Ajinkya A. Patravale

Contemporary development in sequential Knoevenagel, Michael addition multicomponent reaction for the synthesis of 4-Aryl-5-oxo-5H-indeno[1,2-b]pyridine-3-carbonitrile

An uncatalyzed efficient synthesis of bioactive pyridine derivatives has been investigated for the first time by a three-component sequential multicomponent reaction tackled with aromatic aldehydes, malononitrile, and 1,3-indandione via Knoevenagel condensation followed by Michael addition. The difference between the domino multicomponent and sequential multicomponent reaction is emphasized by this methodology. The reaction proceeds at ambient temperature without frequently useful N-source like ammonium salt for the construction of N-heterocycles, which makes this protocol a novel synthetic route for the preparation of the indenopyridine skeleton.Graphical Abstract

Synthesis, anti-inflammatory, ulcerogenic and cyclooxygenase activities of indenopyrimidine derivatives.

Objective of the present work was to evaluate the anti-inflammatory, ulcerogenicity and cyclooxygenase activity of indenopyrimidine derivatives. Anti-inflammatory activity of the tested compounds is investigated by carrageenan-induced rat paw edema assay. Compounds A1, A6, A7 and A12 exhibit the comparable anti-inflammatory activity (79.33-81.33%) to the standard drug diclofenac sodium (85.33%), while A6, A7, A9, A12 and A14 show better ulcer index than the reference standard diclofenac sodium. To rationalize the anti-inflammatory activity, docking experiments are performed to study the ability of these compounds to bind into the active site of COX-2 enzyme.

Sulfamic acid-catalyzed multicomponent synthesis of 7-phenyl-7,12 dihydrobenzo(h)pyrido[2,3-b]naphthydrin-6(5H)-one derivatives: a green avenue

A series of novel 7-phenyl-7,12-dihydrobenzo(h)pyrido[2,3-b]naphthydrin-6(5H)-one were synthesized by a one-pot three-component condensation of 2,4-dihydroxyquinoline, 2-amino pyridine and various aromatic aldehydes with sulfamic acid as an enviro-economic catalyst. The salient features of this method consist of high atom economy and yields, short reaction time, non-carcinogenic solvents, and chromatography-free work-up procedure. Fascinatingly, the catalyst can be reused for up to four cycles giving good to excellent yields. By employing this method, a series of 14 pyrido[2,3-b]naphthydrin compounds were synthesized. This procedure is projected as a green avenue in the combinatorial synthesis of biologically active naphthydrin derivatives.Graphical Abstract

(±)-Camphor-10-sulfonic acid as recyclable and efficient catalyst for the synthesis of some novel coumarin derivatives

ABSTRACT A highly competent-diversity oriented synthesis of coumarin core derivatives using a Knoevenagel condensation followed by Michael addition and subsequent cyclization in the presence of (±)-camphor-10-sulfonic acid in a water/ethanol (1:1) solvent system is depicted. Furthermore, easy workup procedures with good yield, rapid reactions with high atom economy, and catalyst recyclability are the fascinating features of the procedure. GRAPHICAL ABSTRACT

Low transition temperature mixtures prompted one-pot synthesis of 5, 10 dihydropyrimido[4,5-b]quinoline-2,4(1 H ,3 H )-dione derivatives

An efficient green protocol has been investigated for the synthesis of pyrimido[4,5-b]quinolines derivatives via one-pot three-component condensation of 4-chloro aniline, aromatic aldehyde and barbituric acid using low transition temperature mixtures as new generation and sustainable solvents. The process was accomplished with the use of greener and recyclable reaction media, simple methodology, easy workup procedures and no chromatographic purification with high yield. This new approach is expected to discover some significance in combinatorial synthesis of biologically active scaffolds.Graphical Abstract

Target Oriented Selective Synthesis of Antibacterial Active Tyrosinase Enzyme Inhibitor Coumarin Core Derivatives

Target oriented designs and selective synthesis of bioactive molecules with broad spectrum activity is a challenging job in the field of modern organic chemistry. Considering this opportunity herein, we report a highly competent selective synthesis of bioactive coumarin core derivative. Using computational drug design software only four selective antibacterial active derivatives was discovered and then synthesized. The efficiency of the synthesized compounds was scrutinized against bacterial pathogens such as P. vulgaris and B. megaterium. All the synthesized compounds showed better theoretical as well as practical results against selected pathogenic species. The minimum inhibitory concentration (MIC) values of the most active heterocycles were compared with that of ciprofloxacin. Results obtained in tyrocinase inhibition assay exactly correlate with MIC results and docking outcomes. The bioactivity of these type moieties provided a novel approach to develop new types of antibacterial drugs like entities effective against pathogens.