PREPARATION OF ESTERS CONTAINING AN ALPHA-CYANO GROUP IN THE ALCOHOL PORTION OF THE ESTERS

Abstract: Alpha-cyano esters are prepared by reacting an acyl halide with an aldehyde in a substantially water-immiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of a tertiary amine or polyamine, cryptate, amphoteric surfactant, or acid salt of tertiary amine rate-promoting agent.

Description: PREPARATION OF ESTERS This invention relates to a process for preparing esters of carboxylic acids, more specifically, esters which contain a cyano group bonded to the alpha-carbon atom in the alcohol portion of the ester molecule. Esters with a cyano group so situated are prepared by reacting an acid with the appropriate cyanohydrin. According to U.S. 3,835,176, the reaction can also be effected by treating an acyl halide with a mixture of the appropriate aldehyde and aqueous sodium or potassium cyanide, optionally in an aprotic solvent. It is disclosed, for example, that 3-phenoxy-a-cyanobenzyl chrysanthemate is prepared in 64% yield by reacting chrysanthemoyl chloride, 3-phenoxybenzaldehyde, and an aqueous solution of sodium cyanide at OOC for 1 hour. Were it possible to shorten the reaction time and increase the yield, producing this and other alpha-cyano esters by reacting an acyl halide with an aldehyde and a cyanide would be of great commercial interest. Insecticidal alpha-cyano esters whose preparations would be facilitated include a-cyano-3-phenoxybenzyl 3-(2,2 dichloroethenyl)-2,2-dimethylcyclopropanecarbozXylate and a -cyano-3-phenoxybenzyl 3- (2,2-dibromoethenyl )-2,2 -dimethylcyclopropanecarboxylate. Other insecticidal alpha-cyano esters of particular interest area-cyano-3- phenoxybenzyl 3-(2-chloro-3,3,3-trifluoropropenyl)2,2- dimethylcyclopropanecarboxylate, a-cyano-3-phenoxybenzyl 2,2,3 ,3-tetramethylcyclopropanecarboxylate, a-cyano3-phenoxybenzyl 2- (4-chlorophenyl)-3-methylbutanoate, cyano(3-phenoxyphenyl)methyl 4-difluoromethoxy- a -(1methylethyl)benzeneacetate, cyano(4-fluoro-3-phenoxyphenyl)methyl 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate, cyano ( 6-phenoxypyrid-2-yl )methyl 3- (2, 2-dichloroethenyl )-2 , 2-dimethylcyclopropanecarbox- ylate, and cyano(3-phenoxyphenyl)methyl 2- [ (2-chloro-4- trifluoromethylphenyl ) amino] -3-methylbutanoate, as well as cyano[3-(4-halophenoxy)phenyl]methyl 3-(2,2-dichloro ethenyl)-2,2-dimethylcyclopropanecarboxylates, wherein halo is fluorine, chlorine or bromine. One advantage of this invention is that it provides a process for making alpha-cyano esters in very high yield in a short time. Another advantage of this invention is that it provides an esterification process whose product does not require lengthy and expensive purification. Accordingly, this invention provides a process to prepare an alpha-cyano ester by reacting an acyl halide with an aldehyde in a mixture of substantially waterimmiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of a catalytic amount of rate-promoting agent selected from tertiary amines, polyamines, cryptates, amphoteric surfactants, and acid-salts of tertiary amines. Either the acyl halide or the aldehyde may exhibit optical or geometric isomerism, which is not affected by the reaction. In a preferred embodiment, there is provided a process for preparing an insecticidal a-cyano-3-phenoxybenzyl ester of the formula EMI2.1 wherein R is selected from 3-(2,2-dichloroethenyl)-2,2- dimethylcyclopropyl, 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropyl, 3-(2-chloro-3,3,3-trifluoropropenyl)-2,2- dimethylcyclopropyl, 2,2,3,3-tetramethylcyclopropyl, 1-(4-chlorophenyl)-2-methylpropyl, 1- (4-difluoromethoxy- phenyl )-2-methylpropyl, and 1-[-(2-chloro-4-trifluoromethyl)amino]-2-methylpropyl and R1 is selected from 3-phenoxyphenyl, 4-fluoro- (3-phenoxy)phenyl, 3-(4-halo- phenoxy)phenyl, and 6-phenoxy-2-pyridyl which comprises reacting an acyl halide of the formula EMI3.1 wherein X is chlorine or bromine and R is as defined above with 3-phenoxybenzaldehyde, 4-fluoro-3-phenoxybenzaldehyde, a 3-(4-halophenoxy)benzaldehyde, or 6-phenoxy-2-pyridylcarboxaldehyde in a mixture of substantially water-immiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of a catalytic amount of rate-promoting agent selected from tertiary polyamines, cryptates, amphoteric surfactants selected from aminoalkylsulfonic acids, and acid salts of tertiary amines. The process of this invention is especially effective in producing a high yield of insecticidal a-cyano 3-phenoxybenzyl esters in a short time when the ratepromoting agent is a tertiary polyamine or crypt ate and R is 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropyl, 3-(2',2-dibromoethenyl)-2,2-dimethylcyclopropyl, or 3-(2-chloro-3,3,3-trifluoropropenyl)-2,2-dimethylcyclopropyl, or when the rate-promoting