反应详情

To a solution of (4S)-2-(4-carboxy-2-methylphenylimino)-3,4-diisobutyl-1,3-thiazolidine (0.035 g, 0.10 mmol) in CH2Cl2 (5 mL) was added carbonyl diimidazole (0.047 g, 0.29 mmol). The mixture was allowed to stir at room temp. for 2 h, then anh NH3 (approximately 30 drops) was condensed into the solution at −78° C. The resulting mixture was warmed to room temp. overnight, then treated with H2O (20 mL). The aqueous layer was extracted with CH2Cl2 (3×20 mL), sequentially washed with H2O (20 mL) and a saturated NaCl solution (20 mL), dried Na2SO4), and concentrated under reduced pressure. The residue was purified by flash chromatography (40% EtOAc/hexane) to give (4S)-2-(4-carbamoyl-2-methylphenylimino)-3,4-diisobutyl-1,3-thiazolidine as a white solid (0.027 g, 73%): mp 130-131° C.

1. customcondensed into the solution at −78° C
2. temperatureThe resulting mixture was warmed to room temp. overnight
3. extractionThe aqueous layer was extracted with CH2Cl2 (3×20 mL)
4. washsequentially washed with H2O (20 mL)
5. concentrationa saturated NaCl solution (20 mL), dried Na2SO4), and concentrated under reduced pressure
6. customThe residue was purified by flash chromatography (40% EtOAc/hexane)