20358-06-9

656-32-6

20358-06-9

General procedure for the synthesis of 2-amino-4-fluorobenzothiazole from 1-(2-fluorophenyl)-2-thiourea: A solution of bromine (0.51 mL, 10.0 mmol) was added slowly and dropwise to a suspension of 1-(2-fluorophenyl)-2-thiourea (1.7 g, 10.0 mmol) in chloroform (25 mL) at room temperature. The reaction mixture was heated to reflux for 3 hours. Upon completion of the reaction, the solvent was removed by evaporation and water was added to the residue and neutralized with ammonium hydroxide solution. The resulting white precipitate was collected by filtration and dried to give 1.2 g (72% yield) of 2-amino-4-fluorobenzothiazole, which could be used in subsequent reactions without further purification.