agent is an amphoteric surfactant selected from aminoalkylsulfonic acids and R is 3-(2,2-dichloroethenyl)-2,2-dimethylcyclo -propyl or 4-(4-chlorophenyl)-2-methylpropyi, or when the rate-promoting agent is an acid salt of a tertiary amine and R is 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropyl, 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropyl, or 3-(2 chloro-3,3,3-trifluoropropenyl)-2,2-dimethylcyclopropyl. Outstanding results are obtained when R is 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropyl. Although the process of this invention is especially advantageous when R is selected from the groups named above, the process is also effective in producing other alpha-cyano esters wherein R is an aliphatic or aromatic group, which may optionally contain various substituents. Although the process of this invention is preferably employed to produce a-cyano-3-phenoxybenzyl esters by using 3-phenoxybenzaldehyde as a reactant, the process is equally suited to the production of other alpha-cyano esters by varying the type of aldehyde employed in the process. Various aprotic solvents which are substantially water-immiscible may be used in the process. Any alkyl, haloalkyl, aryl, haloaryl, aralkyl, haloaralkyl, or cyclic hydrocarbon, provided that it is a liquid at temperatures between about O0C and 50iC and forms a discrete second phase when mixed with water, may be used. Such solvents include iso-hexane, 3-methylpentane, 2,3-dimethylbutane, 2,2-dimethylbutane, n-heptane, n-octane, petroleum ether, ligroin, n-propyl bromide, n-propyl iodide, n-butyl chloride, n-butyl bromide, n-pentyl chloride, n-pentyl bromide, diethyl ether, dipropyl ether, dibutyl ether, benzene, toluene, and xylene, for example. Among these solvents, n-heptane is preferred because it is readily available and inexpensive. A number of water-soluble cyanide salts may be used; for example, the salt may be an alkali metal cyanide such as lithium, sodium, potassium, rubidium, or cesium cyanide, or mixtures thereof. Among these, sodium cyanide generally is preferred. However, when it is desired to use certain cryptates as rate-promoting agents, it may be desirable to substitute lithium or potassium cyanide as described below. The cyanide salt is dissolved in water, the amount of water employed being relatively small, but preferably sufficient to keep all of the cyanide salt in solution under the reaction conditions. In the case that the salt is sodium cyanide, the preferred molar ratio of water to sodium cyanide is between about 3.5 and 6, preferably about 4.5. The process of this invention is conducted in the presence of a catalytic amount of rate-promoting agent selected from tertiary amines, polyamines, cryptates, amphoteric surfactants, and acid salts of tertiary amines. For purposes of this invention, a catalytic amount of rate-promoting agent is in the range 1-5 mole percent based on aldehyde, advantageously about 2 mole percent. The rate-promoting agent may be a tertiary amine or polyamine, a tertiary polyamine being a compound containing more than one tertiary amino nitrogen atom. Particularly desirable tertiary polyamines are linear tertiary polyamines of the formula EMI5.1 wherein Y is -(CH2)k- with k being 1-6, r C3-C7 cyclo- alkane, C2-C6 alkenyl, or C2-C6 alkynyl; z is 1 or 2, and when z is 1, m and n are 0 or independently 1-6, and when m and n are 0, R1, R2, R3, and R4 are hydrocarbon groups, and R1 may be joined with R2, and R3 may be joined with R4 to form a ring containing the N atom to which both are joined, and when m is 1-6 and n is 0, R1 and R3 are absent, and R2 and R4 are hydrocarbon groups, and when both m and n are at least 1, R2 and R4 are absent; and when z is 2, m and n are 0, R1 and R3 are hydrocarbon groups and R2 and R4 are absent. Particularly useful linear tertiary polyamines within the aforesaid description are 2,4-dimethyl-2,4diazapentane, 2,5-dimethyl-2,5-diazahexane, 1,1 '-(1,2- ethanediyl)bis[piperidine], N,N,N' ,N'-tetramethyl-1 ,2- diaminocyclohexane, 1,4-dimethyl-1,4-diazacyclohexane, diazabicyclo[2.2.2]octane, 2,6-dimethyl-2,6-diazaheptane, 2,7-dimethyl-2,7-diazaoctane, 2,7-dimethyl-2,7-diaza-4octene, 2,7-dimdthyl-2;7-diaza-4-octyne, 2,9-dimethyl2,9-diazadecane, and 2,5,8,11-tetramethyl-2,5,8, 11tetraazadodecane. Among these compounds, diazabicyclo [2.2.2loctane, 2,6-dimethyl-2,6-diazaheptane, 2,7 dimethyl-2,7-diazaoctane, and 2,5,8,11-tetramethyl2,5,8,11-tetrazadecane are preferred, and diazabicyclo [2.2.2]octane is especially attractive. Macrocyclic tertiary polyamines such as 1,4,8,11 tetraazacyclotetradecane, for example, are also useful, as are sparteine and hexamethylenetetraamine. Cryptates, polyoxadiazamacrobicycles, constitute another class of rate-promoting agent useful in the practice of