Synthesis and chemical reactivity of novel pyrano[3,2-<i>c</i>]quinoline-3-carbonitriles

Ibrahim, Magdy A.; Badran, Al‐Shimaa

doi:10.1080/00397911.2020.1759095

Cited by 9 publications

(1 citation statement)

References 36 publications

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“…11 Chromone-3-carbonitrile are essential source for building of chromeno [2,3-b]pyridines through their reactions with active methylene compounds. 12 The present work aimed to utilize ethyl 2,5-dioxo-1,5dihydro-2H-chromeno [2,3-b]pyridine-3-carboxylate ( 2) 13 for construction of some novel chromeno [2,3b]pyridines bearing variable heterocyclic systems at position 3.…”

Section: Introductionmentioning

confidence: 99%

Synthetic Approaches for Construction of Novel 3-Heteroarylchromeno[2,3-b]pyridines and Annulated Chromenopyridopyrazolopyrimidines

Ibrahim¹,

Alnamer²

2021

HETEROCYCLES

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Hydrazinolysis of ethyl 2,5-dioxo-1,5-dihydro-2H-chromeno[2,3-b]pyridine-3-carboxylate (2) afforded chromeno[2,3-b]pyridine-3-carbohydrazide 3 which utilized as a precursor for building a diversity of heterocyclic compounds at position 3. Condensation of carbohydrazide 3 with 3-formylchromone produced the condensation product 4, while addition of carbohydrazide 3 to phenylisothiocyanate gave hydrazinecarbothioamide derivative 5 which upon cyclization afforded 3-thiadiazolchromeno[2,3-b]pyridine-2,5(1H)-dione 6. Condensation of carbohydrazide 3 with some monoelectrophilic reagents namely ethyl chloroformate, carbon disulfide, acetyl chloride and benzoyl chloride and chromone-3-carboxylic acid gave a variety of novel 3-oxadiazolylchromeno-[2,3-b]pyridines 7-10 and 12. Treatment of carbohydrazide 3 with a variety of 1,3-bielectrophiles such as acetylacetone, ethyl acetoacetate and diethyl malonate yielded 3-(pyrazolyl)carbonylchromeno[2,3-b]pyridines 13-15. Finally, reaction of carbohydrazide 3 with ethyl cyanoacetate and (ethoxymethylene)malononitrile afforded heteroannulated chromeno[2``,3``:6`,5`]pyrido[2`,3`-d]pyrazolo[1,5-a]pyrimidines 17 and 18. Structures of the synthesized products were confirmed based on their analytical and spectral data.

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Section: Introductionmentioning

confidence: 99%