Methods of manufacturing certain substituted sulfilimines
View Patent ↗Provided are methods and/or systems to convert sulfide intermediates to sulfilimines using a series of continuous loop reactors instead of a batch reactor. The advantages of the methods and systems provided include improved total yield, improved heat management, improved phase mixing, and/or improved volume management.
1. A method of preparing a sulfilimine of Formula (I),
wherein X represents halogen, C 1 -C 4 alkyl or C 1 -C 4 haloalkyl; comprising,
(a) mixing a solution cyanamide, a solution of hypochlorite, and a solvent in a first continuous loop reactor;
(b) transferring the mixture of Step (a) into a second continuous loop reactor;
(c) adding a sulfide of Formula (II) into the second continuous loop reactor which reacts with the mixture of Step (a) to form the sulfilimine,
wherein X is as previously defined; and
(d) decanting the aqueous phase giving an organic phase containing a sulfilimine of Formula (I).
2. The method of claim 1 , wherein X represents CF 3 .
3. The method of claim 1 , wherein the solvent comprises acetonitrile.
4. The method of claim 1 , wherein Step (a) is performed at a temperature between −9° C. and 5° C.
5. The method of claim 1 , wherein Step (a) is performed at a temperature between −5° C. and −3° C.
6. The method of claim 1 , wherein Step (c) is performed at a temperature between −13° C. and 3° C.
7. The method of claim 1 , wherein Step (c) is performed at a temperature between −5° C. and −3° C.
8. The method of claim 1 , wherein the cyanamide/hypochlorite mole ratio is between 1.0 and 2.0, the hypochlorite/sulfide mole ratio is between 1.0 and 2.5, and/or the acetonitrile solvent/sulfide mass ratio is about between 1.5 and 5.
9. The method of claim 1 , wherein the cyanamide/hypochlorite mole ratio is between 1.15 and 1.4, the hypochlorite/sulfide mole ratio is between 1.2 and 1.5, and/or the acetonitrile solvent/sulfide mass ratio is about between 2.5 and 3.