反应详情

Ethanol (36 ml) was added to bromoacetic acid (5.00 g, 36.0 mmol), and the mixture was stirred under ice-cold water-cooling. Propylamine (14.8 ml, 180 mmol) was added to the mixture over one minute, and then the whole was stirred at an external temperature of 80° C. for 2.5 hours. A 4 N aqueous sodium hydroxide solution (27 ml) was added to the reaction mixture, the whole was concentrated under reduced pressure, then water (27 ml) and tetrahydrofuran (30 ml) were added to the concentrate, and the whole was stirred at room temperature. A solution of di-t-butyl carbonate (9.43 g, 43.2 mmol) in tetrahydrofuran (6 ml) was added thereto, and after 15 minutes, citric acid monohydrate was added thereto to weakly acidify the whole. The whole was extracted with ethyl acetate (150 ml). The organic layer was washed with water (100 ml) and saturated brine (50 ml) successively, dried over sodium sulfate and concentrated under reduced pressure. The resulting residue was separated by silica gel column chromatography to give 2-[N-(t-butoxycarbonyl)-N-propylamino]acetic acid (5.06 g, 65%) as a colorless solid.

1. temperaturecooling
2. stirringthe whole was stirred at an external temperature of 80° C. for 2.5 hours
3. concentrationthe whole was concentrated under reduced pressure
4. additionwater (27 ml) and tetrahydrofuran (30 ml) were added to the concentrate
5. stirringthe whole was stirred at room temperature
6. extractionThe whole was extracted with ethyl acetate (150 ml)
7. washThe organic layer was washed with water (100 ml) and saturated brine (50 ml) successively
8. dry with materialdried over sodium sulfate
9. concentrationconcentrated under reduced pressure
10. customThe resulting residue was separated by silica gel column chromatography