tert-Butanol → (4S)-11-[2-(dimethyl-pyrrolidin-1-ylmethyl-silanyl)-ethyl]-4-ethyl-4-hydroxy-1,12-dihydro-4H-2-oxa-6,12a-diaza-dibenzo[b,h]fluorene-3,13-dione

Participants

Reaction Conditions

Reaction Steps

A slurry of Compound 4 (60 mg) and K2CO3 (43 mg) in deionized water (1 mL) was stirred at room temperature for 30 min. To the resulting reaction mixture, t-BuOH (1 mL) and pyrrolidine (52 μL) were added and heated at 70° C. for 5 hours. The reaction mixture was then concentrated under reduced pressure and the residue was dissolved in acetic acid (10 mL) and stirred at room temperature for 2 hours. The acetic acid solution was concentrated again under vacuum. Finally, the residue was partitioned between chloroform (2×15 mL) and 7% aqueous NaHCO3 solution (5 mL). The collective organic layers were dried, concentrated and purified on a silica gel using 10% ethanol in dichloromethane to afford the required product in 83% yield (45 mg).

Provenance & Evidence