反应详情

Crude 4-methyl-1-(3-nitro-5-trifluoromethyl-phenyl)-1H-imidazole (IX) (1.85 g, 6 mmol, 88 area % purity in HPLC) is dissolved in ethyl acetate (6 mL) at about 50° C. To the stirred resulting black solution is slowly added methanesulfonic acid (0.397 mL, 6 mmol) at about 50° C. At the end of the addition a bright solid starts to precipitate. The mixture is allowed to slowly cool down to room temperature and is further stirred at about 5° C. for 75 minutes. The solid formed is filtered, washed with ethyl acetate (4 mL) and dried at room temperature and reduced pressure. A suspension of the obtained material in 2-propanol (5 mL) is stirred at 50° C. for 90 minutes, is allowed to cool down to room temperature, stirred for 1 hour and at 0-5° C. for another hour. The solid formed is filtered, washed with cold 2-propanol (5 mL) and dried at room temperature and reduced pressure to afford 4-methyl-1-(3-nitro-5-trifluoromethyl-phenyl)-1H-imidazole methanesulfonic acid salt as a beige solid. Yield: 54.1% (HPLC purity: 99.5 area %), Melting point: 208-213° C.

1. customTo the stirred resulting black solution
2. customat about 50° C
3. additionAt the end of the addition a bright solid starts
4. customto precipitate
5. customThe solid formed
6. filtrationis filtered
7. washwashed with ethyl acetate (4 mL)
8. customdried at room temperature
9. additionA suspension of the obtained material in 2-propanol (5 mL)
10. stirringis stirred at 50° C. for 90 minutes
11. temperatureto cool down to room temperature
12. stirringstirred for 1 hour and at 0-5° C. for another hour
13. customThe solid formed
14. filtrationis filtered
15. washwashed with cold 2-propanol (5 mL)
16. customdried at room temperature