SE453079B - CYCLOPROPANCARBOXYLIC ACID DERIVATIVE, PROCEDURE FOR PREPARING THEREOF, INSECTICIDIC AND / OR ACARICIDIC COMPOSITION CONTAINING THESE DERIVATIVES AND USING THE DERIVATE OR COMPOSITION - Google Patents

Description

453 079 * Compounds of formula I containing two asymmetry centers in the cyclopropane ring of the acid residue and a third asymmetry center in the alcohol residue give rise to eight possible isomers. In general, there is a superior pesticidal activity of the compounds with cis-configuration around the cyclopropane ring, as indicated by Itaya et al in "Synthetic Pyrethroids", ACS Symposium Series 42, pp. 45-54, and the isomer which has the greatest pesticidal activity is generally the isomer conveniently referred to as the lRcisS isomer, where lRcis denotes the configuration in the acid residue and S denotes the configuration in the alcohol residue, as stated by Elliott §t_al in Nature g§§ (1974) 710-711.

Attempts to prepare separate IRcisS isomers are based either on synthesis pathways which in themselves yield intermediates containing cyclopropanecarboxylic acid residue with exclusive IRcis configuration, or on a synthesis pathway which comprises an optical cleavage step for the purpose of separating IRcis compounds from IRcis compounds associations. Esterification of an IRcis intermediate to produce a derivative of formula I above results in the preparation of a mixture of IRcisR and IRcisS end products. Separation of these end products is possible by physical methods, at least theoretically, since the 1RcisR and 1RcisS compounds are not enantiomers. Although it is relatively easy to achieve such a separation of 1RcisR- and 1RcisS- 1 and R2 are both bromine atoms, compounds have been found when R is more difficult and costly in other cases, for example when R1 and R2 are both chlorine atoms.

We have now surprisingly discovered a new compound which, by weight, contains up to four times as much of the pesticidically most active (IRcisS-) isomer of a compound of formula I compared to a compound containing equal amounts of all eight isomers of formula I. This new compound has the advantage that it can be easily and relatively inexpensively prepared by a synthetic route which does not involve any asymmetric synthetic step or optical cleavage step. The present invention relates to a compound of the formula 1 - RH cH = c <o Ra im C33 co - o _ c cH H (I) 3 wherein R and R are both chlorine atoms, in the form of a 1: 1 mixture The 1RcisS and 1ScisR isomers are substantially free of the 1ScisS and 1RcisR isomers.

According to a preferred embodiment of the invention there is provided a compound comprising a 1: 1 mixture of the 1RcisS and 1ScisR isomers of Oecyano-3-phenoxybenzyl 3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate in the form of a crystalline solid with a melting point of at least 75 ° C. The melting point is advantageously at least 80 ° C and is preferably in the range 84-87 ° C.

The compounds of the invention may be prepared by a process which comprises contacting a mixture of the 1RcisS, 1ScisS, 1RcisR and 1ScisR isomers of a compound of formula I with a solvent of the type indicated below and separating a 1 : 1 mixture of the 1RcisS and 1ScisR isomers substantially free of the 1RcisR and 1ScísS isomers as a crystalline solid from a solution of the compound of formula I containing the 1ScisS and 1RcisR isomers.

The process can be conveniently carried out by cooling a solution of the mixture of the 1RcisS, 1ScisS, 1RcisR and 1ScisR isomers. Alternatively, the process can be carried out, at least in some cases, by contacting the mixture of the 1RcisS, 1ScisS-, 1RcisR and 1ScisR isomers with the solvent at or below ambient temperature and separating the resulting solid crystalline 1: 1 mixture. of the 1RcisS and 1ScisR isomers from the resulting solution, which contains the 1ScisS and 1RcisR isomers.

The solvent used is one in which the 1RcisS / 1ScisR enantiomer pair is significantly less soluble than the 1ScisS / 1RcisR enantiomer pair.

The solvent is therefore selected from the group consisting of liquid lower alkanes having up to 8 carbon atoms, for example pentane; petroleum ethers from 30/50 petroleum ether to 100/120 petroleum ether, preferably 40/60 or 60/80 petroleum ether, and liquid C 1-4 alkanols such as isopropanol.

Crystallization of the 1RcisS- / 1ScisR-enantiomer pairs can be accomplished at a temperature in the range of -50 ° C to 20 ° C, preferably in the range of 00-1000, depending on the concentrations of the various isomers present.

