Hydrochloric Acid → (1E,6E)-1-(1H-indol-6-yl)-7-[2-methoxy-4-(2-tetrahydrofuranylmethoxy)phenyl]hepta-1,6-diene-3,5-dione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 20 mL reaction vessel were placed 19.3 mg (85.0 μmol) of 6-(1H-indol-6-yl)hex-5-ene-2,4-dione and 22 mg (0.32 mol) of boron oxide and they were dissolved in 0.4 mL of ethyl acetate. To the mixture under stirring at 70° C., 20 mg (85 μmol) of 2-methoxy-4-(2-tetrahydrofuranylmethoxy)benzaldehyde and 32 μL (0.14 mmol) of triisopropyl borate were sequentially added. After the mixture was stirred at the same temperature for 1 hour, 18 μL (0.18 mmol) of piperidine was added and the mixture was further stirred for 1 hour. To the reaction mixture was added a 1:1 solution (2 mL) of 1 N hydrochloric acid and saturated brine at room temperature and the mixture was stirred for 5 minutes to 1 hour (further, the mixture was neutralized with a saturated sodium bicarbonate aqueous solution as needed). The resulting organic phase was directly subjected to purification by silica gel column chromatography (hexane/ethyl acetate or methylene chloride/methanol) to give 10.2 mg (27% yield) of the title compound as an orange powder with the following properties.

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