Sodium Hydroxide → O-(9-phenyl-9H-fluoren-9-yl)-L-serine

Participants

Reaction Steps

To a solution of 6.4 g (17.8 mmol) of O-(9-phenyl-9H-fluoren-9-yl)-L-serine methyl ester from step 2 in methanol (20 mL) was added 20% sodium hydroxide (10 mL) and the mixture stirred at room temperature for 1 h. Most of the methanol was evaporated under vacuo, the residue suspended in water (200 mL) and extracted with diethyl ether (2×50 mL). The alkaline aqueous phase was added dropwise into 20% acetic acid (30 mL) with stirring and cooling with an ice bath, the white precipitate was filtered, washed with water and dried in vacuo over P2O5 to give 5.3 g (yield 90%) of O-(9-phenyl-9H-fluoren-9-yl)-L-serine as a white powder. 13C NMR (DMSO-d6, 75 MHz) δ: 167.0, 146.4, 146.1, 143.3, 140.3, 140.0, 129.4, 129.2, 128.4, 128.2, 128.0, 127.2, 125.6, 125.5, 125.1, 120.5, 120.4, 88.4, 63.2, 54.8.

Provenance & Evidence