Separation and recovery of the crystalline compound of the invention from the supernatant solution containing the 1ScisS and 1RcisR isomers can be performed by such methods as filtration, centrifugation and decantation.

The solution of the compound of formula I, which solution contains the 1ScisS and 1RcisR isomers, is a useful raw material for the preparation of further amounts of the compound of the invention. It has further been found that upon treatment with a suitable base a racemization can take place at the 01 carbon atom of the alcohol residue of the compound of formula I under suitable conditions, so that a proportion of the 1ScisS and 1RcisR isomers in the solution can is converted to the 1ScisR res 455 079. respective 1RcisS isomers, and further amounts of the compound of the invention can be isolated in the manner described above.

The preferred process of the invention thus involves treating the solution of the compound of formula I, which solution contains the 1ScisS and 1RcisR isomers, with a base and separating from the solution a 1: 1 mixture of the 1RcisS and 1ScisR isomers under or after treatment with the base.

If in the preferred process of the invention the mixture of the 1RcisS, 1ScisS, 1RcisR and 1ScisR isomers is completely dissolved in the solvent and the resulting solution contains equal amounts of all four cis - isomers, at least a portion of 1Rcis is separated and the 1ScisR - isomers from the solution in the form of a 1: 1 mixture of the 1RcisS and 1ScisR isomers substantially free of the 1RcisR and 1ScisS isomers as a crystalline solid before or during the treatment with the base.

Suitable bases for use in the process of the invention include ammonia, primary, secondary and tertiary amines, alkali metal hydroxides, alkali metal carbonates, alkali metal alkoxides and basic ion exchange resins. Preferred amine bases contain one or more C 1-4 alkyl and / or benzyl groups or are alkylenediamines having up to 4 carbon atoms, for example ethylenediamine, or are heterocyclic amine bases having 5 or 6 ring atoms and containing a nitrogen atom and optionally an oxygen, sulfur or an additional nitrogen atom attached to the carbon atoms in the ring, for example pyrrolidine, morpholine or piperidine.

If desired, the preferred process according to the invention can be carried out in two separate steps, possibly in two different places. The treatment with the base can be carried out, for example, at elevated temperature, for example at a temperature in the range 200-100 ° C, preferably 60 ° -60 ° C, for rapid racemization, followed by cooling to effect crystallization of 1: 1 mixture. The formation of the 1RcisS and 1ScisR isomers as described above. If the base is present in the solution, both steps of the process can be carried out in a single reaction zone or the step of elevated temperature can be carried out in one reaction zone and the crystallization step can be carried out in another reaction zone.

However, the base may be present in solid form, for example a basic ion exchange resin of the kind marketed under the trade names Dowex and Amberlite, such as Dowex AGIX 8, Amberlite IRA 400 and Amberlite IR 45, or solid potassium carbonate and the process may be carried out under anhydrous conditions. optionally in the presence of a C 1-4 alkanol such as methanol, with the base in 1-4 a reaction zone, for example a filled column, in the case of the elevated temperature step, the solution of the isomers of the compound of formula I being transferred to another reaction zone with respect to the crystallization step.

When the base is present in a solution in the preferred process of the invention and both process steps are carried out in a single reaction zone, the treatment with the base and the crystallization of the 1: 1 mixture of the 1RcisS and 1ScisR isomers can be carried out simultaneously at a temperature in the range from -so ° to 20 ° C, preferably in the range 0 ° -2o ° c. via such a process, where the base treatment and the crystallization are carried out simultaneously, the lRcisS and lScisR isomers are continuously removed from the solution by crystallization, so that the supernatant solution is always rich in lScisS and lRcisR isomers and racemization can always possess room. Accordingly, in such a process, the starting material may be a racemic mixture of all four cis isomers of the compound of formula I, which mixture is introduced directly into the reaction zone. The lScisS and lRcisR isomers dissolve more rapidly, giving a solution rich in these isomers. Racemization then takes place and the 1: 1 mixture of the 1RcisS and 1ScisR isomers crystallizes out continuously from the solution until substantially the entire amount of 1ScisS and 1RcisR isomers has dissolved and a final equilibrium has been reached. Additional amounts of the racemic mixture of all four cis isomers may be added continuously or in separate additives during the process.

When the preferred process of the invention is not carried out with a solid phase base, it is preferred that the base comprise ammonia, a primary, secondary or tertiary amine or an alkali metal carbonate, preferably sodium or potassium carbonate, in aqueous solution.

