NO783313L

NO783313L - PROCEDURE FOR THE PREPARATION OF 2- (2`, 2`, 2`-TRIBROMETHYL) -4-CHLORICYCLOBUTAN-1-ONER

Info

Publication number: NO783313L
Application number: NO783313A
Authority: NO
Inventors: Pierre Martin; Hans Greuter; Eginhard Steiner; Daniel Bellus
Original assignee: Ciba Geigy Ag
Priority date: 1978-09-29
Filing date: 1978-09-29
Publication date: 1980-04-01

Description

Foreliggende oppfinnelse vedrører en forbedring og videre utformning av fremgangsmåten ved fremstilling av 2- (21 2152'-tri-halogenetyl)-4-halogencyklobutan-l-oner ifølge Søkerens norske patentansøkning nr. 78.1112 av 3o.3.1978. The present invention relates to an improvement and further design of the method for the production of 2-(21 2152'-tri-halogenethyl)-4-halocyclobutan-1-ones according to the Applicant's Norwegian patent application no. 78.1112 of 30.3.1978.

Foreliggende oppfinnelse vedrører videre de ved den forbedrete fremgangsmåte fremstillbare, nye 2-(2'^ 2' 2'-trihalogenetyl)-4-halogencyklobutan-l-oner, såvel nye mellomprodukter som kan anvendes for fremstilling derav. The present invention further relates to the new 2-(2'^2'2'-trihalogenethyl)-4-halocyclobutan-1-ones which can be produced by the improved method, as well as new intermediates which can be used for their production.

Ifølge den fremgangsmåten som er åpenbart i forannevnte patent-ansøkning kan 2-(2'^ 2 '.} 2 -trihalogenetyl)-4-halogen-cyklobutan-l-oner med formelen I According to the method which is obvious in the aforementioned patent application, 2-(2'^2'.}2-trihaloethyl)-4-halo-cyclobutan-1-ones of the formula I

hvor en av restene R-^og R2betyr metyl og den andre hydrogen eller metyl., eller R-^og R2tilsammen en alkylengruppe med 2 til 4 karbonatomer, og X og Y hver er klor eller brom, hvor dog, where one of the residues R-^ and R 2 means methyl and the other hydrogen or methyl., or R-^ and R 2 together an alkylene group with 2 to 4 carbon atoms, and X and Y are each chlorine or bromine, where, however,

når X er brom, må Y alltid likeledes være brom. when X is bromine, Y must also always be bromine.

Forbedringen og den videre utformning av denne fremgangsmåten består ifølge foreliggende oppfinnelse i fremskaffelsen av en fremgangsmåte ved fremstilling av 2-(2',2<1>,2<1->tribrometyl)-4-klorcyklobutan-l-oner med formelen Ia The improvement and further design of this method consists, according to the present invention, in the provision of a method for the production of 2-(2',2<1>,2<1->tribromethyl)-4-chlorocyclobutan-1-ones with the formula Ia

I IN

hvor en av restene R1og R2betyr metyl og den andre hydrogen eller metyl eller R-^og R2tilsammen en alkylengruppe med 2 til 4 karbonatomer. 2-(2',2',2'-tribrometyl)4-klorcyklobutan-l-onene med formel Ia er verdifulle mellomprodukter som i likhet med de ifølge fremgangsmåten ved forannevnte ansøkning fremstillbare 2-(2<1>,2',2'-tribrometyl)-4-bromcyklobutan-l-oner med formelen I kan overføres ved oppvarmning med baser, som alkalimetallhydroksyder og alkalimetallalko-holater, på kjent måte (Favorski-reaksjon) i 2-(2<*>2' dibrom-vinyl)-cyklopropan-l-karbonsyrer henholdsvis deres estere, som på sin side ved den videre omsetning med egnete alkoholer, f. eks. m-fenoksy-a-cyanobenzylalkohol, går over i insekticid virksomme estere. 2-(2<1>,2',2'-tribrometyl)-4-klorcyklobutan-l-oner med formelen Ia kan dog erholdes i vesentlig bedre utbytte enn de tilsvarende 2-(2',2',2'-tribrometyl)-4-bromcyklobutan-l-oner med formel I. Derfor er også 2-(2',2'— dibromvinyl)-cyklo-propan-l-karbonsyrer og deres insekticid virksomme estere lette-re tilgjengelige over de ifølge oppfinnelsen fremstillbare 2-(2<1>,2',2<1->tribrometyl-4-klorcyklobutanl-loner med formelen Ia i bedre utbytte enn over 2-(2<1>,2<1>,2'-tribrometyl)-4-bromcyklo-butan-l-onene med formel I. Insekticid virksomme 2-(2',2'-dibromvinyl)-cyklopropan-l-karbonsyreestere er f.eks. beskrevet i DOS 2.326.077 og 2.439.177. 2-(2',2',2'-tribrometyl)-4-klorcyklobutan-l-onene med formelen Ia fremstilles ifølge foreliggende oppfinnelse på den måte at man omsetter 2-klor-4,4,4-tribromsmørsyreklorid med formelen II I I i nærvær av en organisk base med et olefin med formelen III where one of the radicals R 1 and R 2 means methyl and the other hydrogen or methyl or R 1 and R 2 together an alkylene group with 2 to 4 carbon atoms. The 2-(2',2',2'-tribromethyl)4-chlorocyclobutan-1-ones of formula Ia are valuable intermediates which, like the 2-(2<1>,2',2 '-tribromethyl)-4-bromocyclobutan-1-ones of the formula I can be transferred by heating with bases, such as alkali metal hydroxides and alkali metal alcohols, in a known manner (Favorski reaction) in 2-(2<*>2' dibromo-vinyl )-cyclopropane-1-carboxylic acids or their esters, which in turn by further reaction with suitable alcohols, e.g. m-phenoxy-a-cyanobenzyl alcohol, turns into insecticide-active esters. 2-(2<1>,2',2'-tribromethyl)-4-chlorocyclobutan-1-ones with the formula Ia can, however, be obtained in significantly better yields than the corresponding 2-(2',2',2'-tribromethyl )-4-bromocyclobutan-1-ones with formula I. Therefore, 2-(2',2'-dibromovinyl)-cyclopropane-1-carboxylic acids and their insecticidally active esters are also more readily available than the 2 that can be prepared according to the invention -(2<1>,2',2<1->tribromethyl-4-chlorocyclobutan-lones with the formula Ia in better yield than above 2-(2<1>,2<1>,2'-tribromethyl)-4 -bromocyclo-butan-1-ones of formula I. Insecticidally active 2-(2',2'-dibromovinyl)-cyclopropane-1-carboxylic acid esters are, for example, described in DOS 2,326,077 and 2,439,177. The 2',2',2'-tribromethyl)-4-chlorocyclobutan-1-ones of the formula Ia are prepared according to the present invention by reacting 2-chloro-4,4,4-tribromobutyric acid chloride of the formula II I I in the presence of an organic base with an olefin of formula III

hvor og R2har den under formel I angitte betydning, til where and R2 has the meaning given under formula I, to

et 2-(2',2<1>,2<1->tribrometyl)-2-klorcyklobutan-l-on med formelen a 2-(2',2<1>,2<1->tribromethyl)-2-chlorocyclobutan-1-one of the formula

IV IV

hvor R-^ og R2har den'under formel I angitte betydning, og deretter omleirer dette i nærvær av en katalysator i et 2-(2<1>,2',2<1->tribrometyl)-4-klorcyklobutan-l-on med formelen I. where R-1 and R2 have the meaning given under formula I, and then rearranges this in the presence of a catalyst in a 2-(2<1>,2',2<1->tribromethyl)-4-chlorocyclobutane-1- on with the formula I.

2-klor-4,4,4-tribromsmørsyrekloridet med formel II er en ny forbindelse. Det kan fremstilles idet man først overfører 4,4,4-tribromsmørsyre ved omsetning med et uorganisk syreklorid i 4,4,4-tribromsmørsyreklorid og deretter klorerer dette i ct-stilling. The 2-chloro-4,4,4-tribromobutyric acid chloride of formula II is a new compound. It can be prepared by first transferring 4,4,4-tribromobutyric acid by reaction with an inorganic acid chloride into 4,4,4-tribromobutyric acid chloride and then chlorinating this in the ct position.

Det som utgangsmateriale nødvendige 4,4,4-tribromsmørsyre kan erholdes ved omsetning av bromoform med akrylonitril og etter-følgende hydrolyse av det dannete 4,4,4—tribromsmørsyrenitril The 4,4,4-tribromobutyric acid required as starting material can be obtained by reacting bromoform with acrylonitrile and subsequent hydrolysis of the formed 4,4,4-tribromobutyric acid nitrile

(J.Amer.Chem.Soc. 67, 601-602 (1945)). (J. Amer. Chem. Soc. 67, 601-602 (1945)).

