反应详情

Under a nitrogen purge, a solution of 2-(p-chlorophenyl)-5-[(trifluoromethyl)thio]pyrrole-3-carbonitrile (0.6 g, 0.002 mol) in tetrahydrofuran is treated with N-bromosuccinimide (0.36 g, 0.002 mol), stirred for 16 hours at room temperature and concentrated in vacuo to obtain a residue. The residue is dissolved in ether and diluted with water. The organic phase is separated, washed with water and brine, dried over anhydrous magnesium sulfate and concentrated in vacuo to obtain a solid. High performance liquid chromatography indicates that the solid contains 20% starting material. A solution of the mixture and sodium acetate (0.05 g, 0.006 mol) in acetic acid is treated with bromine (0.03 mL, 0.0006 mol), stirred for 16 hours at 60° C., cooled and concentrated in vacuo to obtain a semi-solid. The semi-solid is partitioned between ethyl acetate and water. The organic phase is separated, washed with water and brine, dried over anhydrous magnesium sulfate and concentrated in vacuo to obtain a solid. The solid is recrystallized from ethylene dichloride to give the title product as an off-white solid (mp 241°-243° C.) which is identified by 1 HNMR and 13CNMR spectral analyses.

1. customUnder a nitrogen purge
2. concentrationconcentrated in vacuo
3. customto obtain a residue
4. customThe organic phase is separated
5. washwashed with water and brine
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated in vacuo
8. customto obtain a solid
9. stirringstirred for 16 hours at 60° C.
10. temperaturecooled
11. concentrationconcentrated in vacuo
12. customto obtain a semi-solid
13. customThe semi-solid is partitioned between ethyl acetate and water
14. customThe organic phase is separated
15. washwashed with water and brine
16. dry with materialdried over anhydrous magnesium sulfate
17. concentrationconcentrated in vacuo
18. customto obtain a solid
19. customThe solid is recrystallized from ethylene dichloride