It has been found that the rate of racemization can be increased if the solution of the 1ScisS and 1RcisR isomers of the compound of formula I is treated with the base in the presence of a C 1-4 alkanol, for example methanol. The racemization rate can also be increased if the solution is treated with the base in the presence of a phase transfer catalyst. The phase transfer catalyst is preferably a quaternary ammonium halide. The substituents in the quaternary ammonium halide are, for example, C 1-4 alkyl groups and / or benzyl groups. Preferred quaternary ammonium halides are tetrabutylammonium and benzyltriethylammonium chlorides and bromides.

The compounds of the invention contain a high proportion of the most insecticidal and / or acaricidically active isomer of the relevant compound of formula I. The invention therefore also relates to an insecticidal and / or acaricidal composition which comprises a compound of formula I according to the invention together with a suitable carrier therefor, the composition being substantially free of the 1ScisS and 1RcisR isomers of the compound of formula I. The invention further provides a method of controlling insects or mites at a site, which means applying a compound at the site of formula I according to the invention or a composition according to the invention.

A carrier in a composition according to the invention may be a solid material or a liquid comprising a material which is normally gaseous but which has been compressed into a liquid, and the carrier may be inorganic or organic and of synthetic or natural origin. The active ingredient is suitably formulated with at least one carrier for the purpose of facilitating its application to the object to be treated, which may be a plant, seed or soil, or for the purpose of facilitating storage, transport or handling.

Preferably, a composition according to the invention contains at least two carriers, of which at least one is a surfactant. The surfactant may be an emulsifier, a dispersant or a wetting agent. It can be nonionic or ionic. Pesticidal compositions are generally prepared and transported in concentrated form, which are diluted before use by the consumer. A surfactant facilitates this dilution procedure.

Any of the carriers commonly used in the preparation of pesticides may be used in the compositions of the invention and suitable examples thereof are found, for example, in British Patent Specification 1,232,930.

The composition of the invention may be prepared, for example, as a wettable powder, microcapsules, powders, granules, a solution, an emulsifiable concentrate, an emulsion, a suspension concentrate or an aerosol. The composition may have the property of releasing the active ingredient under controlled conditions or may be suitable for use as bait.

Wettable powders usually contain 25, SD or 75% by weight of the active ingredient and may contain, in addition to inert solids, 3-10% by weight of a dispersant and, if necessary, 0-10% by weight of a stabilizer, a penetrant and / or a tackifier. A powder is usually prepared as a powder concentrate having a composition similar to that of a wettable powder but without dispersants and diluted in the field with an additional solid carrier to give a composition which usually contains 0.5-10% by weight 453 079 active ingredient.

Granules are usually produced with a size of 0.15-1.68 mm and can be produced by agglomeration or impregnation techniques. In general, the granules contain 0.5-25% by weight of active ingredient and 0-10% by weight of additives, such as, for example, a stabilizer, slow release modifiers and / or binders.

Emulsifiable concentrates usually contain in addition to the solvent and if required a co-solvent 10-50% (w / v) active ingredient, 2-20% (w / v) emulsifiers and 0-20% (w / v) of other additives such as a stabilizer, a penetrant and / or a corrosion inhibitor. A suspension concentrate is a stable, non-sedimenting liquid product and usually contains 10-75% by weight of active ingredient, 0.5-15% by weight of dispersant, 0.1-10% by weight of suspending agent, for example protective colloids and thixotropic agents, and -10% by weight of other additives, for example an antifoaming agent, a corrosion inhibitor, a stabilizer, a penetrant and / or a tackifier and as a dispersing medium water or an inorganic liquid, wherein the active ingredient is substantially insoluble; Certain organic additives and / or organic salts may be dissolved in the dispersion medium in order to help prevent sedimentation or as antifreeze for water.

The aqueous dispersions and emulsions prepared by diluting a wettable powder or an emulsifiable concentrate according to the invention with water also fall within the scope of the present invention. Such dispersions and emulsions may be of the water-in-oil or oil-in-water type and may have a thick, mayonnaise-like consistency.

A composition according to the invention may also contain other ingredients, for example one or more other compounds having pesticidal, herbicidal or fungicidal properties, or attractants, for example pheromones or food ingredients for use in compositions intended for baits and traps.

The invention is further illustrated by the following working examples, in which the temperature indications refer to degrees Celsius.