Som uorganiske syreklorider kan anvendes fosfortriklorid, fos-foroksyklorid, fosgen, tionylklorid og oksalylklorid. Omsetningen av 4,4,4-tribromsmørsyre med det uorganiske syreklorid utføres med fordel i nærvær av en katalytisk mengde dimetylformamid. Som løsningsmiddel kan tjene et overskudd av uorganisk syreklorid. As inorganic acid chlorides, phosphorus trichloride, phosphorus oxychloride, phosgene, thionyl chloride and oxalyl chloride can be used. The reaction of 4,4,4-tribromobutyric acid with the inorganic acid chloride is advantageously carried out in the presence of a catalytic amount of dimethylformamide. An excess of inorganic acid chloride can serve as a solvent.

Kloreringen av 4,4,4-tribromsmørsyrekloridet i 2-stilling gjen-nomføres på vanlig måte. Som kloreringsmiddel kan f.eks. anvendes fritt klor eller N-klorsuccinimid. Et foretrukket klore- The chlorination of the 4,4,4-tribromobutyric acid chloride in the 2-position is carried out in the usual way. As a chlorinating agent, e.g. free chlorine or N-chlorosuccinimide is used. A preferred chlorine-

I I I I

ringsmiddel er N-klorsuccinimid. Kloreringen kan gjennomføres' uten isolering av A,4,4-tribromsmørsyrekloridet umiddelbart etter omsetningen av 4,4,4-tribromsmørsyre med det uorganiske syreklorid i overskytende uorganisk syreklorid som løsnings-middel. Man får dog et renere produkt når man isolerer 4,4,4-tribromsmørsyrekloridet og etterpå utfører kloreringen separat. Kloreringen utføres ved en temperatur fra 40 til 90°C, fortrinnsvis 60 til 70°C. Det er fordelaktig å bestråle reaksjonsblandingen under kloreringen med UV-lys eller tilsette noen kjente radikalstarter, f.eks. dibenzoylperoksyd eller azobisisobuty-ronitril. ringing agent is N-chlorosuccinimide. The chlorination can be carried out without isolating the A,4,4-tribromobutyric acid chloride immediately after the reaction of 4,4,4-tribromobutyric acid with the inorganic acid chloride in excess inorganic acid chloride as solvent. However, a cleaner product is obtained when the 4,4,4-tribromobutyric acid chloride is isolated and afterwards the chlorination is carried out separately. The chlorination is carried out at a temperature from 40 to 90°C, preferably 60 to 70°C. It is advantageous to irradiate the reaction mixture during the chlorination with UV light or to add some known radical initiators, e.g. dibenzoyl peroxide or azobisisobutyronitrile.

Omsetningen.av 2-klor-4,4,4-tribromsmørsyreklorid med formelen II med olefiner med formelen III foretas fordelaktig i nærvær av et inert, organisk løsningsmiddel. Egnete sådanne er f.eks. eventuelt halogenerte aromatiske eller alifatiske hydrokarboner, som benzen, toluen, xylener, klorbenzen, diklor- og triklorbenzener, n-pentan, n-heksan, n-oktan, metylenklorid, kloroform, karbontetraklorid, 1,1,2,2-tetrakloretan og trikloretylen. Ytterligere egnete løsningsmidler er cykloalifatiske hydrokarboner, som cyklopentan eller cykloheksan, cykloalifatiske ketoner, som cyklopentanon og cykloheksanon, samt alifatiske ketoner, alifatiske og cykliske etere, alkylnitriler og 3-alkoksypropionitriler med 1 eller 2 karbonatomer i alkoksy-gruppen, spesielt acetonitril og 3-metoksypropionitril. The reaction of 2-chloro-4,4,4-tribromobutyric acid chloride of the formula II with olefins of the formula III is advantageously carried out in the presence of an inert, organic solvent. Suitable such are 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-tetrachloroethane and trichloroethylene . 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 .

Spesielt egnete løsningsmidler er alifatiske, cykloalifatiske og aromatiske hydrokarboner, frem for alt alkaner med 5 til 8 karbonatomer, benzen og toluen og spesielt n-heksan og cykloheksan. Particularly suitable solvents are aliphatic, cycloaliphatic and aromatic hydrocarbons, above all alkanes with 5 to 8 carbon atoms, benzene and toluene and especially n-hexane and cyclohexane.

Som løsningsmiddel kan dog også overskytende olefin med formelen III anvendes. As a solvent, however, excess olefin with the formula III can also be used.

Egnete organiske baser i hvis nærvær omsetningen av 2-klor-4,4,4-tribromsmørsyrekloridet med formelen II utføres med et olefin med formelen III, er eksempelvis tertiære aminer, frem for alt trialkylaminer med hver 1 til 4 karbonatomer, spesielt 2 til 4 karbonatomer^i alkylgruppene, cykloske aminer, som Suitable organic bases in the presence of which the reaction of the 2-chloro-4,4,4-tribromobutyric acid chloride of the formula II is carried out with an olefin of the formula III are, for example, tertiary amines, above all trialkylamines each having 1 to 4 carbon atoms, especially 2 to 4 carbon atoms^in the alkyl groups, cyclic amines, which

i pyridin, kinolin, N-alkyl-pyrrolidiner, N-alkyl-piperidiner, in pyridine, quinoline, N-alkyl-pyrrolidines, N-alkyl-piperidines,

N,N-dialkyl-piperaziner og N-alkylmorfoliner eller dialkylani-liner med 1 eller 2 karbonatomer i alkylgruppene, som N-metyl-pyrrolidin, N-etyl-piperidin, N^N<1->dimetyl-piperazin, N-etyl-morfolin og N,N-dimetylanilin, samt bicykliske amidiner, som 1,5-diazabicyklo[5.4.0]undec-5-en og 1,5-diazabicyklo[4.3.0]-non-5-en, og bicykliske diaminer som 1,4-diazabicyklo[2.2.2]-oktan. N,N-dialkyl-piperazines and N-alkylmorpholines or dialkylanilines with 1 or 2 carbon atoms in the alkyl groups, such as N-methyl-pyrrolidine, N-ethyl-piperidine, N^N<1->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-diazabicyclo[4.3.0]-non-5-ene, and bicyclic diamines as 1,4-diazabicyclo[2.2.2]-octane.

Omsetningen av 2-klor-4,4,4-tribromsmørsyrekloridet med formelen II med olefiner med formelen III utføres fortrinnsvis i nærvær av trialkylaminer med 1 til 4 karbonatomer i alkylgruppene. Spesielt egnete baser er trietylåmin og pyridin. The reaction of the 2-chloro-4,4,4-tribromobutyric acid chloride of the formula II with olefins of the formula III is preferably carried out in the presence of trialkylamines with 1 to 4 carbon atoms in the alkyl groups. Particularly suitable bases are triethylamine and pyridine.

Den organiske base anvendes i minst ekvimolar mengde eller i et lite overskudd med hensyn til 2-klor-4,4,4-tribromsmørsyre-kloridet med formel II. The organic base is used in at least an equimolar amount or in a small excess with respect to the 2-chloro-4,4,4-tribromobutyric acid chloride of formula II.

Olefinene med formelen III anvendes likeledes i minst ekvimolar mengde med hensyn til 2-klor-4,4,4-tribromsmørsyrekloridet med formelen II. Det er dog generelt fordelaktig å anvende et overskudd av olefin, hvorved olefinet, som allerede nevnt, også kan tjene som løsningsmiddel. Ved anvendelse av svakt flyktige olefiner kan reaksjonen utføres under trykk. The olefins of the formula III are likewise used in at least an equimolar amount with respect to the 2-chloro-4,4,4-tribromobutyric acid chloride of the formula II. However, it is generally advantageous to use an excess of olefin, whereby the olefin, as already mentioned, can also serve as a solvent. When using slightly volatile olefins, the reaction can be carried out under pressure.

Som olefiner med formelen III kommer spesielt de i betraktning, i hvilke en av restene R, og R2betyr metyl og den andre hydrogen eller metyl, eller R-^og R2tilsammen betyr en alkylengruppe med 2 til 3 karbonatomer, nemlig isobutylen, propen, metylencyklopropan og metylencyklobutan. Særlig foretrukket er isobutylen og metylencyklopropan. As olefins of the formula III, those in which one of the radicals R, and R2 means methyl and the other hydrogen or methyl, or R-^ and R2 together mean an alkylene group with 2 to 3 carbon atoms, namely isobutylene, propene, methylenecyclopropane and methylenecyclobutane. Particularly preferred are isobutylene and methylenecyclopropane.

Reaksjonstemperaturene kan varieres innen for vie grenser. De ligger i alminnelighet mellom 0 og 200°C, fortrinnsvis mellom 20 og 160°C. The reaction temperatures can be varied within wide limits. They are generally between 0 and 200°C, preferably between 20 and 160°C.

2-(2,2',2<1->tribrometyl)-2-klorcyklobutan-l-onene med formelen IV er likeledes nye forbindelser. The 2-(2,2',2<1->tribromethyl)-2-chlorocyclobutan-1-ones of the formula IV are also new compounds.

i in

j j

1 1

Som katalysatorer for omleiringen av de først erholdte 2-(2 2 2 '-tribrometyl).-2-klorcyklobutan-loner med formelen IV i 2-(2',2<1>,2'-tribrometyl)-4-klorcyklobutan-l-oner med formelen I kan anvendes syrer, baser eller kvaternære ammoniumhalogenider. As catalysts for the rearrangement of the first obtained 2-(2 2 2 '-tribromethyl).-2-chlorocyclobutanes of the formula IV in 2-(2',2<1>,2'-tribromethyl)-4-chlorocyclobutane- Ions with the formula I can be used acids, bases or quaternary ammonium halides.