this invention. Cryptates of the formula EMI6.1 wherein x and y are independently 1 or 2 are especially useful. When the cyanide salt is sodium cyanide 4,7,13, 16,21-pentaoxa-1,10-diazabicyclo[8.8.5]tricosane is preferred, but when lithium cyanide is employed 4,7,13, 18-tetraoxa-1 ,10-diazabicyclo[8.5.5]eicosane should be used, and 4,7,13,16,21, 24-hexaoxy-1,1Q-diazabicyclo- [8.8.8]hexacosane is preferred when potassium cyanide is employed. Further, for purposes of this invention and wherever it appears in the specification or claims, the term "aminoalkylsulfonic acids, means compounds having the structural formula EMI6.2 wherein n is 2 or 3, and wherein R1 and R2 are substituents selected collectively to render the aminoalkyl sulfonic acids soluble in water-immiscible aprotic sol vents. Suitable substituent groups, which collectively contain hydrocarbon units, are present in the following specific aminoalkylsulfonic acids: 1 ,4-piperazinebis- ethanesulfonic acid, 4-pyridineethanesulfonic acid, 2-[N,N-di-(2-hydroxy)ethyl) aminoethanesulfonic acid, 3- (cyclohexylamino )propanesulfonic acid, 2-[4-(2-hydroxy- ethyl)piperzine-1-yl] ethanesulfonic acid, 2-(N-morpho lino)ethanesulfonic acid, N-tris(hydroxymethyl)methyl 2-aminoethanesulfonic acid, 2-(N-morpholino) propanes 2-(N-morpholino)propanesul- fonic acid, and N-tris(hydroxymethyl)methyl-2-amino- ethanesulfonic acid. Among these compounds, 1,4-piper izinebisethanesulfonic acid and 3-(cyclohexylamino) 3- (cyclohexylamino)pro- panesulfonic acid are preferred, and 3-(cyclohexylamino) propanesulfonic acid is especially effective. The tertiary amines whose acid salts are rate promoting agents contain one or more, e.g., two, nitrogen atoms. For purposes of this invention and wherever it appears in the specification or claims the term, "acid salts of tertiary amines," means products of the reac tion between a strong acid, such as HCl, HBr, H2SO41 HBF4, HClO4, or HCN and a tertiary amine or poly amine, a tertiary polyamine being a compound containing more than-one tertiary amino nitrogen atom. For purposes of this invention, a tertiary amine has the structural formula EMI7.1 wherein Ra, Rb, and R are hydrocarbon groups. c Particularly desirable tertiary polyamines within the scope of this invention are linear tertiary polyamines of the formula ' EMI8.1 wherein Y is (CH2)k with k being 1-6, C3-C7 cycloalkane, C2-C6 alkenyl, or C2-C6 alkynyl; z is 1 or 2, and when z is 1, m and n are 0 or independently 1-6, and when m and n are 0, R1, R2, R3, and R4 are hydrocarbon groups, and R1 may be joined with R2, and R3 may be joined with R4 to form a ring containing the N atom to which both are joined, and when m is 1-6 and n is 0, R1 and R3 are absent, and R2 and R4 are hydrocarbon groups, and when both m and n are at least 1, R2 and R4 are absent; and when z is 2, m and n are 0, R1 and R3 are hydrocarbon groups and R2 and R are absent. Particularly useful linear tertiary polyamines within the aforesaid description are 2,4-dimethyl-2,4diazapentane, 2,5-dimethyl-2,5-diazahexane, 1,1 '-(1,2- ethanediyl)bis[piperidinei, N,N,N',N'-tetramethyl-1,2- diaminocyclohexane, 1 ,4-dimethyl-1 ,4-diazacyclohexane, diazabicyclo[2.2.2)octane, 2,6-dimethyl-2,6-diazaheptane, 2,7-dimetPl-2,7-diazaoctane, 2,7-dimethyl-2,7-diaza-4octene, 2,7-dimethyl-2,7-diaza-4-octyne, 2,9-dimethyl2,9-diazadecane, and 2,5,8,11-tetramethyl-2,5,8,11-tetraazadodecane. Among these compounds, diazabicyclo[2.2.2]- octane, 2,6-dimethyl-2,6-diazaheptane, 2,7-dimethyl-2,7diazaoctane, and 2,5,8,11-tetramethyl-2,5,8,11-tetrazadecane are preferred, and diazabicyclo[2.2.21octane is especially attractive. Macrocyclic tertiary polyamines such as 1, 4, 8, 11-tetraazacyclotetradecane, for example, are also useful, as are sparteine and hexamethylenetetraamine. Although other acid salts are effective, it is preferred that the salt be a hydrohalide, especially a hydrochloride. Acid salts of tertiary amines which may be employed in this invention include, for example, diazabicyclo[2.2.2]octane dihydrochloride, 2,7-dimethyl2,7-diazaoctane dihydrochloride, 2,3,4,6,7,8,9,10-octa- hydropyrimido[1,2-a]azepine hydrochloride, and quinuclidine hydrochloride. The process of this invention is carried out between approximately equimolar amounts of the acyl halide, preferably the acyl chloride, aldehyde and aqueous solution of cyanide salt in the water-immiscible aprotic solvent, but slight excesses of the acyl halide and cyanide salt are typically used. The acyl halide may be added last, preferably dropwise, to the stirred reaction mixture, but it is preferred to add a solution containing aldehyde and acyl halide to a stirred mixture of aqueous cyanide salt and water-immiscible aprotic solvent. Although the reaction can be carried out over a wide temperature range, the