Lanthanum–Catalyzed One–Pot Synthesis of Chromeno–Fused Pyridine/Quinolinone Derivatives
A facile one–pot method has been developed for the synthesis of chromeno fused pyridine/quinolinone derivatives. The reactions proceeded through the formation C−O, C−N and C−C bonds to form the title compounds. The bio–active compound 6H-chromeno[4,3-b] quinolin-6-one has been prepared by this protocol.
Abstract
A novel one-pot approach has been developed for the preparation of 5-oxo-5H-chromeno[4,3-b] pyridine-3-carboxylates and 6H-chromeno[4,3-b] quinolin-6-ones by reacting 2-((benzylimino/phenylimino)-methyl) phenols with ethyl/methyl propiolate in presence of La(OTf)3 under thermal conditions. The reactions proceeded through the formation C−O, C−N and C−C bonds to form the title compounds. The bio–active compound 6H-chromeno[4,3-b] quinolin-6-one has been prepared by this protocol.