Example 1 1: 1 mixture of 1RcisS and 1ScisR isomers of γ (-cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate by crystallization using isopropanol, 0 g of a racemic mixture of the cis-isomers of α (-cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate was dissolved in 30 ml of isopropanol with gentle heating. The solution was cooled to 100 and allowed to stand at this temperature for 20 hours, a precipitate precipitated and separated by filtration to give 1.4 g of a solid product in the form of colorless crystals, m.p. 77 DEG-81 DEG C. Analysis by high performance liquid chromatography showed that The product was a 90% pure Izl mixture of the 1RcisS and 1ScisR isomers of the starting material, 3.2 g of the resulting solid product was recrystallized from pentane to give 2.0 g of a colorless crystalline solid, m.p. 860. This product was found by analysis by high performance liquid check chromatography be an approximately 99% pure 1: 1 mixture of the 1RcisS and 1ScisR isomers of the starting material.

Example 2 1: 1 mixture of 1RcisS and 1ScisR isomers of ° (-cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate by crystallization using 40/60 453,079 μl Betroleum ether g of a racemic mixture of the cis-isomers of α (-cyano--3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate was dissolved in 150 ml of 40/60 petroleum ether under The resulting solution was cooled to 200 DEG C. and allowed to stand at this temperature for 3 days.A colorless crystalline precipitate precipitated and was isolated by filtration.The product was obtained in a yield of 3.3 g, had a melting point of 79-810 and was found by analysis by high performance liquid chromatography to be a more than 90% pure 1: 1 mixture of the 1RcisS and 1ScisR isomers of the starting material.

Aliquots of the product obtained by the above procedure were recrystallized once, twice and three times from 40/60 petroleum ether. The resulting products, all of which were colorless, crystalline solids, had a melting point α3 -66, s4-86 ° and ss -87, respectively, and were found by analysis by high performance liquid chromatography to be 99% pure, more than 99.9% pure and 100, respectively. % pure sample of the desired isomer pair.

Example Gel 3 1: 1 mixture of 1RcisS and 1ScisR isomers ave (-cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate by treatment of a solid racemate with 40 / 604petro leumeter g of a racemic mixture of the cis-isomers of O <-cyano--3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate was stirred with 75 ml of 40/60 petroleum ether for 5 days at Filtration gave 4.1 g of colorless crystals, m.p. 81.5-830, and the product was found by analysis by high performance liquid chromatography to be an approximately 97% pure 1: 1 mixture of the 1RcisS and 1ScisR isomers of the 453 079 12 A comparison with the products of Examples 1-3 above shows that 1RcisS-si-cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-cyclopropanecarboxylate and the 1ScisR enantiomer both have the melting point s3-s4 °.

Example Gel 4 - 1: 1 mixture of 1RcisS and 1ScisR isomers ave (-cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate by crystallization using isopropanol as solvent 12.9 g of a racemic mixture of the cis-isomers avo {-cyano--3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate were dissolved in 52 ml of isopropanol at 200 and 2 .0 ml of a 0.880 M solution of ammonia in water was added with stirring. After stirring at 20 ° for 21 hours, the reaction mixture was cooled and stirred at 0-50 for a further 4 hours. The precipitated precipitate was filtered off and washed with 5 ml. isopropanol at 50 and with 15 ml of 60/80 petroleum ether to give 5.1 g of a solid product in the form of colorless crystals, m.p. 77 DEG-81 DEG C. Analysis by high performance liquid chromatography showed that the product was a 90% pure 1: 1 mixture of the 1RcisS and 1ScisR isomers of the Ht * starting material A similar analysis of the filtrate showed that the ratio of the concentration of the 1ScisS and 1RcisR - isomers to the concentration of the 1RcisS and 1ScisR isomers was about 3: 2.

The filtrate and washings from the above procedure were concentrated, the resulting material was dissolved in 30 ml of isopropanol and 2.0 ml of a 0.880 solution of ammonia in aqueous V14 F! 453,079 was added with stirring, after which the above process steps were repeated to obtain an additional 2.1 g of colorless crystals, m.p. 74-790, which on analysis by high performance liquid chromatography were found to be an 85% pure 1: 1 mixture. of the lRcisS and lScisR isomers of the starting material. A similar analysis of the filtrate showed that the ratio of the concentration of the 1ScisS and 1RcisR - isomers to the concentration of the 1RcisS and 1ScisR isomers was about 4: 1.

