反应详情

To a solution of (2S)-5-amino-2-(tert-butoxycarbonylamino)-pentanoic acid tert-butyl ester (free base) (0.905 g, 3.11 mmol) in CH3OH (15 mL) was added 6,7-dihydro-5H-quinolin-8-one (0.504 g, 3.43 mmol) and the resultant solution was stirred at room temperature for 5 hours. Powdered NaBH4 (0.379 g, 9.98 mmol) was added, and the mixture was stirred at room temperature for 25 minutes then concentrated under reduced pressure. The residue was dissolved in CH2Cl2 (100 mL) and brine (20 mL). The phases were separated and the aqueous phase was extracted with CH2Cl2 (3×20 mL). The combined organic extracts were dried (Na2SO4) and concentrated. Purification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—CH3OH) provided 0.700 g (54%) of (2S)-2-tert-butoxycarbonylamino-5-(5,6,7,8-tetrahydroquinolin-8-ylamino)-pentanoic acid tert-butyl ester as a yellow oil.

1. concentrationthen concentrated under reduced pressure
2. dissolutionThe residue was dissolved in CH2Cl2 (100 mL)
3. customThe phases were separated
4. extractionthe aqueous phase was extracted with CH2Cl2 (3×20 mL)
5. dry with materialThe combined organic extracts were dried (Na2SO4)
6. concentrationconcentrated
7. customPurification of the crude material by column chromatography on silica gel (20:1 CH2Cl2—CH3OH)