Synthesis and Antimicrobial Evaluation of New Pyrano[4,3‐b]pyran and Pyrano[3,2‐c]chromene Derivatives Bearing a 2‐Thiophenoxyquinoline Nucleus

Abstract

A new series of pyrano[4,3-b]pyran 4a-i and pyrano[3,2-c]chromene 6a-r derivatives bearing a 2-thiophenoxyquinoline nucleus were synthesized by reaction of 2-(4-(un)-substituted thiophenoxy)quinoline-3-carbaldehydes 2a-i with 6-methyl-4-hydroxypyran-2-one 3 and 4-hydroxy-6-(un)-substituted-2H-chromen-2-one 5a-b respectively and malononitrile at room temperature in the presence of KOH as a basic catalyst. All the compounds were screened against three Gram-positive bacteria (Streptococcus pneumoniae, Bacillus subtilis, Clostridium tetani), three Gram-negative bacteria (Salmonella typhi, Escherichia coli, Vibrio cholerae) and two fungi (Candida albicans, Aspergillus fumigatus) using the broth microdilution MIC (minimum inhibitory concentration) method. Upon antimicrobial screening, it was observed that the majority of the compounds were found to be active against Bacillus subtilis, Clostridium tetani and Candida albicans as compared to standard drugs.

Triaminopyrimidine Based Porous Organic Polymers: Synthesis, Characterization and Catalytic Applications in One‐pot Room Temperature Synthesis of Dihydropyranopyranes

“…Likewise fused pyranes are important oxygenated heterocyclic compounds which also exhibit a wide range of biological activities (Figure ) such as anticonvulsant, antiviral,– antimicrobial, antiproliferative, antitumor, antituberculor, mutagenic, insecticidal and sex pheromone activities . Also, many of them are non‐peptide human immunodeficiency virus (HIV) protease inhibitors –.…”

Bridged Alkyl Ionic Liquid‐Catalyzed Tandem Reaction for Synthesis of Spiro[4H‐pyran‐3,3′‐oxindoles] in Aqueous Ethanol Solution

“…Similar to spirooxindoles, the heterocyclic scaffold of 2‐amino‐4 H ‐pyrans are the key core in many natural products, pigments, fluorescence markers and photochromic materials . These compounds demonstrate a wide range of biological and pharmacological activities, such as anticancer, antioxidant, antiinflammatory, antimicrobial, and antihyperglycemic properties . A glimpse of some structures of spirooxindoles and 2‐amino‐4 H ‐pyrans are shown in Figure .…”

Synthesis of Ethyl 2‐Amino‐4‐benzoyl‐5‐oxo‐5,6‐dihydro‐4H‐pyrano[3,2‐c]quinoline‐3‐carboxylates by a One‐pot, Three‐Component Reaction in the Presence of TPAB

“…Substantial characteristics of pyran such as antimicrobial , anticancer , antidyslipidemic , antihyperglycemic , anti‐HIV , antioxidant , antiallergic , xanthine oxidase inhibitory , acetylcholinesterase and butyrylcholinesterase inhibitory , and Src kinase inhibitory activities in addition to its presence in nature, making pyran derivatives specific structures.…”