Ammonia → 6-Amino-3-hydroxy-2-phenyl-4H-chromen-4-one

Beteiligte Stoffe

Reaktionsschritte

With substantial amounts of 4 in hand, the next steps were to form the 6-acetamidoflavonol. Thus, the acetophenone 4 was treated with benzaldehyde and base to effect a Claisen-Schmidt condensation affording the chalcone 5 in 71% yield. The chalcone 5 was treated with alkaline hydrogen peroxide to enable an Algar-Flynn-Oyamada reaction, giving 6-acetamidoflavonol 6 in 50% yield. The next step was to unveil the 6-amino group of 6 to allow coupling with succinic anhydride for installation of the succinamic acid side chain. The 6-acetamidoflavonol 6 was treated with 5 M HCl in ethanol at reflux, followed by neutralization with aqueous ammonia to give 6-aminoflavonol.

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