反应详情

温度

60 °C

To a solution of 6-aminobenzothiazol-2-yl tert-butyl carbamate (Intermediate 4, 0.900 g, 3.39 mmol) in pyridine (8 mL), 4-trifluoromethoxybenzoyl chloride (0.535 mL, 3.39 mmol) was added. After stirring for 2 h at 60° C., the solution was poured into water (100 mL). The resulting precipitate was filtered off, washed with water and dried. The so obtained solid was dissolved in dichloromethane (20 mL) and trifluoroacetic acid (20 mL) was added. After stirring for 3 h at r.t., the volatiles were removed in vacuo and dimethyl-formamide (100 mL) was added to the residue. The solution was neutralised by adding saturated sodium hydrogencarbonate solution. Water (400 mL) was added and the mixture was stirred overnight. The precipitated N-(2-aminobenzothiazol-6-yl)-4-trifluoromethoxy-benzamide was filtered off, washed with water and dried (grey solid, 1.16 g, 3.27 mmol, 84%). LC/ESI-MS: m/z=354 [M+H]+; m/z=352 [M−H]−; Rt=3.20 min.

1. filtrationThe resulting precipitate was filtered off
2. washwashed with water
3. customdried
4. dissolutionThe so obtained solid was dissolved in dichloromethane (20 mL)
5. additiontrifluoroacetic acid (20 mL) was added
6. stirringAfter stirring for 3 h at r.t.
7. customthe volatiles were removed in vacuo and dimethyl-formamide (100 mL)
8. additionwas added to the residue
9. additionby adding saturated sodium hydrogencarbonate solution
10. additionWater (400 mL) was added
11. stirringthe mixture was stirred overnight
12. filtrationThe precipitated N-(2-aminobenzothiazol-6-yl)-4-trifluoromethoxy-benzamide was filtered off
13. washwashed with water
14. customdried (grey solid, 1.16 g, 3.27 mmol, 84%)