Omleiringen ifølge oppfinnelsen av 2-(2',2',2'-tribrometyl)-2-klorcyklobutan-l-oner med- formelen IV til 2-(2',2',2<1->tribrom-etyl) -4-klorcyklobutan-l-oner med formelen I er uventet og ikke kjent hos cyklobutanoner som er monohalogenerte i a-stilling. Omleiringen forløper i utmerket, ofte kvantitativt utbytte. The rearrangement according to the invention of 2-(2',2',2'-tribromomethyl)-2-chlorocyclobutan-1-ones with the formula IV to 2-(2',2',2<1->tribromo-ethyl)- 4-chlorocyclobutan-1-ones of the formula I are unexpected and not known in cyclobutanones which are monohalogenated in the a-position. The resettlement proceeds with excellent, often quantitative results.

Omleringen ifølge oppfinnelsen av 2-(2',2',2'-tribrometyl)-2-klorcyklobutan-l-oner med formel IV i 2-(2<1>,2<1>,2<1->tribrometyl)-4-klorcyklobutan-l-oner med formelen I utføres fortrinnsvis i nærvær av basiske katalysatorer. Som basiske katalysatorer kommer organiske baser i betraktning, som primære, sekundære og spesielt tertiære aminer med formelen The rearrangement according to the invention of 2-(2',2',2'-tribromethyl)-2-chlorocyclobutan-1-ones of formula IV in 2-(2<1>,2<1>,2<1->tribromethyl) -4-chlorocyclobutan-1-ones of the formula I are preferably carried out in the presence of basic catalysts. As basic catalysts, organic bases come into consideration, such as primary, secondary and especially tertiary amines with the formula

hvor Q betyr alkyl med 1 til 8 karbonatomer, cykloalkyl med 5 til 6 karbonatomer, benzyl eller fenyl og Q2og Q2uavhengig where Q means alkyl with 1 to 8 carbon atoms, cycloalkyl with 5 to 6 carbon atoms, benzyl or phenyl and Q 2 and Q 2 are independent

av hverandre betyr hydrogen eller alkyl med 1 til 8 karbonatomer. Egnete basiske katalysatorer er f.eks. trietylamin, tri-n-butylamin, tri-isopentylamin, tri-n-oktylamin, N,N-dimetyl-cykloheksylamin, N,N-dimetylbenzylamin, N,N-dimetyl-2-etylhek-sylamin, N,N-dietylanilin, såvel som ytterligere cykliske aminer, som pyridin, kinolin, lutidin, N-alkylmorfoliner, som N-metylmorfoliner, N-alkylpiperidiner, som N-metyl- og N-etyl-piperidin, N-alkylpyrrolidiner som N-metyl- og N-etylpyrrolidin, diaminer, som N,N,N<*>,N'-tetrametyletylendiamin, N,N,N',N'-tetrametyl-1,3-diaminobutan, N,N<1->dialkylpiperaziner som N,N'-dimetylpiperazin, bicykliske aminer, som 1,4-diazabicyklo-[2,2,2]oktan og bicykliske amidiner, som 1,5-diazabicyklo[5.4.0]-undec-5-en og 1,5-diazabicyklo[4.3.0]non-5-en, og endelig polymere basiske forbindelser, som p-dimetylaminometylpolystyren. of each other means 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-dimethyl-cyclohexylamine, N,N-dimethylbenzylamine, N,N-dimethyl-2-ethylhexylamine, N,N-diethylaniline, as well as further cyclic amines, such as pyridine, quinoline, lutidine, N-alkylmorpholines, such as N-methylmorpholines, N-alkylpiperidines, such as N-methyl- and N-ethyl-piperidine, N-alkylpyrrolidines such as N-methyl- and N-ethylpyrrolidine , diamines, such as N,N,N<*>,N'-tetramethylethylenediamine, N,N,N',N'-tetramethyl-1,3-diaminobutane, N,N<1->dialkylpiperazines such as N,N'- dimethylpiperazine, bicyclic amines, such as 1,4-diazabicyclo-[2,2,2]octane and bicyclic amidines, such as 1,5-diazabicyclo[5.4.0]-undec-5-ene and 1,5-diazabicyclo[4.3. 0]non-5-ene, and finally polymeric basic compounds, such as p-dimethylaminomethylpolystyrene.

Videre egnete basiske katalysatorer for omleiringen ifølge oppfinnelsen av et 2-(2<1>,2<1>,2<1->tribrometyl)-2-klorcyklobutan-l-on Furthermore, suitable basic catalysts for the rearrangement according to the invention of a 2-(2<1>,2<1>,2<1->tribromethyl)-2-chlorocyclobutan-1-one

med formel IV i et 2-(2',2',2<1->tribrometyl)-4-klorcyklobutan-1-on med formel I er fosfiner, spesielt trialkylfosfiner, eksempelvis tributylfosfin. with formula IV in a 2-(2',2',2<1->tribromethyl)-4-chlorocyclobutan-1-one with formula I are phosphines, especially trialkylphosphines, for example tributylphosphine.

Som sure katalysatorer for omleiringen av 2-(2<1>,2<1>,2'-tribrom-etyl) -2-klorcyklobutan-l-oner med formelen IV i tribrometyl-klorcyklobutan-l-oner med formelen I kan anvendes uorganiske eller organiske protonsyrer. Egnete uorganiske protonsyrer er eksempelvis hydrogenhalogenidsyrer, som hydrogenklorid, hydrogen-bromid, hydrogenfluorid og hydrogenjodid, salpetersyre, fosforsyre og svovelsyre. Foretrukné uorganiske protonsyrer er hydrogenhalogenidsyrer . As acid catalysts for the rearrangement of 2-(2<1>,2<1>,2'-tribromoethyl)-2-chlorocyclobutan-1-ones of the formula IV into tribromethyl-chlorocyclobutan-1-ones of the formula I can be used inorganic or organic protonic acids. Suitable inorganic protonic acids are, for example, hydrogen halide 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.

Anvendes syrer eller baser i overskudd så kan de også tjene som løsningsmiddel. If acids or bases are used in excess, they can also serve as solvents.

Videre kan salter av protonsyrer, spesielt hydrogenhalogenidsyrer, med ammoniakk eller en nitrogenholdig organisk base samt kvaternære ammoniumhalogenider, kvaternære fosfoniumhalogenider og sulfoniumhalogenider anvendes. Egnete nitrogenholdige organiske baser er alifatiske, cykloalifatiske, aralifatiske og aromatiske primære, sekundære og tertiære aminer samt heterocykliske nitrogenbaser. Som eksempler kan nevnes: primære alifatiske aminer med opp til 12 C-atomer, som metylamin, etylamin, n-butylamin, n-oktylamin, n-dodecylamin, heksametylendiamin, cyklohek-sylamin, benzylamin; sekundære alifatiske aminer med opp til 12 C-atomer, som dimetylamin, dietylamin, di-n-propylamin, dicyklo-heksylamin, pyrrolidin, piperidin, piperazin, morfolin; tertiære alifatiske aminer særlig trialkylaminer 1 til 4 C-atomer i hver alkyldel, som trietylamin, tri-n-butylamin, N-metylpyrrolidin^N-metylmorfolin, 1,4-diazabicyklo[2,2,2]oktan, chinuklidin; eventuelt substituerte primære, sekundære og tertiære aromatiske aminer, som anilin, toluidin, naftylamin, N-metylanilin, di-fenylamin og N,N-dietylanilin, videre pyridin, pikolin, indolin og kinolin. Furthermore, salts of protonic acids, especially hydrogen halide acids, with ammonia or a nitrogen-containing organic base as well as quaternary ammonium halides, quaternary phosphonium halides and sulfonium halides can be used. Suitable nitrogen-containing organic bases are aliphatic, cycloaliphatic, araliphatic and aromatic primary, secondary and tertiary amines as well as heterocyclic nitrogen bases. Examples may be mentioned: 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, morpholine; tertiary aliphatic amines especially trialkylamines 1 to 4 C atoms in each alkyl part, such as triethylamine, tri-n-butylamine, N-methylpyrrolidine^N-methylmorpholine, 1,4-diazabicyclo[2,2,2]octane, quinuclidine; optionally substituted primary, secondary and tertiary aromatic amines, such as aniline, toluidine, naphthylamine, N-methylaniline, di-phenylamine and N,N-diethylaniline, further pyridine, picoline, indoline and quinoline.

I 1<1>Som kvartære fosfoniumhalogenider kommer f.eks. i betraktning: heksadecyltributylfosfoniumbromid, metyl- og etyl-tri-fenyl-fosfoniumbromid; som sulfoniumhalogenid, f.eks. trimetylsul-foniumjodid. In 1<1>As quaternary phosphonium halides, e.g. in consideration: hexadecyltributylphosphonium bromide, methyl- and ethyl-tri-phenyl-phosphonium bromide; as sulfonium halide, e.g. trimethylsulfonium iodide.

