Process for the preparation of certain substituted sulfilimines

Abstract

Cyano-substituted sulfilimines are produced efficiently and in high yield from the corresponding sulfides by reaction with cyanamide and hypochlorite.

1 . A process for preparing sulfilimines of formula (I), 
       
         
           
           
               
               
           
         
         wherein
 Het represents: 
 
       
       
         
           
           
               
               
           
         
         X represents halogen, C 1 -C 4  alkyl, C 1 -C 4  haloalkyl, C 2 -C 4  alkenyl, C 2 -C 4  alkynyl, C 2 -C 4  haloalkenyl, C 1 -C 4  alkoxy, C 1 -C 4  haloalkoxy, CN, NO 2 , SO m R 6  where m is an integer from 0-2, COOR 4  or CONR 4 R 5 ; 
         Y represents hydrogen, halogen, C 1 -C 4  alkyl, C 1 -C 4  haloalkyl, C 2 -C 4  alkenyl, C 2 -C 4  alkynyl, C 2 -C 4  haloalkenyl, C 1 -C 4  alkoxy, C 1 -C 4  haloalkoxy, CN, NO 2 , SO m R 1  where m is an integer from 0-2, COOR 4 , CONR 4 R 5 , aryl or heteroaryl; 
         n is an integer from 0-3; 
         L represents either a single bond, —CH(CH 2 ) p — where R 1 , S and L taken together represent a 4-, 5-, or 6-membered ring and p is an integer from 1-3, —CH(CH 2 OCH 2 )— where R 1 , S and L taken together represent a 6-membered ring, or —CH— where L, R 2  and the common carbon to which they connect taken together represent a 4-, 5-, or 6-membered ring with up to, but no more than, 1 heteroatom; 
         R 1  represents C 1 -C 4  alkyl, C 1 -C 4  haloalkyl, C 3 -C 6  alkenyl, C 3 -C 6  alkynyl, C 3 -C 6  haloalkenyl, arylalkyl, heteroarylalkyl, or —CH 2 — in cases where R 1 , S and L taken together represent a 4-, 5-, or 6-membered ring; 
         R 2  and R 3  independently represent hydrogen, halogen, C 1 -C 4  alkyl, C 1 -C 4  haloalkyl, C 2 -C 4  alkenyl, C 2 -C 4  alkynyl, C 2 -C 4  haloalkenyl, C 1 -C 4  alkoxy, C 1 -C 4  haloalkoxy, CN, SO m R 6  where m is an integer from 0-2, COOR 4 , CONR 4 R 5 , arylalkyl, heteroarylalkyl, or R 2  and R 3  and the common carbon to which they attach form a 3-6 membered ring; 
         R 4  and R 5  independently represent hydrogen, C 1 -C 4  alkyl, C 1 -C 4  haloalkyl; C 3 -C 6  alkenyl, C 3 -C 6  alkynyl, C 3 -C 6  haloalkenyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl; and 
         R 6  represents C 1 -C 4  alkyl, C 1 -C 4  haloalkyl, C 3 -C 6  alkenyl, C 3 -C 6  alkynyl, C 3 -C 6  haloalkenyl, arylalkyl or heteroarylalkyl; 
       
       which comprises contacting a sulfide of formula (II) 
       
         
           
           
               
               
           
         
         wherein 
         R 1 , R 2 , R 3 , L, Het and n are as previously defined 
       
       with cyanamide and hypochlorite solution at a temperature from about −40° C. to about 30° C. in a suitable organic solvent that is essentially inert to the reaction conditions. 
     
     
         2 . The process of  claim 1  in which Het is (6-substituted)pyridin-3-yl and where X is halogen or C 1 -C 2  haloalkyl and Y is hydrogen. 
     
     
         3 . The process of  claim 1  in which the sulfilimine has the structure 
       
         
           
           
               
               
           
         
         wherein 
         Het, R 2  and R 3  are as previously defined, R 1  is methyl, n is 1, and L is a single bond. 
       
     
     
         4 . The process of  claim 1  in which the sulfilimine has the structure 
       
         
           
           
               
               
           
         
         wherein 
         n is 1, R 1 , S and L taken together form a standard 4-, 5-, or 6-membered ring such that L is —CH(CH 2 ) p — and p is an integer from 1-3, and R 1  is —CH 2 — and Het, R 2  and R 3  are as previously defined. 
       
     
     
         5 . The process of  claim 1  in which the sulfilimine has the structure 
       
         
           
           
               
               
           
         
         wherein 
         n is 0, R 1 , S and L taken together form a standard 4-, 5-, or 6-membered ring such that L is —CH(CH 2 ) p — and p is an integer from 1-3, and R 1  is —CH 2 — and Het is as previously defined. 
       
     
     
         6 . The process of  claim 1  in which the temperature is from about −10° C. to about 10° C. 
     
     
         7 . The process of  claim 1  in which the hypochlorite solution is commercial Clorox bleach which contains about 5 to about 6 weight percent sodium hypochlorite in water. 
     
     
         8 . The process of  claim 1  in which the organic solvent is a halogenated aliphatic hydrocarbon or an aliphatic nitrile. 
     
     
         9 . The process of  claim 1  in which the process is conducted in a biphasic solvent system comprising a mixture a halogenated aliphatic hydrocarbon and water.