Highly efficient synthesis of polyfluorinated 2-mercaptobenzothiazole derivatives

A convenient and efficient method for the synthesis of polyfluorinated 2-mercaptobenzothiazoles from the corresponding aniline derivatives and CS₂, mediated by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in toluene is described. The reaction proceeded via nucleophilic attack at the carbon atom of carbon disulfide by the nitrogen atom of NH₂-group in arene followed by selective intramolecular fluorine atom substitution in the ortho-position to the amino group. This synthetic methodology could be used to prepare fluorinated 2-mercaptobenzothiazole containing alkynyl group in good to excellent yields. The reaction takes place under very mild reaction conditions (50 °C) and uses readily available starting materials.