Foretrukket er salter med formelen Salts with the formula are preferred

hvor M betyr fluor, brom eller jod, spesielt klor, where M means fluorine, bromine or iodine, especially chlorine,

Q4hydrogen, alkyl med 1-18 C-atomer, cykloheksyl, benzyl, fenyl eller naftyl og Q4hydrogen, alkyl with 1-18 C atoms, cyclohexyl, benzyl, phenyl or naphthyl and

Q5, Qg og Q7uavhengig av hverandre hydrogen eller alkyl med 1-18 C-atomer, Q5, Qg and Q7 independently of each other hydrogen or alkyl with 1-18 C atoms,

samt N-alkyl-pyridiniumhalogenider med 1-18 C-atomer i alkylet, spesielt i de tilsvarende klorider. as well as N-alkyl pyridinium halides with 1-18 C atoms in the alkyl, especially in the corresponding chlorides.

Eksempler på slike salter er: ammoniumklorid, ammoniumbromid, metylaminhydroklorid, cykloheksylaminhydroklorid, anilinhydro-klorid, dimetylaminhydroklorid, di-isobutylaminohydroklorid, trietylaminhydroklroid, trietylaminhydrobromid, tri-n-oktyl-aminhydroklorid, benzyl-dimetylaminhydroklorid, tetrametyl-, tetraetyl-, tetra-n-propyl-, tetra-n-butylammoniumklorid, -bro-mid og -jodid, trimetyl-heksadecylammoniumklorid, benzyldimetyl-heksadecylammoniumklroid, benzyldimetyltetradecyklammoniumklorid, benzyl-trimetyl-, trietyl- og tri-n-butylammoniumklorid, n-bu^tyl-tri-n-propylaramoniumbromid, oktadecy 1 trimety 1 ammoniumbromid, fenyltrimetylammoniumbromid eller -klorid, heksadecylpyridinium-brom og -klorid. Examples of such salts are: ammonium chloride, ammonium bromide, methylamine hydrochloride, cyclohexylamine hydrochloride, aniline hydrochloride, dimethylamine hydrochloride, di-isobutylamino hydrochloride, triethylamine hydrochloride, triethylamine hydrobromide, tri-n-octylamine hydrochloride, benzyl-dimethylamine hydrochloride, tetramethyl-, tetraethyl-, tetra-n- propyl-, tetra-n-butylammonium chloride, -bromide and -iodide, trimethyl-hexadecylammonium chloride, benzyldimethyl-hexadecylammonium chloride, benzyldimethyltetradecylammonium chloride, benzyl-trimethyl-, triethyl- and tri-n-butylammonium chloride, n-bu^tyl-tri-n -propylarammonium bromide, octadecy 1 trimethy 1 ammonium bromide, phenyltrimethylammonium bromide or chloride, hexadecylpyridinium bromide and chloride.

Som.ytterligere ko-katalysatorer kan man anvende alkalimetall-halogenider som kaliumjodid, natriumjodid, litiumjodid, kalium-broraid, natriumbromid, litiumbromid, kaliumklorid, natriumklo-rid, litiumklorid, kaliumfluorid, natriumfluorid og litium-fluorid. 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 as further co-catalysts.

Disse ko-katalysatorer katalyserer reaksjonen også i fravær "av ovennevnte ammoniumsalter, dog er da tilsetninger av åpen-! kjedete eller makrocykliske polyestere (krone-etere) fordelaktig for raskt forløp. Eksempler på slike krone-etere er: 15-crown-5, 18-crown-6, dibenzo-18-crown-6, dicykloheksyl-18-crown-6, 5,6,14,15-dibenzo-7,13-diaza-l,4-dioksa-cyklopenta-deka-5,14-dien. These co-catalysts catalyze the reaction also in the absence of the above-mentioned ammonium salts, however, then additions of open-chain or macrocyclic polyesters (crown ethers) are advantageous for rapid progress. 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-cyclopenta-deca-5, the 14th.

Mengden av anvendt katalysator kan variere innen vide grenser. I mange tilfeller er det tilstrekkelig når katalysatoren fore-ligger i spor. Generelt anvendes katalysatoren dog foretrukket i en mengde på ca. 0,1 til 15 vekts%, beregnet på forbindelsen med formel VI. The amount of catalyst used can vary within wide limits. In many cases, it is sufficient when the catalyst is present in traces. In general, however, the catalyst is preferably used in an amount of approx. 0.1 to 15% by weight, calculated on the compound of formula VI.

Omleiringen kan foretas både i smelte og i et inert organisk løsningsmiddel. The redeposition can be carried out both in melt and in an inert organic solvent.

Reaksjonstemperaturene for omleiringen i smeiten ligger i alminnelighet mellom 60 og 150°C, spesielt 80 og 130°C. The reaction temperatures for the rearrangement in the smelting are generally between 60 and 150°C, especially 80 and 130°C.

For omleiringen i smeiten er egnete katalysatorer frem for alt de foran nevnte organiske baser, spesielt trialkylaminer med 1-8 C-atomer i hver alkyldel, videre salter av hydrogenhalogenidsyrer med ammoniakk eller organiske nitrogenholdige baser, som trialkylaminhydroklorider og -bromider med 1-8 C-atomer i hver alkyldel, og helt spesielt tetraalkylammoniumhalogenider, frem for alt -klorider, -bromider og -jodider med 1-18 C-atomer i hver alkyldel. For the rearrangement in the smelting, suitable catalysts are above all the aforementioned organic bases, especially trialkylamines with 1-8 C atoms in each alkyl part, 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 each alkyl part, and especially tetraalkylammonium halides, above all -chlorides, -bromides and -iodides with 1-18 C atoms in each alkyl part.

Egnete inerte organiske løsningsmidler er f.eks. Suitable inert organic solvents are e.g.

- eventuelt nitrerte eller halogenerte alifatiske, cykloalifatiske eller aromatiske hydrokarboner, som n-heksan, n-pentan, cykloheksan, benzen, toluen, xylener, nitrobenzen, kloroform, karbontetraklorid, trikloretylen, 1,1,2,2-tetrakloretan, nitro-metan, klorbenzen, diklorbenzener og triklorbenzener; - lavere alifatiske alkoholer, f.eks. slite med opp til 6 C-atomer, som metanol etanol, propanol, isopropanol, butanoler og pentanoler; I - alifatiske dioler, som etylenglykol og dietylenglykol: - etylenglykolmo.noalkyleter og dietylenglykolmonoalkyleter med 1-4 C-atomer i hver alkyldel, som etylenglykolmonometyl-og -monoetyleter, dietylenglykolmonometyl- og -monoetyleter; - cyklikske a ider, som N-metyl-2-pyrrolidon, N-acetyl-2-pyrro-lidon og N-metyl-£-kaprolaktam; -amider av kullsyre, som tetrametylurea og dimorfolinkarbonyl; - amider av fosforsyrling>fosforsyre, fenylfosfonsyre eller av alifatiske fosfonsyrer med 1-3 C-atomer i syredelen, som.fos-forsyretriamid, fosforsyretris(dimetylamid), fosforsyretrimor-folid, fosforsyretripyrrolinid, fosforsyre-bis(dimetylamid)-morfolid, fosforsyre-dimetylamid-dietylamid-morfolid, fosforsyrling-tris(dimetylamid), tetrametyldiamid av metanfosfonsyre; - amider av svovelsyre, av alifatiske eller aromatiske sulfonsyrer, som tetrametylsulfamid, dimetylamid av metansulfonsyre eller p-toluensulfonsyreamid; - svovelholdige løsningsmidler, som organiske sulfoner og sulf-oksyder, f.eks. dimetylsulfoksyd og sulfolan; - alifatiske og aromatiske nitriler, 3-alkoksypropionitriler, alifatiske ketoner, alkyl- og alkoksyalkylestere av alifatiske monokarbonsyrer, cykloske etere, dialkyleter, N,N-disubstituerte amider av alifatiske monokarbonsyrer og etylenglykol- og diety-lenglykoldialkyleter av den under fremgangsmåtetrinn 1) - optionally nitrated or halogenated aliphatic, cycloaliphatic or aromatic hydrocarbons, such as n-hexane, n-pentane, cyclohexane, benzene, toluene, xylenes, nitrobenzene, chloroform, carbon tetrachloride, trichloroethylene, 1,1,2,2-tetrachloroethane, nitro-methane , chlorobenzene, dichlorobenzenes and trichlorobenzenes; - lower aliphatic alcohols, e.g. struggle with up to 6 C atoms, such as methanol ethanol, propanol, isopropanol, butanols and pentanols; I - aliphatic diols, such as ethylene glycol and diethylene glycol: - ethylene glycol monoalkyl ether and diethylene glycol monoalkyl ether with 1-4 C atoms in each alkyl part, such as ethylene glycol monomethyl and -monoethyl ether, diethylene glycol monomethyl and -monoethyl ether; - cyclic aides, such as N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone and N-methyl-£-caprolactam; -amides of carbonic acid, such as tetramethylurea and dimorpholinecarbonyl; - amides of phosphoric acid>phosphoric acid, phenylphosphonic acid or of aliphatic phosphonic acids with 1-3 C atoms in the acid part, such as phosphoric acid triamide, phosphoric acid tris(dimethylamide), phosphoric acid trimorfolide, 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; - sulphur-containing solvents, such as organic sulphones and sulph-oxides, e.g. dimethyl sulfoxide and sulfolane; - aliphatic and aromatic nitriles, 3-alkoxypropionitriles, 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 that under method step 1)

nevnte type. said type.

