Heterocyclic Systems; 91. Reaction of 4-Oxo-4H-1-benzopyran-3-carboxaldehydes(3-Formylchromones) with 1,2-Diamines

Synthesis of heterocyclic analogs of isoflavone and homoisoflavone based on 3-formylchromone

The review is focused on recent developments of chemistry of synthetic analogs of natural compounds, isoflavone and homoisoflavone. The possible synthetic strategies to access heterocyclic analogs of these compounds starting from readily available 3-formylchromone and its derivatives (3-cyanochromone, 2-amino-3-formylchromone) and products of its condensation with simplest C- and N-nucleophiles are discussed. The structural features of the reaction products that depend on the nature of the reaction medium, structure of the starting compounds, and reagent ratio are considered. Particular attention is given to the application of the modern strategies of organic synthesis, namely green chemistry approaches, click reactions, domino reactions, etc. Examples of compounds of this group most promising for clinical application due to wide and pronounced pharmacological effects are given.

Chromone Studies. Part 14.1 Unprecedented Dimerisation of Chromone-3-Carbaldehyde-Derived Baylis–Hillman Adducts

1,4-Diazabicyclo[2.2.2]octane (DABCO)-catalysed Baylis-Hillman reactions of selected chromone-3-carbaldehydes with methyl acrylate have been shown to afford mixtures of the expected Baylis-Hillman products and unprecedented dimeric derivatives. The Baylis–Hillman products, on heating at 80°C in the presence of DABCO, are converted to the corresponding dimers, the structures of which have been unambiguously established by NMR and X-ray crystallographic analysis. Electron-impact and electrospray MS data for the dimeric systems are discussed.