反应详情

To a solution of 0.032 g (0.085 mmol) N-methyl--O--(9-phenyl-9H-fluoren-9-yl)-L-serine methyl ester from Step 1 in methanol (1 mL) was added 20% sodium hydroxide (1 mL) and the mixture stirred at room temperature for 1 h. Most of the ethanol was evaporated under vacuo, the residue suspended in water (5 mL) nd extracted with diethyl ether (2×1 mL). The alkaline aqueous phase was acidified with 20% acetic acid by cooling with an ice bath, the white precipitate was filtered, washed with water and dried in vacuo over P2O5 to give 0.027 g (yield 90%) N-methyl--O--(9-phenyl-9H-fluoren-9-yl)-L-serine as a white powder.

1. customMost of the ethanol was evaporated under vacuo
2. extractionextracted with diethyl ether (2×1 mL)
3. temperatureby cooling with an ice bath
4. filtrationthe white precipitate was filtered
5. washwashed with water
6. dry with materialdried in vacuo over P2O5