18-Crown-6 → HCID 53912688, compound

Participants

Reaction Steps

To a stirred solution of (S)-N-[2-(diphenylphosphonomethylamino)-3-(4-biphenylyl)-propionyl]-3-aminopropionic acid (10.8 g, 19.3 mmol) in methanol (150 mL) is added potassium fluoride (11.2 g, 193 mmol) followed by 18-crown-6 (100 mg, 0.38 mmol). The solution is refluxed for 7 minutes in a preheated oil bath then stirred at room temperature for 3 hours. The volume is then reduced to 50 mL by evaporation under reduced pressure. The solution is cooled in an ice bath and treated with 2N hydrochloric acid (55 mL) and water (50 mL). The product is extracted with methylene chloride (3×70 mL). The organic layer is washed with brine then dried over sodium sulfate. The solution is filtered and concentrated in vacuo. The residue is crystallized from ether to give (S)-N-[2-(dimethylphosphonomethylamino)-3-(4-biphenylyl)-propionyl]-3-aminopropionic acid m.p. 122°-123°, [α]D =-10.56° (c=0.86, CH3OH).

Provenance & Evidence