For omleiringen i nærvær av en sur katalysator anvender man med fordel polare løsningsmidler, spesielt lavere alkoholer, som metanol, etanol og butanoler, N,N-dialkylamider av alifatiske monokarbonsyrer med 1-3 C-atomer i syredelen, spesielt N,N-dimetylformamid, eller dialkylsulfoksyder, som dimetylsulfoksyd. For the rearrangement in the presence of an acidic catalyst, 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 dialkyl sulfoxides, such as dimethyl sulfoxide.

I aprotiske, sterkt polare løsningsmidler som de forannevnte N,N-disubstituerte amider av alifatiske monokarbonsyrer, cykliske amider, amider av kullsyre, amider av fosforsyrling, fosforsyre, fenylfosfonsyre eller av alifatiske fosfonsyrer, amider av svovelsyre eller av alifatiske eller aromatiske sulfonsyrer, samt dialkylsulfoksyder, som dimetylsulfoksyd, forløper reaksjonen også uten tilsetning av base eller syre. I disse tilfeller virker■løsningsmidlet som katalysator. i In aprotic, strongly polar solvents such as the aforementioned N,N-disubstituted amides of aliphatic monocarboxylic acids, cyclic amides, amides of carbonic acid, amides of phosphoric acid, phosphoric acid, phenylphosphonic acid or of aliphatic phosphonic acids, amides of sulfuric acid or of aliphatic or aromatic sulfonic acids, as well as dialkyl sulfoxides , such as dimethylsulfoxide, the reaction also proceeds without the addition of base or acid. In these cases,■the solvent acts as a catalyst. in

Ii I alminnelighet tilsettes dog ved omleiringen i nærvær av et' Ii In general, however, is added during the rearrangement in the presence of a

inert organisk løsningsmiddel en katalysator, fortrinnsvis en organisk base med en pKa-verdi på over 9, spesielt trialkylaminer med 1-8 C-atomer i alkyldelen, som trietylamin, tri-n-butylamin og tri-n-oktylamin; videre hydrogenhalogenidsyrer, spesielt HC1 og HBr, samt tetraalkylammoniumhalogenider, spesielt -klorider, -bromider og -jodider, med 1-18 C-atomer i alkyldelen. inert organic solvent a catalyst, preferably an organic base with a pKa value above 9, especially trialkylamines with 1-8 C atoms in the alkyl part, such as triethylamine, tri-n-butylamine and tri-n-octylamine; further hydrogen halide acids, especially HC1 and HBr, as well as tetraalkylammonium halides, especially -chlorides, -bromides and -iodides, with 1-18 C atoms in the alkyl part.

Særlig foretrukne løsningsmidler er alifatiske alkoholer med 1- 4 C-atomer, toluen, xylener, klorbenzen, dioksan,.acetonitril, 3-metoksypropionitril, etylenglykoldietyleter og di-isopropyl-keton. 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.

Reaksjonstemperaturene for omleiringen i nærvær av et inert organisk løsningsmiddel ligger vanligvis mellom ca. 0 og 150°C, fortrinnsvis mellom ca. 80 og 130°C. The reaction temperatures for the rearrangement in the presence of an inert organic solvent are usually between approx. 0 and 150°C, preferably between approx. 80 and 130°C.

Med fremgangsmåten ifølge oppfinnelsen blir nye, i 3-stilling substituerte, som mellomprodukter for fremstillingen av i 3-stilling substituerte 2-(2',2'~——dibromvinyl)-cyklopropankar-bonsyrederivater egnete 2-(2<1>,2',2'-tribrometyl)-4-klorcyklo-butan-l-oner med formel I tilgjengelige ut fra lett tilgjengelige utgangsmaterialer på enkel måte og i godt utbytte. For-løpet av fremgangsmåten ifølge oppfinnelsen er ytterst overra-skende og absolutt ikke å forutse, da det ved omsetningen av 2- klor-4,4,4-tribromsmørsyrekloridet med formel II henh. et derav ved avspaltning av hydrogenklorid in situ dannet klor-keten med et olefin med formelen III først dannes et for den videre omleiring i et i 3-stilling substituert 2-(2',2' —■—di-bromvinyl)-cyklopropankarbonsyrederivat uegnet 2-(2<1>,2',2<1->tri-brometyl) -2-klorcyklobutan-l-on med formelen IV, som så over ved en ny, ved i a-stilling monohalogenerte cyklobutanoner tid-ligere ikke observert omleiring i et for den videre omleiring til et i 3-stilling substituert 2— (2' , 2' dibromvinyl)cyklopro-pankarbonsyre-derivat egnet 2-(2<1>,2',2'-tribrometyl)-4-klor-cyklobutan-l-on med formelen I. With the method according to the invention, new, substituted in the 3-position, as intermediates for the preparation of substituted in the 3-position 2-(2',2'~——dibromovinyl)-cyclopropanecarboxylic acid derivatives 2-(2<1>,2 ',2'-tribromethyl)-4-chlorocyclo-butan-1-ones of formula I accessible from readily available starting materials in a simple manner and in good yield. The course of the method according to the invention is extremely surprising and absolutely not predictable, since in the reaction of the 2-chloro-4,4,4-tribromobutyric acid chloride with formula II acc. one of which by cleavage of hydrogen chloride in situ formed chloroketene with an olefin of the formula III first forms a for the further rearrangement in a 3-position substituted 2-(2',2'-■-dibromovinyl)-cyclopropanecarboxylic acid derivative unsuitable 2-(2<1>,2',2<1->tri-bromomethyl)-2-chlorocyclobutan-1-one of the formula IV, which saw above in a new monohalogenated cyclobutanones in the a-position previously not observed rearrangement in a suitable 2-(2<1>,2',2'-tribromomethyl)-4- chloro-cyclobutan-l-one of the formula I.

I IN

i in

■ De ut fra nye 2-(2<1>,2<1>,2'-tribrometyl)-4-klorcyklobutan-l-oner med formel I fremstillbare, i 3-stilling substituerte 2-(2',2'-dibromvinyl)-cyklopropankarbonsyrer og deres insekticid-virksomme estere kan beskrives ved den etterfølgende formel VIII. ■ The 3-position substituted 2-(2',2'- dibromovinyl) cyclopropane carboxylic acids and their insecticidally active esters can be described by the following formula VIII.

hvor X, og R2 'har de under formel I angitte betydningér, og R er hydrogen, alkyl med 1 til 4 karbonatomer eller en gruppe med formelen IX hvor R^betyr oksygen, svovel eller vinylengruppen, R^hydrogen, alkyl med 1 til 4 karbonatomer, benzyl, fenoksy eller fenyl-merkapto, R^hydrogen eller en alkylgruppe med 1 til 4 karbonatomer og Rg hydrogen, cyano eller etinyl eller, når en av restene R^og R2er metyl og den andre hydrogen eller metyl, er R2 vinylen-gruppen, R^fenoksy og R^hydrogen, også alkyl med 1 til 5 karbonatomer. where X, and R2' have the meanings given under formula I, and R is hydrogen, alkyl with 1 to 4 carbon atoms or a group with the formula IX where R^ means oxygen, sulfur or the vinylene group, R^hydrogen, alkyl with 1 to 4 carbon atoms, benzyl, phenoxy or phenyl-mercapto, R^ hydrogen or an alkyl group of 1 to 4 carbon atoms and R g hydrogen, cyano or ethynyl or, when one of the radicals R^ and R 2 is methyl and the other hydrogen or methyl, R 2 is vinylene- the group, R^phenoxy and R^hydrogen, also alkyl with 1 to 5 carbon atoms.

