Piperidine → (1E,6E)-1-(1H-indol-6-yl)-7-[4-(2-morpholinoethoxy)phenyl]hepta-1,6-diene-3,5-dione

Participants

Reaction Conditions

Reaction Steps

To 2.5 g of (E)-6-(1H-indol-6-yl)hex-5-ene-2,4-dione were added 44 mL of AcOEt and 1.07 g of boron oxide, and the mixture was stirred at 70° C. for 40 minutes. To this, 2.27 g of 4-(2-morpholinoethoxy)benzaldehyde and 7.07 mL of tributyl borate were successively added, and the mixture was stirred at the same temperature for 40 minutes. Then, 0.11 mL of piperidine was added, and the mixture was stirred at 70° C. for 1.5 hours and was allowed to cool back to room temperature. To the reaction mixture, 22 mL of a 20% K2CO3 aqueous solution and 20 mL of THF were added and the mixture was stirred at room temperature for 10 minutes. The organic layer was separated, washed with saturated brine, dried over MgSO4, and concentrated. The residue was purified by silica gel column chromatography (CHCl3/acetone or CHCl3/methanol system) to give 1.62 g of the title compound (33% yield).

Provenance & Evidence