反应详情

To a stirred solution of 10.86 g (49.1 mmol) of 5-Bromo-3-methyl-thiophene-2-carboxylic acid (prepared according to D. Spinelli, JCS Perkin Trans. II, 1972, 1866), 6.97 g (51.6 mmol) of 1-Hydroxybenzotriazole hydrate, 9.0 mL (51.7 mmol) of diisopropylethylamine and 12.36 g (51.6 mmol) of L-glutamic acid diethyl ester hydrochloride in 70 mL of DMF was added 9.89 g (51.6 mmol) of 1-(3-Dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride. The reaction mixture was stirred under Argon for 18 hours, poured into H2O and extracted with ethyl acetate. The organic layer was washed sequentially with 0.5N HCl, saturated NaHCO3 soln and saturated NaCl soln, dried over MgSO4, then concentrated under reduced pressure. This residue was purified by flash chromatography on silica gel eluting methylene chloride-ethyl acetate (20:1). In this manner, there was obtained 19.70 g (99%) of the desired product as a colorless oil.

1. extractionextracted with ethyl acetate
2. washThe organic layer was washed sequentially with 0.5N HCl, saturated NaHCO3 soln
3. dry with materialsaturated NaCl soln, dried over MgSO4
4. concentrationconcentrated under reduced pressure
5. customThis residue was purified by flash chromatography on silica gel
6. washeluting methylene chloride-ethyl acetate (20:1)