Process for the preparation of certain substituted sulfilimines
View Patent ↗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 , 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 , COOR 4 , CONR 4 R 5 , or aryl;
n is an integer from 0-3;
L represents either a single bond or —CH 2 ;
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, or arylalkyl;
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, arylalkyl, or, alternatively, 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, or arylalkyl; 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, or arylalkyl;
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 temperature is from about −10° C. to about 10° C.
5. 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.
6. The process of claim 1 in which the organic solvent is a halogenated aliphatic hydrocarbon or an aliphatic nitrile.
7. 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.