Sodium Hydroxide → 5,6-dihydro-2-(2-phenylethyl)-4H-imidazo[4,5,1-ij]quinolin-6-ol

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Reaction Steps

A portion (2.7 g) of the less polar fraction of 5,6-dihydro-2-(2-phenylethyl)-6-((-)-4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane-1-carbonyloxy)-4H-imidazo[4,5,1-ij]quinoline obtained in Step 1 was dissolved in methanol (200 mL), followed by the addition of 2N aqueous sodium hydroxide (60 mL) and subsequent stirring at room temperature for 2 hrs; thereafter, the mixture was concentrated under reduced pressure and, to the residue was added water followed by extraction with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate, then the solvents was removed under reduced pressure, and the residue was recrystallized from acetone-hexane to yield the titled (+)-5,6-dihydro-2-(2-phenylethyl)-4H-imidazo[4,5,1-ij]quinolin-6-ol (1.2 g). The more polar fraction (3.7 g) was similarly treated to yield the titled (-)-5,6-dihydro-2-(2-phenylethyl)-4H-imidazo[4,5,1-ij]quinolin-6-ol (1.7 g).

Provenance & Evidence