Example 5 1: 1 mixture of 1RcisS and 1ScisR isomers of β (-cyano-3-phenoxybenzyl-3-12,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate by crystallization using 40/60 petro leumeter as solvent g of a racemic mixture of the cis-isomers of q-cyano-S- -phenoxybenzyl 3- (2,2-dichlorovinyl) -2,2-dimethylcyclopropanecarboxylate was stirred with 75 ml of 40/60 petroleum ether and 1 ml of a 0.5 molar solution of sodium carbonate in a 1: 1 (v / v) mixture of water and methanol containing 10% (w / v) tetrabutylammonium bromide. The reaction mixture was stirred for 5 days at ambient temperature (200). Filtration gave 5.6 g of colorless crystals, m.p. 80-82 °, which on analysis by high performance liquid chromatography were found to be a 96% pure 1: 1 mixture of the 1RcisS and 1ScisR isomers Hv1 - the vapor material. A similar analysis of the filtrate showed that the ratio of the concentration of the 1ScisS and 1RcisR isomers to the β-csmarislRcisS and 1ScisR isomers was 3.4: 1.

Claims (12)

10 15 20 25 30 35 453 079 V: PATENT REQUIREMENTS 1. Association, k ä n n e t e c k n a d by the fact that it has. formula 1 R x ca - c <R2 O CN C33 CO - O - CH CH (I) 3 H 2 both are chlorine atoms and that it is in the form wherein R 1 and R of a 1: 1 mixture of 1R the isomers are substantially free of the 1ScisS and 1RcisR isomers. A compound according to claim 1, characterized in that it is a 1: 1 mixture of the 1RcisS and 1ScisR isomers of *; (- cyano-3-phenoxybenzyl-3- (2,2-dichlorovinyl) -2 , 2-dimethylcyclopropanecarboxylate in the form of a crystalline solid with a melting point of at least 75 ° C. A process for the preparation of a compound of the formula 1 wherein c 1 - c R of the 1RcisS and 1ScisR isomers is substantially free of the 1ScisS and 1RcisR isomers, characterized in that a mixture of 1RcisS, 1ScisS, 1RcisR and 1ScisR the isomers of a compound of formula I in contact with a solvent selected from the group consisting of liquid lower alkanes having up to 8 carbon atoms, petroleum ethers from 30/50 petroleum ether to 100/120 petroleum ether and liquid C 1-4 alkanols and separates a 1: 1 mixture of the 1RcisS and 1ScisR isomers substantially free of the 1RcisR and 1ScisS isomers as a crystalline solid from a solution of the compound of formula I, which solution contains 1ScisS and 1RcisR the isomers. 4. A process according to claim 3, characterized in that a solution of the mixture of the 1RcisS, 1ScisS, 1RcisR and 1ScisR isomers is cooled. 5. A process according to claim 3, characterized in that the mixture of the 1RcisS, 1ScisS, 1RcisR and 1ScisR isomers is contacted with the solvent at or below ambient temperature and the resulting solid crystalline 1: 1 is separated. the mixture of the 1RcisS and 1ScisR isomers from the resulting solution, which is rich in 1ScisS and 1RcisR isomers. 6. A process according to any one of claims 3 to 5, characterized in that the solution of the compound of formula I is further treated, which solution contains the 1ScisS and 1RcisR isomers, with a base and from the solution a 1 : 1 mixture of the 1RcisS and 1ScisR isomers substantially free of the 1RcisR and 1ScisS isomers, during or after the treatment with the base. 7. A process according to claim 6, characterized in that the solution of the isomers of the compound of formula I contains a lower liquid alkane having up to 8 carbon atoms or a liquid C 1-4 alkanol as solvent. A process according to claim 7, characterized in that the base comprises ammonia, a primary, secondary or tertiary amine or an alkali metal carbonate in aqueous solution. 9. A process according to claim 8, characterized in that the solution is treated with the base in the presence of a C 1-4 alkanol. 10. A process according to claim 8 or 9, characterized in that the solution is treated with the base in the presence of a phase transfer catalyst. 11. An insecticidal and / or acaricidal composition, characterized in that it comprises as active component a compound of the formula R 1 n CE _ c / 112 ° ï 'en co _ o - about 3 (I) cxa x 1 and R 2 are both chlorine atoms, in the form of a 1: 1 mixture wherein R of the 1RcisS and 1ScisR isomers is substantially free of the 1ScisS and 1RcisR isomers, together with a suitable carrier therefor. Use of a compound of the formula / R 1 H cn - c \ 32 o (lm C83 co - o - cn '(I) cH H m 453 079 I mixture of the 1RcisS and 1ScisR isomers substantially free of the 1ScisS and 1RcisR isomers, or of a composition according to claim 11 for controlling insects and / or mites in one place.