反应详情

To a solution of 0.28 g (2 mmol) of glycine ethyl ester hydrochloride and 0.28 mL (2 mmol) of triethylamine in 10 mL of chloroform, 0.52 g (2 mmol) of N-(tert-butoxycarbonyl)-3-chloro-L-alanine in 6 mL of chloroform and 0.42 g (2 mmol) of dicyclohexylcarbodiimide were added at 0° C. The reaction mixture was stirred for 16 hours at room temperature. The resultant precipitate was removed by filtration and the filtrate was washed successively with 0.5N hydrochloric acid, water and 3% aqueous sodium bicarbonate, then was dried over anhydrous sodium sulfate. Removal of the solvent left a crystalline residue which was recrystallized from a mixture of ethyl acetate and n-hexane to give 0.415 g (60%) of the pure product melting at 71.5°-72.0° C. The identity of the product, which has the structural formula ##STR56## was confirmed by IR and NMR analyses.

1. customThe resultant precipitate was removed by filtration
2. washthe filtrate was washed successively with 0.5N hydrochloric acid, water and 3% aqueous sodium bicarbonate
3. dry with materialwas dried over anhydrous sodium sulfate
4. customRemoval of the solvent
5. waitleft a crystalline residue which
6. customwas recrystallized from a mixture of ethyl acetate and n-hexane