range 0µC-50eC is satisfactory in most cases, and it is preferred to carry out the reaction at room temperature, since neither external heating nor cooling are then required. The process will be understood more readily by reference to the following Examples, which illustrate it. Temperatures are in degrees Celsius. The reactions exemplified were, in many cases, monitored by gas liquid partition chromatography (glpc), and the time required for disappearance of the limiting reagent after beginning addition of the acyl halide was determined, together with the amount of alpha-cyano ester produced at that time. Example 1 Preparation of a-cyano-3-phenoxybenzyl 3- (2 ,2-di chLsroethenyl)-2,2-dimethylcyclopropanecarboxylate A. Using diazabicyclo[2.2.2]octane (1) A flask was charged with 3-phenoxybenzaldehyde (1.98 g, 10.0 mmole), sodium cyanide (0.59 g, 12 mmole), 20 ml n-heptane, 1 ml water, and diazabicyclo[2.2.2]- octane (0.022 g, 0.2 mmole). This mixture was vigor ously stirred, and 3-(2,2-dichloroethenyl)-2,2-dimethyl cyclopropanecarbonyl chloride (2.38 g, 10.5 mmole) was added in one portion. Stirring was continued at room temperature for one hour, at which time glpc indicated a 94% yield of the desired alpha-cyano ester. The mixture was filtered. The filter cake was washed twice with 10 ml portions of diethyl ether. The filtrate was dried over magnesium sulfate, and the heptane was stripped under reduced pressure to yield the desired ester as a residual oil (4.10 g). Use of the optically active (1R,cis) carbonyl chloride in the aforesaid process afforded the corre sponding optically active ester in 96% yield within 1 hr. reaction time. (2) Under a dry nitrogen atmosphere a mixture of sodium cyanide (5.9 g, 0.12 mole) and 1,4-diazabicyclo t2.2.2]octane (0.22 g, 0.002 mole) in 10 grams of water was stirred at room temperature. During a one hour period a solution of 3-phenoxybenzaldehyde (20.6 g, 0.1 mole) and 3-(2,2-dichloroethenyl)-2, 2-dimethylcyclopropanecarbonyl chloride (24.1 g, 0.105 mole) in 120 ml of n-octane was added to the reaction mixture. After complete addition, the reaction mixture was stirred for one hour. - An aqueous solution containing 20% sodium carbonate was added to the reaction mixture and the total warmed to soe. The organic phase was separated and washed with water, dried over anhydrous magnesium sulfate and filtered. The solvent was removed from the filtrate under reduced pressure to yielda-cyano-3phenoxybenzyl 3-(2,2-dichloroethenyl)-2,2-dimethyl cyclopropanecarboxylate. Using 2,6-dimethyl-2,6-diazaheptane A flask was charged with a solution of 3-phenoxy benzaldehyde (1.98 g, 10 mmole) in 10 ml n-heptane. This solution was cooled to 10 , then 2,6-dimethyl-2,6diazaheptane (26 mg, 0.2 mmole), sodium cyanide (0.59 g, 12 mmole), and 1 ml water were added. 3-(2,2-Dichloro ethenyl )-2,2-dimethylcyclopropanecarbonyl chloride (2.38 g, 10.5 mmole) was then added in one portion with stirring, and the temperature of the reaction mixture was maintained at 8-12-. After 45 minutes, glpc indicated a 93% yield of the desired alpha-cyano ester. After a total of 1.25 hours, the reaction mixture was filtered. The filter cake was washed with ether, and the solvent was evaporated from the filtrate, affording the desired ester (4.3 g). C. Using 2,5,8,11-tetramethyl-2,5,8,11-tetraazado- decane A flask equipped with a stirrer, addition funnel, and an inlet for nitrogen gas was charged with sodium cyanide (0.59 g, 0.012 mole) dissolved in 1 ml water, 2,5,8,11-tetramethyl-2,5,8,1 1-tetraazadodecane (0.048 g, 0.2 mmole) in 3 ml heptane, and 3-phenoxybenzaldehyde (1.98 g, 0.01 mole) in 7 ml heptane. The reactants were mixed under a nitrogen atmosphere. 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarbonyl chloride (2.38 g, 0.0105 mole) in 10 ml heptane was added dropwise to the stirred mixture over a period of 20 minutes. Twenty minutes later, a total of 40 minutes, glpc indicated a 93% yield of the desired ester. The reaction mixture was stirred for another 40 minutes, then poured into a separatory funnel, diluted with 40 ml diethyl ether, washed once with a 1N aqueous solution of sodium hydroxide, three times with water, and once with saturated aqueous sodium chloride solution. After phase separation, the separated ethereal layer was dried over magnesium sulfate, and the solvent was evaporated, affording the ester as a pale yellow oil (4.02 g). -- D. Using 4,7,13,16,21-pentaoxa-1,10-diazabicyclo- [8.8.5]tricosane A flask was charged with 3-phenoxybenzaldehyde (1.98 g, 10 mmole), 10 ml n-heptane, 4,7,13,16,21-penta oxa-1,10-diazabicyclo[8.8.5]tricosane (66 mg, 0.2 mmole), sodium cyanide (0.59 g, 12 mmole), 1 ml water, and a solution of 3- (2,2-dichloroethenyl)-2,2-dimethyl cyclopropanecarbonyl chloride (2.38 g, 10.5 mmole) in 