Efficient Synthesis of Chromeno[4, 3, 2‐de] [1, 6]naphthyridine Derivatives via Pseudo Four‐Component Reaction. Issue 34 (9th September 2021) - Gan, Jianbo
Abstract: A novel approach to the synthesis of substituted 5‐amino‐4‐cyanochromeno[4, 3, 2‐ de ][1, 6]naphthyridine‐1‐carboxylates from a wide range of substituted 2‐hydroxybenzaldehydes with alkyl 3‐oxo‐3‐substituted propanoates and malononitrile was investigated via propionic acid‐promoted cascade Knoevenagel condensation/Michael addition/intramolecularly nucleophilic addition accompanied by oxidative aromatization. This procedure provided a highly efficient and facile route to functionalized chromenonaphthyridines from readily available substrates under mild reaction conditions. Abstract : 5‐Amino‐4‐cyanochromeno[4, 3, 2‐ de ][1, 6]naphthyridine‐1‐carboxylate derivatives were synthesized effecively via propionic acid‐promoted cascade Knoevenagel condensation/Michael addition/intramolecularly nucleophilic addition accompanied by oxidative aromatization.