Process for the preparation of 1,4-diaryl-2-fluoro-4-cyano-2-butenes and intermediates useful therefor

Abstract

The present invention provides a process for the preparation of pesticidal 1,4-diaryl-2-fluoro-4-cyano-2-butene compounds having the structural formula I and intermediates useful therefor.

What is claimed is:  
     
         1 . A process for the preparation of a compound of formula I  
       
         
           
           
               
               
           
         
       
       wherein 
 Ar is phenyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups, or 
 1- or 2-naphthyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups;  
 
 R is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 3 -C 6 cycloalkyl or C 3 -C 6 halocycloalkyl; and  
 Ar 1  is phenoxyphenyl optionally substituted with any combination of from one to six halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups, 
 phenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 biphenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 phenoxypyridyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 ,-C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 benzylpyridyl optionally substituted with any combination of from one to five halogen, C l -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 benzylphenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 benzoylphenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 1- or 2-naphthyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups; or the optical isomers thereof; or  
 
 the cis and trans isomers thereof,  
 which process comprises the following steps: 
 a) reacting an intermediate of formula II  
                     
  wherein Ar 1  is defined as above and X is chloro, bromo, iodo, tosyloxy, mesyloxy or the like with a cyanide delivering reagent in a first solvent to afford a cyano intermediate of formula III  
                     
 
 b) reacting said cyano intermediate III with an aldehyde of formula IV  
                      in the presence of a base in a second solvent to yield an anion which is acidified to afford a diene of formula V                          c) reacting said diene of formula V with magnesium in the presence of a third solvent to give the desired formula I product.    
 
     
     
         2 . The process according to  claim 1  wherein said cyanide delivering reagent is an alkali metal cyanide.  
     
     
         3 . The process according to  claim 2  wherein the alkali metal cyanide is sodium cyanide or potassium cyanide.  
     
     
         4 . The process according to  claim 1  wherein said first solvent is a polar aprotic solvent selected from the group consisting of dimethylsulfoxide. dimethylformamide and N-methylpyrrolidone.  
     
     
         5 . The process according to  claim 4  wherein the polar aprotic solvent is dimethylsulfoxide.  
     
     
         6 . The process according to  claim 1  wherein the said base is an alkali metal amide.  
     
     
         7 . The process according to  claim 6  wherein the alkali metal amide is lithium diisopropylamide.  
     
     
         8 . The process according to  claim 1  wherein said acid is a strong mineral acid.  
     
     
         9 . The process according to  claim 8  wherein said strong mineral acid is sulfuric acid or hydrochloric acid.  
     
     
         10 . The process according to  claim 1  wherein said third solvent is an alkanol.  
     
     
         11 . The process according to  claim 10  wherein the alkanol is methanol or ethanol.  
     
     
         12 . A compound of formula I or V  
       
         
           
           
               
               
           
         
       
       wherein 
 Ar is phenyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups, 
 1- or 2-naphthyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups, or  
 
 R is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 3 -C 6 cycloalkyl or C 3 -C 6 halocycloalkyl;  
 Ar 1  is phenoxyphenyl optionally substituted with any combination of from one to six halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups, 
 phenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 biphenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 phenoxypyridyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 benzylpyridyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 benzylphenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 benzoylphenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups,  
 1- or 2-naphthyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups; or  
 
 the optical isomers thereof; or  
 the cis and trans isomers thereof.  
 
     
     
         13 . The compound of formula V according to  claim 12  wherein 
 Ar is phenyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1-C   4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups;  
 R and is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 3 -C 6 cycloalkyl or C 3 -C 6 halocycloalkyl;  
 Ar 1  is 3-phenoxyphenyl optionally substituted with any combination of from one to six halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups, 
 3-biphenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups, or  
 3-benzylphenyl optionally substituted with any combination of from one to five halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups.  
 
 
     
     
         14 . The compound according to  claim 13  wherein 
 Ar is phenyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups;  
 R is isopropyl or cyclopropyl; and  
 Ar 1  is 3-phenoxyphenyl optionally substituted with any combination of from one to six halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups.  
 
     
     
         15 . The compound according to  claim 14  wherein 
 Ar is phenyl optionally substituted with any combination of from one to three halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups;  
 R is cyclopropyl; and  
 Ar 1  is 3-phenoxyphenyl optionally substituted with any combination of from one to six halogen, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy or C 1 -C 4 haloalkoxy groups.