4-Methylmorpholine → HCID 86756014, compound

Participants

Reaction Steps

To a suspension of 5-amino-2-oxindole (800 mg, 5.4 mM) and N-tert-butoxycarbonylalanine (1020 mg, 5.4 mM) in dichloromethane (50 ml) were added benzotriazol-1-yloxytripyrrolidinophosphonium hexafluorophosphate (2800 mg, 5.6 mM) and N-methylmorpholine (1.2 ml, 11 mM). The mixture was stirred for 15 h at room temperature. Then the solvent was evaporated under vacuum, the residue suspended in water and extracted 3 times with ethyl acetate. The collected extracts were evaporated and then purified by flash chromatography on silica gel using as eluant cyclohexane/ethylacetate 1:9. Thus pure 5-(N-tert-butoxycarbonylalanylamino)-2-oxindole was obtained (600 mg). A solution of the above compound (250 mg, 0.97 mM) in trifluoroacetic acid (15 ml) was maintained for 1 h at room temperature. Then the solution was concentrated under vacuum and ether added to precipitate 5-(alanylamino)-2-oxindole.

Provenance & Evidence