2-(21,2' dibromviny1)-cyklopropankarbonsyrederivatene med formelen VIII, hvor R betyr en gruppe med formelen.IX, egner seg for bekjempelse av forskjellige dyriske eller vegetabilske skadevesener, spesielt insekter. Egenskaper, anvendelsesområder og anvendelsesformer av disse virkestoffene er beskrevet i lit-teraturen (sml. f.eks. Nature, 246, 169-170 (1973) Nature, 248 710-711 (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 3.961.070; DOS 2.553.991, 2.439.177, 2.326.077 og 2.614.648). The 2-(21,2' dibromovinyl)-cyclopropanecarboxylic acid derivatives of the formula VIII, where R represents a group of the formula IX, are suitable for combating various animal or vegetable pests, especially insects. Properties, areas of application and forms of application of these active substances are described in the literature (cf. e.g. Nature, 246, 169-170 (1973) Nature, 248 710-711 (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 3,961,070; DOS 2,553,991, 2,439,177, 2,326,077 and 2,614,648).

ii Overføringen av 2-(2',2<1>,2'-tribrometyl)-4-klor-cyklobutan-l- I oner med formelen I i 2-(2',2' dibromvinyl)-cyklopropan-karbonsyrederivater med formelen VIII skjer på en i og for seg kjent måte ved oppvarmning i nærvær av egnete baser. Egnete baser er eksempelvis alkalimetall- og jordalkalimetallhydroksyder, som natriumhydroksyd, kaliumhydroksyd, kalsiumhydroksyd og ba-riumhydroksyd. Også alkalimetall- og jordalkalimetallkarbonater og -hydrogenkarbonater, som kalsiumkarbonat, bariumkarbonat, kaliumkarbonat, natriumkarbonat, natriumhydrogenkarbonat og ka-liumhydrogenkarbonat kan anvendes som baser. Ytterligere egnet som baser er alkoholater avledet fra resten R ifølge ovennevnte definisjon, spesielt de tilsvarende natrium- og kaliumalkoholater. Anvendelsen av slike alkoholater har den fordel at den tilsvarende ester erholdes umiddelbart, mens ved anvendelse av alkalimetall- og jordalkalimetallhydroksyder erholdes først saltene av disse baser med den dannete 2-(2',2'—— dibromvinyl)-cyklo-propankarbonsyre. Disse kan dog likeledes på enkel og i og for seg kjent måte, f.eks. ved overføring i det tilsvarende syreklorid og omsetning med en alkohol avledet fra resten R?over-føres i estere. ii The conversion of 2-(2',2<1>,2'-tribromomethyl)-4-chloro-cyclobutan-1- Iones of the formula I into 2-(2',2' dibromovinyl)-cyclopropane-carboxylic acid derivatives of the formula VIII takes place in a manner known per se by heating in the presence of suitable bases. Suitable bases are, for example, alkali metal and alkaline earth metal hydroxides, such as sodium hydroxide, potassium hydroxide, calcium hydroxide and barium hydroxide. Alkali metal and alkaline earth metal carbonates and hydrogen carbonates, such as calcium carbonate, barium carbonate, potassium carbonate, sodium carbonate, sodium hydrogen carbonate and potassium hydrogen carbonate can also be used as bases. Further suitable as bases are alcoholates derived from the radical R according to the above definition, especially the corresponding sodium and potassium alcoholates. The use of such alcoholates has the advantage that the corresponding ester is obtained immediately, while when using alkali metal and alkaline earth metal hydroxides, the salts of these bases are first obtained with the formed 2-(2',2'——dibromovinyl)-cyclopropanecarboxylic acid. However, these can also be done in a simple and per se known manner, e.g. by transfer into the corresponding acid chloride and reaction with an alcohol derived from the residue R? is transferred into esters.

Overføringen av et 2-(2<1>,2<1>,2'-tribrometyl)-4-klor-cyklobutan-1-on med formel I i et 2-(2',2' dibromvinyl)-cyklopropankar-bonsyrederivat med formelen VIII foretas avhengig av typen av anvendt base hensiktsmessig i vandig, vandig-organisk eller organisk medium, Når et alkalimetall- eller jordalkalimetallkarbonat anvendes som base, så utføres omsetningen i vandig eller vandig-organisk medium. Også omsetningen i nærvær av alkalimetall-eller jordalkalimetallhydroksyder og alkalimetallhydrogenkarbo-nater foretas med fordel i vandig eller vandig-organisk medium. Derved erholdes etter surgjøring av reaksjonsblandingen, f.eks. ved tilsetning av konsentrert saltsyre, de frie 2-(2<1>,2'-dibrom-vinyl) -cyklopropankarbonsyrer med formelen VIII (R = H). The conversion of a 2-(2<1>,2<1>,2'-tribromomethyl)-4-chloro-cyclobutan-1-one of formula I into a 2-(2',2' dibromovinyl)-cyclopropanecarboxylic acid derivative with the formula VIII is carried out depending on the type of base used appropriately in an aqueous, aqueous-organic or organic medium. When an alkali metal or alkaline earth metal carbonate is used as base, the reaction is carried out in an aqueous or aqueous-organic medium. The reaction in the presence of alkali metal or 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<1>,2'-dibromo-vinyl)-cyclopropanecarboxylic acids of the formula VIII (R = H).

Egnete løsningsmidler for omsetningen av 2-(2<1>,2<1>,2<1->tribrom-etyl) -4-klorcyklobutan-l-oner med formelen I i 2-(2<1>,2<1->dibrom-vinyl) -cyklopropankarbonsyrederivater med formelen VIII i vandig-organisk eller organisk medium er lavere alkoholer, f.eks. slike med 1 til 6 karbonatomer, benzylalkohol, alifatiske eller cykliske etere, som dietyleter, di-n-propyleter, di-isopropyl-l eter, tetrahydrofuran og dioksan, samt alifatiske, cykloalifa-.tiske eller aromatiske hydrokarboner, som n-pentan, n-heksan, cykloheksan, benzen, toluen og xylener. Suitable solvents for the reaction of 2-(2<1>,2<1>,2<1->tribromoethyl)-4-chlorocyclobutan-1-ones of the formula I in 2-(2<1>,2<1 ->dibromo-vinyl)-cyclopropanecarboxylic acid derivatives of formula VIII in aqueous-organic or organic medium are lower alcohols, e.g. those with 1 to 6 carbon atoms, benzyl alcohol, aliphatic or cyclic ethers, such as diethyl ether, di-n-propyl ether, di-isopropyl ether, tetrahydrofuran and dioxane, as well as aliphatic, cycloaliphatic or aromatic hydrocarbons, such as n-pentane, n-hexane, cyclohexane, benzene, toluene and xylenes.

Omsetningen av 2-(2<1>,2',2'-tribrometyl)-4-klorcyklobutan-l-oner med formelen I til 2-(2',21-dibromvinyl)-cyklopropankarbonsyre-derivater med formelen VIII foretas vanligvis ved det valgte reaksjonsmediets kokepunkt. Spesielt egnet er reaksjonstempera-turer mellom 40 og 120°C. The reaction of 2-(2<1>,2',2'-tribromomethyl)-4-chlorocyclobutan-1-ones of the formula I to 2-(2',21-dibromovinyl)-cyclopropanecarboxylic acid derivatives of the formula VIII is usually carried out by the boiling point of the selected reaction medium. Particularly suitable are reaction temperatures between 40 and 120°C.

Ved overføringen av 2-(2',2',2'-tribrometyl)-4-klorcyklobutan-l-oner med formelen I til 2-(2<1>,2'-dibromvinyl)-cyklopropankar-bonsyrederivater med formelen VIII opptrer intermediært de tilsvarende 2-(2',2<1>,2<1->tribrometyl)-cyklopro<p>ankarbonsyrederiva-ter med formelen X In the transfer of 2-(2',2',2'-tribromomethyl)-4-chlorocyclobutan-1-ones of the formula I to 2-(2<1>,2'-dibromovinyl)-cyclopropanecarboxylic acid derivatives of the formula VIII occurs intermediately the corresponding 2-(2',2<1>,2<1->tribromethyl)-cyclopropanecarboxylic acid derivatives with the formula X

hvor R, R-^, R2og X har de angitte betydninger, som mellomprodukter. Disse produkter kan oppfanges når man holder reaksjons-temperaturen under 40°C og/eller anvender et underskudd av base. Disse mellomprodukter går over 40°C ved tilsetning av ytterligere base under HX-avspaltning over i de tilsvarende 2-(2',2'-dibromvinyl)-cyklopropankarbonsyrederivater med formelen VIII. where R, R-^, R 2 and X have the indicated meanings, as intermediates. These products can be collected when keeping the reaction temperature below 40°C and/or using a deficit of base. These intermediates pass above 40°C upon addition of further base during HX cleavage into the corresponding 2-(2',2'-dibromovinyl)-cyclopropanecarboxylic acid derivatives of the formula VIII.

2-(2 *,21,2'-tribrometyl)-cyklopropankarbonsyrederivatene med formelen X kan også fremstilles ved bestråling med UV-lys, eventuelt under tilsetning av vanlige sensibilisatorer (f.eks. ketoner, som aceton, cykloheksanon, benzofenon, acetofenon og høy-ere alkylarylketoner, tioxanton, etc.) i nærvær av hydroksylgruppeholdige reagenser, som samtidig kan tjene som løsnings-middel, fotokjemisk ut fra 2-(2<1>,2',2<1>,-tribrometyl)-4-klor-cyklbbutan-l-oner med formelen I. Hydroksylgruppeholdige reagenser er f.eks. alkanoler, som metanol, etanol etc. og frem for alt vann. The 2-(2*,21,2'-tribromethyl)-cyclopropanecarboxylic acid derivatives of the formula X can also be prepared by irradiation with UV light, optionally with 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 can simultaneously serve as solvents, photochemically from 2-(2<1>,2',2<1>,-tribromethyl)-4- chloro-cyclobbutan-1-ones with the formula I. Reagents containing hydroxyl groups are e.g. alkanols, such as methanol, ethanol etc. and above all water.

