybenzyl ester a) 10 g (0.047 mol) cis-2-(2•,2',2< 1->dichlorovinyl)-3,3-dimethylcyclopropanecarboxylic acid is stirred in 100 ml of benzene with 12.1 ml (0.141 mol) of oxalyl chloride for 24 hours at room temperature. After evaporation of the reaction solution, the brown liquid is distilled under reduced pressure. You get 9.1 g of a clear liquid, boiling point 50°C/0.04 mm Hg. 3.0 g of this clear liquid is dissolved in 30 ml of toluene and mixed with 2 ml of pyridine. At room temperature, 2.9 g of α-cyano-m-phenoxybenzyl alcohol in 20 ml of toluene are added dropwise, and the reaction mixture. The mixture is then stirred for a further 16 hours at room temperature. The reaction mixture is first washed with water, then with saturated sodium bicarbonate solution and finally with sodium bicarbonate solution, dried over magnesium sulfate and evaporated. The residue is chromatographed over silica gel (elution with diethyl ether/n-hexane 1:2). Pure cis-2-(2',2'-dichlorovinyl)-3,3-dimethyl-cyclopropanecarboxylic acid-a-cyano-m-phenoxy-benzyl ester is obtained as a diastereoisomer mixture. NMR spectrum (60 MHz, CDCl 3 ) in ppm: 1.20-1.43 (m, 6H, CH 3 ); 1.67-2.35 (m, 2H, 2x CH); 6.25 (d, J=9Hz, .1H, CH-CCl 2 ), 6.40 and 6.45 (each ls, each 0.5H, CH-CN); 6.98-7.65 (m.9H).

EXAMPLE 12

To a solution of 22.75 g (0.1 mol) of crude 2-(2',2'-dichlorovinyl)-3,3-dimethylcyclopropanecarboxylic acid chloride [prepared according to Example 1a] and 21.5 g (0.1 mol) 3-phenoxy-α-hydroxyethylbenzene in 250 ml absolute toluene is added dropwise at room temperature 7.8 g (0.1 mol) absolute pyridine. The reaction mixture is stirred for 15 hours at room temperature (20-25°C), waxed with dilute hydrochloric acid, then with water, dried (over sodium sulphate) and evaporated. The residue is chromatographed over silica gel with n-hexane/diethyl ether as eluent (1:1 volume mixture). 2-(2',2'-Dichlorovinyl)-3,3-dimethyl-cyclopropanecarboxylic acid-α-methyl-m-phenoxybenzyl ester is obtained in the form

20

of a colorless oil with nQ= 1.563.

Claims (22)

