Patent CH-702299-B1 (CH)
Title: Forming perfluoromethyl sulfenyl chloride as an intermediate for preparing e.g. insecticides involves reacting halogenated aromatic compound with fluoride compounds e.g. potassium bifluoride and sodium fluoride, and thiophosgene in solvent
Inventor: GHARDA KEKI HORMUSJI
IPC: C07C313/08
Filed: 2010-07-05
Abstract: Preparing perfluoromethyl sulfenyl chloride involves reacting halogenated aromatic compound with fluoride compounds e.g. potassium bifluoride and sodium fluoride, and thiophosgene in a solvent e.g. acetonitrile; pulverizing the reaction mass by using beads e.g. glass and/or zirconium oxide beads; isolating trifluoromethyl thiomethyl benzene derivative from the mixture; distilling the benzene derivative; dissolving purified benzene derivative in a solvent e.g. dichloromethane; and cleaving the benzene derivative by selective chlorinolysis by passing chlorine gas at -10 to 30[deg] C. Preparation of perfluoromethyl sulfenyl chloride involves reacting halogenated aromatic compound of formula R'-CH 2-R (I) with at least one fluoride compound selected from potassium fluoride, potassium bifluoride, sodium fluoride, tetramethylammonium fluoride and benzyltrimethylammonium fluoride and thiophosgene in a solvent selected from acetonitrile, dichloromethane, sulfolane and carbon tetrachloride to obtain a reaction mass; pulverizing the reaction mass with the help of beads selected from glass, sand, stainless steel, titanium and/or zirconium oxide beads to obtain a mixture containing trifluoromethyl thiomethyl benzene derivative; isolating the trifluoromethyl thiomethyl benzene derivative from the mixture; distilling the trifluoromethyl thiomethyl benzene derivative to obtain a purified trifluoromethyl thiomethyl benzene derivative; dissolving the purified trifluoromethyl thiomethyl benzene derivative in a solvent selected from dichloromethane, toluene, benzene, ethylene dichloride, mono chloro benzene, carbon tetrachloride, ortho dichloro benzene and trichloro benzene; and cleaving the trifluoromethyl thiomethyl benzene derivative by selective chlorinolysis by passing chlorine gas at -10 to 30[deg] C. R : optionally substituted aromatic group; R' : halo selected from fluoro, chloro, bromo and iodo. An independent claim is included for a system for the preparation of perfluoromethyl sulfenyl chloride comprising a reactor containing an inlet for facilitating entry of reactants into the reactor, an outlet for facilitating exit of final product out of the reactor, a stirrer for mixing the reactants contained inside the reactor, a cooler for preventing overheating of the reactants, a temperature measuring and indicating unit for measuring and indicating the temperature of the resulting mixture of the reactants contained inside the reactor, and a pressure gauge for measuring pressure generated inside the reactor; a pump for moving the resulting mixture contained inside the reactor; and a bead mill comprising beads for pulverization of the resulting mixture moved from the gear pump, where the pulverized mixture enter into the reactor for further mixing; and the final product formed after subsequent mixing is existed through the outlet of the reactor.