10 ml n-heptane. The reaction mixture was stirred, and an exotherm (to approximately 40d) was observed after 20 minutes. After 50 minutes, glpc showed a 99% yield of the desired ester. The reaction mixture was filtered, diluted with ether, dried over magnesium sulfate, and the solvent was evaporated to afford the desired ester (3.90 g). E. Using Tetramethylethylene Diamine A solution of 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarbonyl chloride (114 g, 0.315 mole) and 3-phenoxybenzaldehyde (61.9 g, 0.3 mole) in 275 ml of n-heptane was added dropwise under nitrogen in one hour to a stirred mixture of sodium cyanide (18 g, 0.36 mole), tetramethylethylene diamine (0.7 g, 0.006 mole), and 30 g of water at about 40'. After the addition, the reaction mixture was stirred for 90 minutes at about 40'. The reaction mixture was worked up as in Example 1A.(2), producing the desired ester. F. Using Tetramethyl-1,6-hexane Diamine By the method of Example 1E. above, but substituting tetramethyl-1 ,6-hexane diamine for tetramethylethylene diamine, & yano-3-phenoxybenzyl 3-(2,2-dichloroethenyl)2,2-dimethylcyclopropanecarboxylate was prepared. The preparation of a-cyano-3-phenoxybenzyl 3-(2,2 d ichloroethenyl ) -2, 2-dimethylcyclopropanecarboxylate using other tertiary amine or polyamine and cryptate rate-promoting agents under otherwise similar conditions gave the results shown in Table 1. Example 2 Preparation of a-cyano-3-phenoxybenzyl 3-(2,2-dibromo ethenyl )-2,2-dimethylcyclopropanecarboxylate using diazabicyclo[2.2.2]octane A flask was charged with 3-phenoxybenzaldehyde (1.98 g, 10.0 mmole), 10 ml n-heptane, diazabicyclo [2.2.2]octane (22 ml, 0.2 mmole), sodium cyanide (0.59 g, 12 mmole), and 1 ml water. 3-(2,2-Dibromoethenyl) 2,2-dimethylcyclopropanecarbonyl chloride (332 g, 10.5 mmole) in 10 ml n-heptane was added with stirring. After 2 hours, the reaction mixture was filtered, the filter cake was washed with 30 ml of ether, and the filtrate was dried over magnesium sulfate. The solvent was stripped, affording the desired ester as a yellow oil (4.4 g, 96% yield). Example 3 Preparation of a-cyano-3-phenoxybenzyl 3- (2-chloro-3 ,3 ,3- trifluoropropenyl)-2,2-dimethylcyclopropanecarboxylate using 2,7-dimethyl-2,7-diazaoctane A flask was charged with 3-phenoxybenzaldehyde (1.98 g, 10 mmole), 10 ml n-heptane, 2,7-dimethyl-2,7 diazaoctane (29 mg, 0.2 mmole), sodium cyanide (0.59 g, 12 mmole) and 1 ml water. 3-(2-Chloro-3,3,3-trifluoro- propenyl)-2,2-dimethylcyclopropanecarbonyl chloride (2.0 g, 10.5 mmole) dissolved in 10 ml n-heptane was then added in one portion. After 1.3 hr., the conver sion was complete. The reaction mixture was stirred for 4.5 hr, when 5 ml diethyl ether and 5 ml 1N aqueous sodium hydroxide solution were added. The resultant mixture was stirred for 1.5 hr and the two phases separated. The organic phase was washed once with iN aqueous sodium hydroxide solution, once with water, and once with a saturated aqueous sodium chloride solution, then dried over magnesium sulfate, filtered, and the solvent distilled off under reduced pressure to afford the desired ester (4.1 g, 91% yield). Example 4 Preparation of a-cyano-3-phenoxybenzyl 2,2,3,3-tetra methylcyclopropanecarboxylate using 2,6-dimethyl-2,6 d iazaheptane A flask was charged with 3-phenoxybenzaldehyde (3.16 g, 16 mmole), 10 ml n-heptane, 2,6-dimethyl-2,6 diazaheptane (26 mg, 0.2 mmole), sodium cyanide (0.94 g, 19.2 mmole) and 1 ml water. 2,2,3,3-TetramethylcyClO- propanecarbonyl chloride (2.6 g, 16.7 mmole) dissolved in 10 ml n-heptane was added next, in one portion. An exotherm (to approximately 38 ) was observed upon addition of the acid chloride. Analysis indicated a 74% yield of the desired ester in 4 hours. After cooling, the reaction mixture was filtered, diluted with diethyl ether, dried over magnesium sulfate, and distilled under reduced pressure to afford an orange residual oil. The oil was dissolved in 25 ml diethyl ether, and the resultant ethereal solution was mixed for 2 hr with a 1N aqueous sodium hydroxide solution. After phase separation, the ethereal layer was washed once with water, once with a saturated aqueous sodium chloride solution, dried over magnesium sulfate, and the solvent was distilled under reduced pressure to afford the desired ester (3.0 g). Example 5 Preparation of a-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)-3-methyl butanoate A. Using diazabicyclo[2.2.2)octane A flask was charged with 3-phenoxybenzaldehyde (1.98 g, 10 mmole), 10 ml n-heptane, diazabicyclo[2.2.2]octane (22 mg, 0.2 mmole), sodium cyanide (0.59 g, 12 mmole), and -1 ml water, and stirring was begun. 