5,6-difluoro-3H-1,3-benzothiazole-2-thione synthesis

Yield:786657-48-5 40%

Reaction Conditions:

in N,N-dimethyl-formamide at 95; for 7 h;

Steps:

202.a.1

Step 1: 5,6-Difluoro-benzothiazole-2-thiol A mixture of 1 g (6.80 mmol) 2,4,5-trifluoroaniline and 1.33 g (8.16 mmol) potassium ethylxanthogenate in 5 mL dry N,N-dimethylformamide was heated in a 95° C. oil bath for 7 h. The reaction mixture was cooled to room temperature and diluted with water (15 mL). The mixture was acidified with aqueous HCl 2N. The precipitate was collected by filtration, washed with water and dried to provide 0.55 g (40%) of the titled compound as a light yellow solid. MS(m/e): 201.9 (M-H⁺).

References:

US2009/163485,2009,A1 Location in patent:Page/Page column 52