Methods of producing a sulfilimine compound, such as N-cyano-S-methyl-S-[1-(6-trifluoromethyl-3-pyridinyl)ethyl]sulfilimine or other substituted sulfilimine compound. The method includes combining a sulfide compound, cyanamide, a hypochlorite compound, and a base, and oxidizing the sulfide compound to form the sulfilimine compound. The sulfide compound may include a 2-trifluoromethyl-5-(1-substituted)alkyl-thiopyridine compound. The base may include sodium hydroxide. A buffer, such as a phosphate buffer, may, optionally, be used in the reaction.