反应详情

One molar equivalent of 3-chloro-2-fluoro-benzyl bromide (commercially available from e.g., Lancaster Synthesis, Ltd.) is permitted to react with 2 molar equivalents of potassium isothiocyanate in dimethylformamide (DMF) containing 0.5 molar equivalent of NaI at 90° C. for 5 hours with stirring to yield 3-chloro-2-fluorobenzyl isothiocyanate. The reaction mixture is permitted to cool to room temperature, and the solution is diluted with H20 and extracted with ether. The ether phase containing the product is removed and the reaction mixture extracted twice more with fresh ether. The ether phases are combined and the product is concentrated in a Speed Vac® vacuum centrifuge (using house vacuum) set in a water bath at about 45° C. When the ether has evaporated, the unpurified 3-chloro-2-fluorobenzyl isothiocyanate is a viscous liquid.