Fremgangsmåten ifølge oppfinnelsen anskueliggjøres nærmere ved^de følgende eksempler.. The method according to the invention is illustrated in more detail by the following examples.

l l

I EKSEMPEL IN EXAMPLE

a) , Fremstilling av 4, 4, 4- tribromsmørsyreklorid 324,3 g (1,0 mol) 4,4,4-tribromsmørsyre oppvarmes med 600 g a), Preparation of 4, 4, 4-tribromobutyric acid chloride 324.3 g (1.0 mol) 4,4,4-tribromobutyric acid is heated with 600 g

tionylklorid og 1 ml dimetylformamid først i 2 timer ved 40°C og deretter i 3 timer ved 75°C. Deretter avdestilleres det overskytende tionylklorid og resten rektifiseres i høyvakuum. Man får 326,0 g (95% av teoretisk utbytte) 4,4,4-tribromsmør-syreklorid med kokepunkt 71 til 73°C / 0,05 Torr. thionyl chloride and 1 ml of dimethylformamide first for 2 hours at 40°C and then for 3 hours at 75°C. The excess thionyl chloride is then distilled off and the residue is rectified in a high vacuum. 326.0 g (95% of theoretical yield) of 4,4,4-tribromobutyric acid chloride with boiling point 71 to 73°C / 0.05 Torr is obtained.

b) Fremstilling av 2- klor- 4, 4, 4- tribromsmørsyreklorid 343,2 g (1,0 mol) 4,4,4-tribromsmørsyreklorid løses i 600 g b) Preparation of 2-chloro-4,4,4-tribromobutyric acid chloride Dissolve 343.2 g (1.0 mol) of 4,4,4-tribromobutyric acid chloride in 600 g

tionylklorid og blandes ved 60°C under samtidig belysning med en kvikksølv-høytrykkslampe porsjonsvis med 266,0 g (2,0 mol) N-klorsuccinimid. Etter avsluttet tilsetning av N-klorsuccini-midet røres den erholdte blanding 5 timer ved 60°C under belysning. Derpå avdestilleres tionylkloridet og resten rektifiseres i høyvakuum. Man får 309,7 g (82% av det teoretiske) 2-klor-4,4,4-tribromsmørsyreklorid med kokepunkt 59 til 63°C/ 0,05 Torr. thionyl chloride and mixed at 60°C under simultaneous illumination with a mercury high-pressure lamp in portions with 266.0 g (2.0 mol) of N-chlorosuccinimide. After completion of the addition of the N-chlorosuccinimid, the resulting mixture is stirred for 5 hours at 60°C under illumination. The thionyl chloride is then distilled off and the residue is rectified under high vacuum. 309.7 g (82% of the theoretical) of 2-chloro-4,4,4-tribromobutyric acid chloride with a boiling point of 59 to 63°C/ 0.05 Torr are obtained.

c) Fremstilling av 2-( 2', 2', 2'- tribrometyl)- 2- klor- 3, 3- di-me ty1cyk1obut an- 1-o n c) Preparation of 2-(2', 2', 2'-tribromethyl)-2-chloro-3,3-di-methy1cyclobutan-1-one

I en autoklav anbringes 90,6 g (0,24 mol) 2-klor-4,4,4-tri-bromsmørsyreklorid i 360 ml cykloheksan og 134 g (2,4 mol) isobutylen presses inn. Deretter tilpumpes ved 65°C i 4 timer en løsning av 24,2 g (0,24 mol) trietylamin i 120 ml cykloheksan. Etter avsluttet tilsetning av trietylaminløsningen holdes reaksjonsblandingen ytterligere 3 timer ved 65°C. Derpå frafiltre-res det dannete trietylaminohydroklorid og løsningsmidlet avdestilleres. Resten løses i en løsningsmiddelblanding bestående av like deler toluen og heksan og filtreres på kiselgel. Etter avdampning av løsningsmidlet får man ut av filtratet 51,4 g (54 % av det teoretiske utbytte) 2-(2',2',21-tribrometyl)-2-klor-3,3-dimetylcyklobutan-l-on med smeltepunkt 95 til 97°C. IR-spektrum (CC14) i cm"<1>: 1800 (CO). In an autoclave, 90.6 g (0.24 mol) of 2-chloro-4,4,4-tribromobutyric acid chloride are placed in 360 ml of cyclohexane and 134 g (2.4 mol) of isobutylene is pressed in. A solution of 24.2 g (0.24 mol) of triethylamine in 120 ml of cyclohexane is then pumped in at 65°C for 4 hours. After the addition of the triethylamine solution is finished, the reaction mixture is kept for a further 3 hours at 65°C. The formed triethylaminohydrochloride is then filtered off and the solvent is distilled off. The residue is dissolved in a solvent mixture consisting of equal parts toluene and hexane and filtered on silica gel. After evaporation of the solvent, 51.4 g (54% of the theoretical yield) of 2-(2',2',21-tribromomethyl)-2-chloro-3,3-dimethylcyclobutan-1-one with melting point 95 to 97°C. IR spectrum (CC14) in cm"<1>: 1800 (CO).

■'■H-NMR-spektrum (100 MHz, CDC13) i ppm: 1,39 og 1,41 (ls; ■'■H-NMR spectrum (100 MHz, CDCl 3 ) in ppm: 1.39 and 1.41 (ls;

3H) ; 2,86-3,22 (m; 2H) 3,55-4,15 (m, 2H) . 3H); 2.86-3.22 (m; 2H) 3.55-4.15 (m, 2H).

i ' d) Fremstilling av 2- ( 2 ' , 2 ', 2 '- tribrometyl)- 3 , 3- dimetyl- 4- i 'd) Preparation of 2-(2',2',2'-tribromethyl)-3,3-dimethyl-4-

klorcykTobutan- l- on chlorocycloTobutan- l- one

I 220 ml absolutt etanol løses etter metning med hydrogenklorid 22,8 g (0,054 mol) 2-(2•,2',2<1->tribrometyl)-2-klor-3,3-di-metylcyklobutan-l-on. Den erholdte løsning røres 5 timer ved 80°C. Derpå konsentreres reaksjonsblandingen på rotasjonsfor-damper til ca. 1/3 av det opprinnelige volum, blandes med vann og ekstraheres med eter. E^erekstraktet vaskes først med mettet koksaltlsøning, deretter med natriumbikarbonatløsning og tørkes over natriumsulfat. Resten som erholdes etter avdampningen av eteren kromatograferes på kiselgel, hvorved toluen tjener som elueringsmiddel. Etter forening og inndampning av. de rene frak-sjonene får man 17,1 g (75 % av det teoretiske utbytte) 2-(2<1>,2<1>,2<1->tribrometyl)-3,3-dimetyl-4-klorcyklobutan-l-on med After saturation with hydrogen chloride, 22.8 g (0.054 mol) of 2-(2•,2',2<1->tribromethyl)-2-chloro-3,3-dimethylcyclobutan-1-one are dissolved in 220 ml of absolute ethanol . The resulting solution is stirred for 5 hours at 80°C. The reaction mixture is then concentrated on a rotary evaporator to approx. 1/3 of the original volume, mixed with water and extracted with ether. The egg extract is first washed with saturated sodium bicarbonate solution, then with sodium bicarbonate solution and dried over sodium sulfate. The residue obtained after evaporation of the ether is chromatographed on silica gel, whereby toluene serves as eluent. After union and evaporation of. the pure fractions yield 17.1 g (75% of the theoretical yield) 2-(2<1>,2<1>,2<1->tribromethyl)-3,3-dimethyl-4-chlorocyclobutane- l-on with

smeltepunkt 87-89°C. melting point 87-89°C.

IR-spektrum (CC1,) i cm"<1>: 1805 (CO), IR spectrum (CC1,) in cm"<1>: 1805 (CO),

i H-NMR-spektrum 4(100 MHz, (CDC13) i ppm: 1,14 og 1,67 (1 s; 3H); in H-NMR spectrum 4 (100 MHz, (CDCl 3 ) in ppm: 1.14 and 1.67 (1 s; 3H);

3,08 til 3,68 (m; 3H); 4,77 (d; 1H).-e) Fremstilling av 2-( 2', 2'- dibromvinyl)- 3, 3- dimetylcyklo-propan- l- karbonsyre 3.08 to 3.68 (m; 3H); 4.77 (d; 1H).-e) Preparation of 2-(2',2'-dibromovinyl)-3,3-dimethylcyclopropane-1-carboxylic acid

800 g (2 mmol) 2-(2',2<1>,2<1->tribrometyl)-3,3-dimetyl-4-klorcyklo-butan-l-on tilsettes ved 0°C 5,6 ml 5%'ig natronlut. Den erholdte blanding røres først 18 timer ved 0°C og deretter 1 time ved 80°C. Derpå vaskes reaksjonsblandingen først med dietyleter og surgjøres så under kjøling med konsentrert saltsyre og ekstraheres med dietyleter. Ekstraktet vaskes med vann, tørkes 800 g (2 mmol) 2-(2',2<1>,2<1->tribromethyl)-3,3-dimethyl-4-chlorocyclo-butan-1-one are added at 0°C 5.6 ml 5 % caustic soda. The resulting mixture is first stirred for 18 hours at 0°C and then for 1 hour at 80°C. The reaction mixture is then first washed with diethyl ether and then acidified under cooling with concentrated hydrochloric acid and extracted with diethyl ether. The extract is washed with water, dried

over magnesiumsulfat og inndampes. Man får 0,59 g (100% av det teoretiske utbytte) 2-(2',2<1->dibromvinyl)-3,3-dimetylcyklopropan-1-karbonsyre, som består av 80 vekts% cis-isomer og 20 vekts% trans-isomer. over magnesium sulfate and evaporate. 0.59 g (100% of the theoretical yield) of 2-(2',2<1->dibromovinyl)-3,3-dimethylcyclopropane-1-carboxylic acid is obtained, which consists of 80% by weight of the cis-isomer and 20% by weight % trans isomer.

