A one‐pot synthesis of the 1‐benzopyrano[2,3‐b]pyridine moiety from 2‐(alkyl/arylamino)‐4‐oxo‐4H‐1‐benzopyran‐3‐carbaldehyde

Abstract

magnified image 2‐(Alkyl/arylamino)chromone‐3‐carbaldehyde reacts with Meldrum's acid, hippuric acid, 4‐hydroxycoumarin, diethyl malonate, ethyl acetoacetate, or ethyl benzoylacetate to produce 1‐benzopyrano[2,3‐b]pyridine‐2,5‐dione moiety, but ethyl cyanoacetate and malononitrile react differently. J. Heterocyclic Chem., (2010).

Chemistry of 2-amino-4-oxo-4H-1-benzopyran-3-carboxaldehydes

“…4,5 N,N-dimethylacetamide dimethyl acetal 155 and 1-methylpyrrolidine-2-one diethyl acetal 156 give with 1 the condensed products 154 and 157, respectively. 65 Maiti et al 66 have extensively studied the condensation of 2-(monosubstituted amino)-3-formylchromone 2 with several active methylene compounds. Condensation of 2 with Meldrum's acid, ethyl acetoacetate, ethyl benzoylacetate, diethyl malonate and hippuric acid gives pyranopyridones 158a-e, respectively.…”

Convenient variant of the synthesis of 5-oxo-4,5-dihydro-1h-[1,2,3]triazolo[4,5-b]pyridine-6-carboxylic acid

“…Зокрема, ІЧ-спектри характеризуються смугами валентних коливань груп NH (3142−3154 см -1 ); С=О (1707-1725 см -1 ); СООН (2645−2884 см -1 ). Вагомим доказом формування у процесі циклізації піридинового ядра є наявність у спектрах ЯМР 1 Н синглетів сигналів протонів Н 7 у діпазоні 8,42−9,04 м.д., а в спектрах ЯМР 13 С -п'яти сигналів зазначеного циклу.…”

A One-Pot Rearrangement of 2-(N-Alkyl-N-aryl)aminochromone-3-carbaldehyde to N-Alkyl-3-salicyloyl-2-quinolone - An Antileishmanial Agent

“…14 Latterly, we have utilized 3 for the synthesis of bischromones involving a deformylative Mannich reaction, 15 to prepare chromeno[2,3-b]pyridines with varying substituents at their 3-position. 16 2-(N-allyl-N-aryl)aminochromone-3-carbaldehyde has also been used for intramolecular [3+2]-nitrone cycloaddition reaction at low temperature involving N-methylhydroxylamine, 17 while we have utilized the same compound for intramolecular [3+2]-azomethine ylide cycloaddition reaction 18 and for domino Knoevenagel-hetero Diels-Alder reaction. 19 Different methods for the synthesis of the 2-quinolone moiety have been reported.…”