2-(4 Chlorophenyl)-3-methylbutanoyl chloride (2.42 g, 10.5 mmole) in 10 ml n-heptane was then added in one portion. The reaction mixture was stirred at room temperature for 1 hr at which time glpc indicated a 74% yield of the desired ester. Stirring was continued overnight, then the reaction mixture was filtered, diluted with diethyl ether, and the solvent was distilled under reduced pressure to afford the desired ester as the residue (4.02 g). B. Using 2,5,8,11-tetramethyl-2,5,8,11-tetraaza- dodecane A flask was charged with 3-phenoxybenzaldehyde (1.98 g, 10 mmole), 20 ml n-heptane, 2,5,8,11-tetra methyl-2,5,8,11-tetraazadodecane (0.046 g), sodium cyanide (0.59 g, 12 mmole), and 1 ml. water. With stirring, 2-(4-chlorophenyl)-3-methylbutanoyl chloride (2.42 g, 10.5 mmole) was added dropwise over a period of 6 minutes. The reaction mixture was stirred at room temperature. Analysis by glpc 2.4 hr. after the acyl chloride had been added indicated a 67.7% yield of the desired ester. Stirring was continued overnight, and the desired ester (3.4 g) was isolated as described in the preceding Example. Example 6 Preparation of a-cyano-3-phenoxybenzyl 3- (2, 2-dichloro- ethenyl ) -2, 2-dimethylcyclopropanecarboxylate A. Using 1,4-piperazinebisethanesulfonic acid as the rate-promoting agent A flask was charged with 3-phenoxybenzaldehyde (1.98 g, 10 mmole), 10 ml n-heptane, 1,4-piperazinebisethanesulfonic acid (60 mg, 0.2 mmole), sodium cyanide (0.59 g, 12 mmole), 1 ml water, and a solution of 3- (2, 2-dichloroethenyl ) -2, 2-dimethylcyclopropanecarbonyl chloride (2.38 g, 10.5 mmole) in 10 ml n-heptane. The reaction mixture was stirred for 4.5 hours (glpc indicated a 91% yield after 1 hr, 50 min), diluted with 30 ml ¯diethyl ether, then washed once with 1N aqueous sodium hydroxide solution (20 ml), once with water (20 ml), and once with a saturated aqueous sodium chloride solution (20 ml). After separation, the clear yellow ethereal solution was dried over magnesium sulfate; then the solvent was evaporated to afford the desired ester (4.05 g). B. Using 3- (cyclohexylamino)propanesulfonic acid as the rate-promoting agent (1) In the manner of Example A above, but substituting 3-(cyclohexylamino)propanesulfonic acid (44 mg, 0.2 mmole) for the 1,4-piperazinebisethanesulfonic acid, glpc indicated a 97.2% yield of the desired ester after 95 minutes and isolation afforded the desired ester (3.49 g). In a similar experiment, glpc indicated a 99% yield of the desired ester in two hours. (2) A stirred mixture of sodium cyanide (18.0 g, 0.36 mole) and 3-(cyclohexylamino)propanesulfonic acid (1.34 g, 0.006 mole) in 300 ml of water was warmed to 40'. During a one hour period, maintaining a reaction temperature of about 40', a solution of cis-3-(2,2-di chloroethenyl ) -2, 2-dimethylcyclopropanecarbonyl chloride (71.7 g, 0.315 mole) and 3-phenoxybenzaldehyde (61.9 g, 0.3 mole) in 262.2 g of n-heptane was added. The mixture was then stirred at 404 for one additional hour, after which it was washed with an aqueous solution containing 20% sodium carbonate and then with water. The organic phase was separated from the mixture and the solvent removed by distillation under reduced pressure to give a-cyano-3-phenoxybenzyl cis-3- (2,2-dichloro- ethenyl )-2 , 2-dimethylcyclopropanecarboxylate. The substitution of other rate-promoting agents under otherwise similar conditions gave the following yields (glpo) after the indicated reaction times. Rate-Promoting Reaction Agent Time Yield 2-[4-(2-hydroxyethyl)piper azine-1-yl]ethanesulfonic acid 55 min. 918 4-pyridineethanesulfonic acid 2.3 hr. 94% 2-[N,N-di-(2-hydroxy)ethyl] aminoethanesulfonic acid 3.3 hr. Example 7 Preparation of a-cyano-3-phenoxybenzyl 2- (4-chloro- phenyl)-3-methyl butanoate using 3-(cyclohexyl amino)propanesulfonic acid as the rate-promoting - agent A flask was charged with 3-(cyclohexylamino)propanesulfonic acid (42 mg), 3-phenoxybenzaldehyde (1.90 g, 9.6 mmole), sodium cyanide (0.56 g, 12 mmole), 1 ml water, and 15 ml n-heptane. 2-(4-Chlorophenyl)-3-methyl bu-tdnoyl chloride (2.34 g, 10.1 mmole) in 5 ml n-heptane was added dropwise over a period of 24 minutes to the stirred mixture. Thirty minutes after the addition was complete, a total of 54 minutes, glpc indicated a 95.6% yield of the desired ester. After stirring overnight, the reaction mixture was filtered and extracted with ether. The ether was evaporated from the extract, affording a-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)3-methyl butanoate (3.47 g). Example 8 Preparation of a-cyano-3-phenoxybenzyl 3-(2,2-dichloroethenyl)2,2-dimethylcyclopropanecarboxylate using diazabicyclo[2.2.2]octane dihydrochloride as the ratepromoting agent (1) A flask was charged with 3-phenoxybenzaldehyde (1.98 g, 10.0 mmole) 10 ml n-heptane, diazabicyclo[2.2.2] octane dihydrochloride (30 mg, 0.2 mmole), sodium cyanide (0.59 g, 12 mmole), 1 ml water, and a solution of 3- (2,2-dichloroethenyl)-2,2-dimethylcyclopropanecar