反应详情

Sulfuryl chloride (9.09 g, 67.33 mmol) was added with stirring to 2-mercapto-5-(trifluoromethyl)benzothiazole (2.64 g, 11.22 mmol) over a period of 5 minutes. The reaction mixture was then allowed to stand for approximately 1 h. Ice water was added to the reaction mixture with stirring to decompose the excess of sulfuryl chloride, and the product was then extracted with ethyl acetate. The organic layer was washed with water (3×) and brine, dried over anhydrous Na2SO4 and concentrated. The resulting solid was dissolved in EtOAc and filtered though a short silica-gel column, eluting with EtOAc, to give 2-chloro-5-(trifluoromethyl)benzothiazole (2.50 g, 94%). LC-MS m/z 238.0 (MH+), ret. time 2.55 min; 1H NMR (400 MHz, DMSO-d6) δ 7.81 (d, 1H), 8.38 (m, 2H).

1. extractionthe product was then extracted with ethyl acetate
2. washThe organic layer was washed with water (3×) and brine
3. dry with materialdried over anhydrous Na2SO4
4. concentrationconcentrated
5. dissolutionThe resulting solid was dissolved in EtOAc
6. filtrationfiltered though a short silica-gel column
7. washeluting with EtOAc