Synthesis
General procedure for the synthesis of 6-fluorobenzothiazol-2-one using the compound (CAS:1373399-24-6) as starting material: ethyl 2-iodophenylcarbamate (1 mmol), cuprous iodide (CuI, 19 mg, 0.1 mmol), and sodium sulfide hydrate nine (Na2S-9H2O, 3 mmol) were added sequentially to a Schlenk tube. The reaction system was evacuated and displaced with argon (repeated 3 times), and then N,N-dimethylformamide (DMF, 2 mL) was added. The reaction mixture was stirred at 80 °C for 10 to 16 hours. Upon completion of the reaction, acetic acid (AcOH, 3 mL) was added to the cooled reaction mixture and the mixture was continued to be stirred at 130°C for 36 hours. At the end of the reaction, saturated sodium bicarbonate solution (10 mL) was added for neutralization, followed by extraction of the reaction mixture with ethyl acetate. The organic layers were combined, washed sequentially with water, saturated saline and dried with anhydrous sodium sulfate (Na2SO4). After the solvent was removed by distillation under reduced pressure, the resulting crude product was purified by silica gel column chromatography to finally obtain the target product 6-fluorobenzothiazol-2-one.
References
[1] Tetrahedron Letters, 2012, vol. 53, # 20, p. 2511 - 2513