1. Process for the preparation of 2-(21, 21, 21-trihaloethyl)-4-halocyclobutan-1-ones of formula I where one of the residues R, and R^ means methyl and the other hydrogen or methyl or R^ pg R^ together means an alkylene- group with 2 to 4 carbon atoms and X and Y chlorine or bromine, where, however, when X is bromine, Y must likewise always be bromine, characterized by converting a 2,4,4,4-tetrahalobutyric acid chloride of formula II where X and Y have the meaning given under formula I i presence of an organic base with an olefin of formula III where R^ and R^ have the meaning indicated under formula I. - a 2-(2',2',2'-trihaloethyl)-2-halocyclobutan-1-one of formula IV where , B.^, x and Y has the below formula in the meaning indicated, and then reacts this in the presence of a catalyst in a 2-(2', 2.', 2'-trihaloethyl)-4-halocyclobutane-1- on with formula I. 2. Method according to claim 1, characterized, secondly, by using 2,4,4,4-tetrachlorobutyric acid chloride as 2,4,4,4-tetrahalobutyric acid chloride of formula II. 3. Method according to claim 1, characterized in that one olefin of formula III is used where one of the residues R-^ and R^ • means methyl and the other hydrogen or methyl or R^ and R^ together form an alkylene group with 2 to 3 carbon atoms. 4. Process according to claim 1, characterized in that isobutylene is used as olefin with formula III. 5. Process according to claim 1, characterized in that methylenecyclopropane is used as olefin of formula II. 6. Process according to claim 1, characterized in that the reaction of a 2,4,4,4-tetrahalobutyric acid chloride of formula II with an olefin of formula III is carried out in the presence of pyridine or a trialkylaraine with 1 to 4 carbon atoms in the alkyl group and in the presence of an inert organic solvent. 7. Method according to claim 1, character i- s e-..r t by carrying out the reaction of a 2,4,4,4-tetrahalobutyric acid chloride of formula II with an olefin of formula III in the presence of triethylamine. 8. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2<1>,2',2'-trihaloethyl)-2-halocyclobutan-1-one of formula IV in a 2-(2 ',2',2 <1-> trihalogenethylj-4-halogen-cyclobutan-1-one of formula I uses an inorganic or . organic protonic acid. 9. Process according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2',2'-trihaloethyl)-2-halocyclobutan-1-one of formula IV in a 2-(2', 2',2'-trihaloethyl)-4-halocyclobutan-1-one of formula I uses a hydrogen- halide acid. 10. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',22'-trihaloethyl)-2-halocyclobutan-1-one of formula IV in a 2-(2', 2', 2'-trihaloethyl)-4-halocyclobutan-1-one of formula I uses an organic base. 11. Process according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2<1>,2'-trihalogenethyl)-2-halocyclobutan-1-one of formula IV in a 2-(2 ',22'-trihaloethyl)-4-halo- cyclobutan-1-one of formula I uses an amine of formula where alkyl with 1 to 8 carbon atoms, cycloalkyl with 5 to 6 carbon atoms, benzyl or phenyl and O~ and O_ independently of each other mean hydrogen or alkyl with 1 to 8 carbon atoms. 12. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2',2'-trihaloethyl)-2-halocyclobutan-1-one of formula IV i. a 2-(2' ,2 <1> ,2'-trihaloethyl)-4-halocyclobutane-1-oh of formula I uses salts of protonic acids with ammonia, nitrogen-containing organic bases or quaternary ammonium salts. 13. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2',2'-trihaloethyl)-2-halocyclobutan-one of formula IV in a 2-(2',2 ',2'-trihaloethyl)-4-halocyclobutan-1-one of formula I uses a salt ..a hydrohalide acid with an aliphatic, cycloaliphatic, araliphatic or aromatic primary, secondary or tertiary amine or a heterocyclic nitrogen base. 14.. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2',2'-trihaloethyl)-2-halocyclobutari-1-one of formula IV in a 2-(2' ,2 <1> ,2 <1-> trihaloethyl)-4-halocyclobutan-1-one of formula I uses a salt with formula where M means fluorine, bromine or iodine, especially chlorine, hydrogen, alkyl with 1 to 18 carbon atoms, cyclohexyl, benzyl, phenyl or naphthyl and Q5 , Qg go A? independently hydrogen or alkyl of 1 to 18 carbon atoms or et N-alkyl pyridium halide with 1 to 18 carbo atoms in the alkyl group. 15. Method according to claim 1, characterized in that the rearrangement of a 2-(2', 2', 2'-trihalogenethyl)-2-halocyclobutan-1-one of formula IV is carried out in a 2-(21,2', 2'-trihaloethyl)-4-cyclobutan-1-one of formula I at temperatures between 80 and 130°C. 16. Process according to claim 1, characterized in that the rearrangement of a 2-(2',2',2'-trihaloethyl)-2-halocyclobutan-1-one of formula IV is carried out in a 2-(2',2 ',2'-trihaloethyl)-4-cyclobutan-1-one of formula I in melt at a temperature between 8.0 and 130°C in the presence of a trialkylamine with 1 to 8 carbon atoms in the alkyl groups or a tetraalkylammonium halide with 1 to 18 carbon atoms in the alkyl groups. 17. Method according to claim 1. characterized by carrying out the rearrangement of a 2-(2',2',2'-trihalogenethyl)-4-halocyclobutan-1-one of formula IV in a 2-(2',21,21-trihalogenethyl)-4- halocyclobutah-l-one . with formula I in the presence of an inert solvent. 18. Process according to claim 1, characterized in that the rearrangement of a 2-(2', 2',2'-trihaloethyl)-2-halocyclobutan-1-one of formula IV is carried out in a 2-(2',2' ,2'-trihaloethyl)-4-halocyclobutan-1-one. of formula I in an aliphatic alcohol with 1 to 4 carbon atoms, toluene, xylene, chlorobenzene, dioxane, acetonitrile, 3-methoxypropionitrile, ethylene glycol, diethyl ether or diisopropyl ketone as solvent. 19. 2, 4, 4, 4-tetrahalobutyric acid chlorides of formula II characterized in that X and Y are chlorine or bromine whereby when X is bromine Y must always be bromine. 20. 2-(2',2',2'-trihaloethyl)-2-halocyclobutan-1-ones of formula IV characterized in that one of the residues and R2 means methyl and the other hydrogen or methyl, or R^ and R2 together means the alkylene with 2 to 4 carbon atoms and X and Y chlorine or bromine, where, however, when X is bromine, Y must likewise always be bromine. 21. 2-(2 <1> ,2 <1> ,2 <1-> trihaloethyl)-4-halocyclobutan-1-ones of formula I characterized in that one of the residues R^ and R2 is methyl and the other is hydrogen or methyl or R^ and R2 together are alkylene with 2 to 4 carbon atoms and X and Y are chlorine or bromine, where, however, when X is bromine, Y must likewise always be bromine. 22. Use of 2-(2',2',2'-trihaloethyl)-4-halo- cyclobutan-l-ones of formula I where one of the residues R^ and R2 means methyl and the other hydrogen or methyl or R1 and R2 together the alkylene with 2 to 4 carbon atoms and X and Y are chlorine or bromine, whereby however when X is bromine, Y must likewise always be bromine, for the preparation of compounds of formula VIII where one of the residues R1 and R2 means methyl and the other hydro- gen or methyl or R^ and R« together are alkylene with 2 to 4 carbon atoms, X is chlorine or bromine and R is hydrogen, alkyl of 1 to 4 carbon atoms or a group of formula IX where R^ means oxygen, sulfur or the vinylene group, R^ hydrogen, alkyl of 1 to 4 carbon atoms, benzyl, phenoxy or phenyl mercapto, R,- hydrogen or an alkyl group of 1 to 4 carbon atoms and R^ hydrogen, cyano or ethynyl or, when one of the radicals R-^ and R 2 is methyl and the others hydrogen or methyl, R^ the vinylene group, R^ and R^, hydrogen, also alkyl with 1 to 5 carbon atoms.