Citric Acid → HCID 136376437, compound

Participants

Reaction Steps

Tert-butyl{6-[amino(hydroxyimino)methyl]-2-isobutyl-1-oxo-4-phenyl-1,2-dihydroisoquinolin-3-yl}methylcarbamate (0.25 g, 0.54 mmol) was dissolved in ethyl acetate (10 ml) and N,N′-carbonyldiimidazole (0.26 g, 1.6 mmol) was added. The mixture was refluxed under heating for 3 h. To the reaction mixture were added 0.1 M aqueous citric acid solution (25 ml) and ethyl acetate (50 ml). The organic layer was washed with 0.1 M aqueous citric acid solution (25 ml), and then saturated brine (25 ml), dried over anhydrous magnesium sulfate (12 g) and concentrated under reduced pressure. The residue was recrystallized from diisopropyl ether-ethyl acetate=2:1 (v/v) to give tert-butyl[2-isobutyl-1-oxo-6-(5-oxo-4,5-dihydro-1,2,4-oxadiazol-3-yl)-4-phenyl-1,2-dihydro-3-isoquinolinyl]methylcarbamate (0.24 g, 93%) as a colorless powder.

Provenance & Evidence