bonyl chloride (2.38 g, 10.5 mmole) in 10 ml n-heptane. The reaction mixture was stirred, and after 1.5 hours glpc indicated a 96% yield of the desired ester. After a total of 1 hr., 50 min, the reaction mixture was filtered, diluted with ether, the phases were separated, the etherphase was dried over magnesium sulfate, and the solvent was evaporated to afford the desired ester (3.98 g). (2) A stirred mixture of sodium cyanide (18.1 g, 0.36 mole) and diazabicyclof2.2.2]octane dihydrochloride (1.11 g, 0.006 mole) in 30 g of water was warmed to 40-. During a one hour period a solution of 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarbonyl chloride (77.6 g, D.33 mole) and 3-phenoxybenzaldehyde (61.5 g, 0.3 mole) in 102 ml of n-heptane was added to the reaction mixture. After complete addition, the reaction mixture was stirred for 40 minutes and an additional 3.5 g (0.015 mole) of the acyl chloride added. The reaction mixture was stirred for an additional 40 minutes and then washed with 100 g of a 10% aqueous sodium carbonate solution and then water. The organic phase was separated from the mixture and the solvent removed by distillation under reduced pressure to give a-cyano-3-phenoxybenzyl 3-(2,2 dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate. The preparation of a-cyano-3-phenoxybenzyl 3-(2,2 dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate using othey rate-promoting agents under otherwise similar conditions gave the following results. Rate-Promoting Reaction Yield Agent Time 2, 7-dimethyl-2, 7-diaza- octane dihydrochloride 1.4 hr 96% 2,3,4,6,7,8,10-octahydro pyrimido[1,2-a]azepine 4 hr 99% hydrochloride quinuclidine 1.8 hr 98% hydrochloride Table 1 PREPARATION OF a-CYANO-3-PHENOXYBENZYL 3- (2, 2-DICHLORO- ETHENYL)-2 ,2-DIMETHYLCYCLOPROPANECARBOXYLATE USING OTHER TERTIARY AMINE OR POLYAMINE AND CRYPTATE RATE PROMOTING AGENTS Reaction Rate-Promoting Agent Time Yield tri-n-hexylamine 4.5 hours 82% triethylamine 2 hours 89% 2,4-dimethyl-2,4 diazapentane 24 hours 96% 2,5-dimethyl-2,5 diazahexane 0.5 hour 91% 2, 9--dimethyl-2, 9- diazadecane 1.0 hour 96% 1,1 '-(1 ,2-ethanediyl)- bis[piperidine] 1.0 hour 94% 1 ,4-dimethyl-1 ,4- diazacyclohexane 1.0 hour 86% Table 1 (Cont) N,N,N' ,N'-tetramethyl- 1,2-diaminocyclohexane 1.5 hours 96% 1,4,8,11-tetramethyl-1,4,8, 11-tetraazacyclotetradecane 1.5 hours 96% (-)-sparteine 1.3 hours 95%

Claims: Claims: 1. A process to prepare an alpha-cyano ester characterized by reacting an acyl halide with an aldehyde in a mixture of substantially water-immiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of a catalytic amount of rate-promoting agent selected from tertiary amines or polyamines, cryptates, amphoteric surfactants, and acid salts of tertiary amines. 2. A process according to claim 1 characterized in that an insecticidal a-cyano-3-phenoxybenzyl ester of the formula EMI20.1 wherein R is selected from 3-(2,2-dichloroethenyl)-2,2- dimethylcyclopropyl, 3-(2,2-dibromoethenyl)-2,2-dimethylcyclopropyl, 3-(2-chloro-3,3,3-trifluoropropenyl)-2,2- dimethylcyclopropyl, 2,2,3,3-tetramethylcyclopropyl, 1- (4-chlorophenyl )-2-methylpropyl, 1- (4-difluoromethoxy- phenyl)-2-methylpropyl, and 1- [ (2-chloro-4-trifluoro- methyl)amino]-2-methylpropyl and R1 is selected from 3-phenoxyphenyl, 4-fluoro- (3-phenoxy )phenyl, 3-(4-halo- phenoxy)phenyl, and 6-phenoxy-2-pyridyl is prepared by reacting an acyl halide of the formula EMI20.2 wherein X is chlorine or bromine and R is as defined above with 3-phenoxybenzaldehyde, 4-fluoro-3-phenoxybenzaldehyde, a 3-(4-halophenoxy)benzaldehyde, or 6-phenoxy-2-pyridylcarboxaldehyde in a mixture of substantially water-immiscible aprotic solvent and an aqueous solution of water-soluble cyanide salt in the presence of a catalytic amount of rate-promoting agent selected from tertiary amines or polyamines, cryptates, amphoteric surfactants selected from aminoalkylsulfonic acids, and acid salts of tertiary amines. 3. A process according to claim 2 characterized by using a rate-promoting agent selected from tertiary polyamines which are linear tertiary polyamines of the formula EMI21.1 wherein Y is -(CH2)k- with k being 1-6, C3-C7 cycloalkane, C2-C6 alkenyl, or C2-C6 alkynyl; z is 1 or 2, and when z is 1, m and n are 0 or independently 1-6, and when m and n are 0, R1, R2, R3, and R4 are hydrocarbon groups, and R1 may be joined with R2, and R3 may be joined with R4 to form a ring containing the N atom to which both are joined, and when m is 1-6 and n is 0, R1 and R3 are absent, and R2 and R4 are hydrocarbon groups, and when both m and n are at least 1, -R2 and R4 are absent; and when z is 2, m and n are 0, R1 and R3 are hydrocarbon groups and R2 and R4 are absent, 1 ,4,8,11-tetramethyl-1,4, 8,11-tetraazacyclotetradecane, sparteine, and cryptates. 