IR-spektrum (CHC13) i cm"<1>: 1695 (CO). IR spectrum (CHCl 3 ) in cm"<1>: 1695 (CO).

<1>H-NMR-spektrum (100 MHz, CDCI3) i ppm: 1,25 og 1,35, samt 1,30 og i,31 (1 s; 2 CH-^-grupper av trans- og cis-forbindelsen); <1>H-NMR spectrum (100 MHz, CDCl3) in ppm: 1.25 and 1.35, as well as 1.30 and i.31 (1 s; 2 CH-^ groups of the trans and cis compound );

1,62 til 2,30 (m; 2H), 6,15 og 6,70 (1 d; intensitetsforhold 1:4, totalt integral 1H). 1.62 to 2.30 (m; 2H), 6.15 and 6.70 (1 d; intensity ratio 1:4, total integral 1H).

Claims

1. Procedure for the preparation of 2-(2',2',2<1->tribromethyl)- 4-Chlorobutan-1-ones of the formula I

where one of the residues R-^ and R2 means methyl and the other hydrogen or methyl or R1 and R2 together an alkylene group with 2 to 4 carbon atoms, characterized by reacting 2-chloro-4,4,4-tribromobutyric acid chloride with the formula II

in the presence of an organic base with an olefin of formula III

where and R2 have the meanings given under formula I, to a 2-(2',2<1>,2<1->tribromethyl)-2-chlorocyclobutan-1-one of formula IV

where R 1 and R 2 have the meanings indicated under formula I, and then this rearranges in the presence of a catalyst in a 2-(2 1,2',2'-tribromethyl)-4-chlorocyclobutan-1-one of formula I .i <!>i 2. Method according to claim 1, characterized by using an olefin of formula III, where one of the residues R-^ and R? means methyl and the other hydrogen or methyl or R1 and R2 together an alkylene group of 2 to 3 carbon atoms.

3. Method according to claim 1, characterized in that isobutylene is used as olefin with formula III.

4. Process according to claim 1, characterized in that methylenecyclopropane is used as olefin of formula III.

5. Process according to claim 1, characterized in that the reaction is carried out of the 2-chloro-4,4,4-tribromobutyric acid chloride of formula II with an olefin of formula III in the presence of pyridine or a trialkylamine with 1 to 4 carbon atoms in each alkyl group and in the presence of an inert organic solvent.

6. Process according to claim 1, characterized in that the reaction of the 2-chloro-4,4,4-tribromobutyric acid chloride of formula II is carried out with an olefin of formula III in the presence of triethylamine.

7. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(21,21,21-tribromethyl)-2-chlorocyclobutan-1-one of formula IV in a 2-(2',21, 2*-tribromethyl)-4-chlorocyclobutan-1-one of formula I uses an inorganic or organic protonic acid.

8. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2',2'-tribromethyl)-2-chlorocyclobutan-1-one of formula IV in a 2-(2<1> ,2',2<1->tribromethyl)-4-chlorocyclobutan-1-one of formula I uses a hydrohalic acid.

9. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2- : i ! . (2',21,2'-tribromethyl)-2-chlorocyclobutan-1-ori of formula IV in a 2-(2',2',2'-tribromethyl)-4-chlorocyclobutan-1-one of formula I uses an organic base.

10. Process according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2',2'-tribromethyl)-2-chlorocyclobutan-1-one of formula IV in a 2-(2',2 (',2'-tribromethyl)-4-chlorocyclobutan-1-one of formula I uses an amine with the formula

where alkyl with 1 to 8 carbon atoms, cycloalkyl with 5 to 6 carbon atoms, benzyl or phenyl, and Q 2 and Q 3 independently of each other hydrogen or alkyl with 1 to 8 carbon atoms.

11. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2',2'-tribromethyl)-2-chlorocyclobutan-1-one of formula IV in a 2-(2<1> ,2',2'-tribromethyl)-4-chlorocyclobutan-1-one of formula I uses salts of protonic acids with ammonia, nitrogen-containing organic bases or quaternary ammonium salts.

12. Method according to claim 1, characterized in that as a catalyst for the rearrangement of a 2-(2',2<1>,2'-tribromethyl)-2-chlorocyclobutan-1-one with the formula IV in a 2-(2' ,2',2'-tribromethyl)-4-chlorocyclobutan-1-one of formula I employs a salt of a hydrohalic acid with an aliphatic, cycloaliphatic, araliphatic or aromatic, primary, secondary or tertiary amine or a heterocyclic nitrogen base .

13. Process according to claim 1, characterized in that as catalyst for the rearrangement of a 2-(2',2',2'-tribromethyl)-2-chlorocyclobutan-1-one of formula IV in a 2-(2',2 ',2'-tribromethyl)-4-chlorocyclobutan-1-one of formula I uses a salt of the formula where M means fluorine, bromine or iodine, especially chlorine, Q4hydrogen, alkyl of 1 to 18 carbon atoms, cyclohexyl, benzyl, phenyl or naphthyl and , Qg and Qy are independently hydrogen or alkyl of 1 to 18 carbon atoms, or an N-alkylpyridium halide of 1 to 18 carbon atoms in the alkyl group.

14. Method according to claim 1, characterized in that the rearrangement of a 2-(2',2<1>,2<1->tribromoethyl)-2-chlorocyclobutan-1-one with the formula IV is carried out in a 2-( 2',2',2l<->tribromethyl)-4-chlorocyclobutan-1-one of formula I at temperatures between 80 and 130°C.

15. Process according to claim 1, characterized in that the rearrangement of a 2-(2',2',2'-tribromoethyl)-2-chlorocyclobutan-1-one of formula IV is carried out in a 2-(2<1> ,2',2'-tribromethyl)-4-chlorocyclobutan-1-one of the formula I in the smelting at a temperature between 80 and 130°C in the presence of a trialkylamine with 1 to 8 carbon atoms in each alkyl group or a tetraalkyl- ammonium halide with 1 to 18 carbon atoms in the alkyl groups.

16. Process according to claim 1, characterized in that the rearrangement of a 2-(2',2<1>,2<1->tribromoethyl)-2-chlorocyclobutan-1-one with the formula IV is carried out in a 2-( 2',2',2'-tribromethyl)-4-chlorocyclobutan-1-one of formula I in the presence of an inert solvent.

17. Process according to claim 1, characterized in that the rearrangement of a 2-(2',2<1>,2<1->tribromoethyl)-2-chlorocyclobutan-1-one with the formula IV is carried out in a 2-( 2',2',2'-tribromethyl)-4-chlorocyclobutan-1-one of the 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.

18. 2-chloro-4,4,4-tribromobutyric acid chloride of the formula II

19. 2-(2',2',2'-tribromomethyl)-2-chlorocyclobutan-1-ones of the formula IV

where one of the radicals R-^ and R2 means methyl and the other hydrogen or methyl or R-, and R- together the alkylene with 2 to 4 carbon atoms.

20. 2-(2',22<1->tribromethyl)-4-chlorocyclobutan-1-ones of the formula I

where one of the radicals R-^ and R 2 means methyl and the other hydrogen or methyl or R-^ and R 2 together the alkylene with 2 to 4 carbon atoms.

21. Use of 2-(2<1>,2',2<1->tribromethyl)-4-chlorocyclobutan-1-ones of the formula I

where one of the radicals R-1 and R2 is methyl and the other hydrogen '! or methyl or R₂ and R₂ together the alkylene of 2 to 4 carbon atoms, for the preparation of compounds of the formula VIII

where one of the residues R-^ and R2 is methyl and the other is hydrogen or methyl or R-^ and R2 together are alkyl with 2 to 4 carbon atoms, X is chlorine or bromine, and R stands for hydrogen, alkyl with

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 phenylmercapto, R^hydrogen or an alkyl group of 1 to 4 carbon atoms and Rg hydrogen, cyano or ethynyl, or, when one of the radicals R-^ and R 2 is methyl and the other hydrogen or methyl, R 3 the vinyl group, R^ phenoxy and R^ hydrogen, also alkyl with 1 to 5 carbon atoms.