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Chemical behavior of 4, 9‐dimethoxy‐5‐oxo‐5 H ‐furo[3,2‐ g ]chromene‐6‐carboxaldehyde towards carbon nucleophilic reagents
Author(s) -
Ibrahim Magdy A.,
ElGohary Nasser M.
Publication year - 2020
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.3991
Subject(s) - chemistry , malononitrile , pyridine , nucleophile , methylene , reagent , ring (chemistry) , aldehyde , cyanoacetamide , medicinal chemistry , benzimidazole , organic chemistry , stereochemistry , catalysis
The chemical behavior of 6‐formylkhellin ( 1 ) was investigated toward a variety of carbon nucleophiles. Treatment of aldehyde 1 with cyanoacetamide, N ‐benzylcyanoacetamide produced pyridine‐3‐carboxamides 3 and 4 . Treatment of carboxaldehyde 1 with malononitrile dimer and 1 H ‐benzimidazol‐2‐ylacetonitrile gave 1,6‐naphthyridine 5 and pyrido[1,2‐ a ]benzimidazole 6 , respectively. Some novel pyrazolo[3,4‐ b ]pyridine 7 , pyrido[2,3‐ d ]pyrimidines 8 and 9 were synthesized from the ring opening ring closure reactions of carboxaldehyde 1 with certain heterocyclic enamines. In addition, reaction of carboxaldehyde 1 with certain cyclic enols produced a variety of products. Treatment of carboxaldehyde 1 with 1,3‐cyclohexanediones gave xanthene‐1,8‐diones 19 and 20 . Reaction of carboxaldehyde 1 with 5‐methyl‐2,4‐dihydro‐3 H ‐pyrazol‐3‐one proceeds in 1:2 M ratio producing pyrazolo [4′,3′:5,6]pyrano[2,3‐ c ]pyrazole derivative 22 . Carboxaldehyde 1 reacted with certain heterocyclic compounds containing active methylene groups to give the corresponding condensation products 22 ‐ 27 . The synthesized compounds were screened in vitro for their antimicrobial activity and showed high to moderate activities against the tested microorganisms.