4. The process of claim 3 characterized in that the linear tertiary polyamine is selected from 2,4-dimethyl-2,4-diazapentane, 2,5-dimethyl-2,5-diazahexane, 1,1'-(1,2-ethanediyl)-bis[piperidine], N,N,N',N'-tetramethyl-1,2-diaminocyclohexane, 1 ,4-dimethyl-1 ,4-diaza- cyclohexane, diazabicyclo[2022]octane, 2,6-dimethyl-2, 6-diazaheptane, 2,7-dimethyl-2,7-diazaoctane, 2,9-di methyl-2,9-diazadecane, and 2,5,8,1 1-tetramethyl-2,5,8, 11-tetraazadodecane. 5. The process of claim 4 characterized in that the linear tertiary polyamine is diazabicyclo[2.2.2]- octane, 2,6-dimethyl-2,6-diazaheptane, 2,7-dimethyl-2,7diazaoctane, or 2,5,8,11-tetramethyl-2,5,8,11-tetraaza- decane. 6. The process of claim 5 characterized in that the rate promoting agent is diazabicyclo[2.2.2]octane. 7. The process of claim 3 characterized in that the rate promoting agent is a cryptate of the formula EMI22.1 wherein x and y are independently 1 or 2. 8. The process of claim 7 characterized in that the cryptate is 4,7,13,16,21-pentaoxo-1 ,10-diazabicyclo- [8.8.5]tricosane. - 9. A process according to any one of claims 3-8 characterized in that R is 3-(2,2-dichloroethenyl)-2,2- dimethylcyclopropyl. 10. A process according to any one of claims 3-8 characterized in that the water-immiscible aprotic solvent is n-heptane. 11. A process according to any one of claims 3-8 characterized in that the water-soluble cyanide salt is sodium cyanide. 12. The process of claim 2 characterized in that the rate-promoting agent is an aminoalkylsulfonic acid selected from 1 ,4-piperazinebisethanesulfonic acid, 4-pyridineethanesulfonic acid, 2-[N,N-di-(2-hydroxy)- ethyl) aminoethanesulfonic acid, 3- ( cyclohexylamino)pro- panesulfonic acid, and 2-[4-(2-hydroxyethyl)piperizine- 1-yl]ethanesulfonic acid. 13. The process of claim 12 characterized in that the rate-promoting agent is selected from 1,4-piperizine bisethanesulfonic acid and 3 - ( 3- (cyclohexylamino)propane- sulfonic acid. 14. The process of claim 13 characterized in that the rate-promoting agent is 3-(cyclohexylamino)propanesulfonic acid. 15. A process according to any one of claims 12-14 characterized in that R is 3-(2,2-dichloroethenyl)-2,2- dimethylcyclopropyl or 1-(4-chlorophenyl )-2-methylpropyl. 16. A process according to any one of claims 12-14 characterized in that R is 3-(2,2-dichloroethenyl)-2,2- dimethylcyclopropyl. 17. Aprocess according to any one of claims 12-14 characterized in that the water-immiscible aprotic solvent is n-heptane. 18. A process according to any one of claims 12-14 characterized in that the water-soluble cyanide salt is sodium cyanide. 19. The process of claim 2 characterized in that the rate-promoting agent is an acid salt of a tertiary amine selected from products of the reaction of a strong acid and a linear tertiary polyamine of the formula EMI24.1 wherein Y is -( CH2)k with k being 1-6, C3-C7 cycloalkane, C2-C6 alkenyl, or C2-C6 alkynyl; z is 1 or 2, and when z is 1, m and n are 0 or independently 1-6, and when m and n are 0, R1, R2, R3, and R4 are hydrocarbon groups, and R1 may be joined with R2 and R3 may be joined with R4 to form a ring containing the N atom to which both are joined, and when m is 1-6 and n is 0, R1 and R3 are absent, and R2 and R4 are hydrocarbon groups, and when both m and n are at least 1, R2 and R4 are absent; and when z is 2, m and n are 0, R1 and R3 are hydrocarbon groups and R2 and R4 are absent. 20. The process of claim 19 characterized in that the rate-promoting agent is selected from diazabicyclo l2.2.2]octane dihydrochloride, 2,7-dimethyl-2,7-diazaoctane dihydrochloride, 2,3,4, 6,7,8,9,10-octahydropyri mido[1 ,2-a] azepine hydrochloride, and quinuclidine hydrochloride. 21. The process of claim 20 characterized in that the rate-promoting agent is diazabicyclo[2.2.2]octane dihydrochloride. 22. A process according to any one of claims 19-21 characterized in that R is 3-(2,2-dichloroethenyl)-2,2- d imethylcyclopropyl. --23. A process according to any one of claims 19-21 characterized in that the water-immiscible aprotic solvent is n-heptane. 24. A process according to any one of claims 19-21 characterized in that the water-soluble cyanide salt is sodium cyanide. 25. A process according to any one of claims 3-24 characterized in that R is selected from 1-(4-difluoro methoxyphenyl)-2-methylpropyl and 1- [ (2-chloro-4-tri- fluoromethyl )amino] -2-methylpropyl. 26. A process according to any one of claims 3-24 characterized in that the acyl halide is reacted with 4-fluoro-3-phenoxybenzaldehyde, a 3-(4-halophenoxy) benzaldehy,de, or 6-phenoxy-2-pyridylcarboxaldehyde.

Inventors: BAUM, JONATHAN SHEFFIELD
Applicants: FMC CORPORATION
Application year: 1982
Main classification: C07C120
IPC codes: A01N53, C07D213, A01N43, B01J31, C07C67, C07C255, A01N37, C07C253