反应详情

To a solution of (diethylamino)sulfur trifluoride (0.24 mL, 1.82 mmol) in DCM (2.7 mL) pyridine (0.27 mL, 3.34 mmol) was added followed by dropwise addition of 5-bromo-3-[(trans-4-hydroxy-cyclohexyl)-(trans-4-methyl-cyclohexanecarbonyl)-amino]-thiophene-2-carboxylic acid methyl ester (150 mg, 0.32 mmol) in DCM (2.0 mL) during 10 min. The mixture was stirred for 16 h at room temperature. It was cooled in ice-bath and saturated NaHCO3 was added slowly to neutralize the excess reagent. The mixture was stirred at room temperature for 3 h. It was extracted with DCM (100 mL), washed with brine, dried (MgSO4) and evaporated. The crude was chromatographed over silica gel (hexane:EtOAc—95:5 and 90:10 as eluents) yielding pure 5-bromo-3-[(cis-4-fluoro-cyclohexyl)-(trans-4-methyl-cyclohexanecarbonyl)-amino]-thiophene-2-carboxylic acid methyl ester (28 mg, 18%) and 5-bromo-3-[(trans-4-fluoro-cyclohexyl)-(trans-4-methyl-cyclohexanecarbonyl)-amino]-thiophene-2-carboxylic acid methyl ester (22 mg, 14%).

1. temperatureIt was cooled in ice-bath
2. stirringThe mixture was stirred at room temperature for 3 h
3. extractionIt was extracted with DCM (100 mL)
4. washwashed with brine
5. dry with materialdried (MgSO4)
6. customevaporated
7. customThe crude was chromatographed over silica gel (hexane:EtOAc—95:5 and 90:10 as eluents)