A novel 4H-chromene-3-carboxamide derivatives were synthesized from a multicomponent reaction between 2-hydroxybenzaldehyde, acetoacetanilide, and 4-hydroxycoumarin under solvent free conditions in the presence of ceric ammonium nitrate (CAN) via Knoevenagel-Michael reaction. In this work, we attempted and developed several amendments under solvent-free conditions to obtain the biologically important 4H-chromene-3-carboxamides and characterized by NMR, HR-MS and UV–Vis spectroscopy analysis. The solvatochromic properties of compounds 4a–l was studied with solvents of increasing order of polarity. A series of 4H-chromene-3-carboxamides 4(a–l) and their antibacterial activities against Gram positive and Gram negative organisms was investigated using agar well technique. In the in vitro assay, the compounds 4k and 4l (9.3 μg/mL) showed promising antibacterial activity compared to ampicillin (standard). The compounds 4(a–l) were studied for their in vitro antioxidant (DPPH method) activity, 4d, 4h, 4k, and 4l compounds showed strong antioxidant activity with IC50 values of 1.39, 1.33, 1.26 and 1.10 μg/mL when compared to ascorbic acid (standard). © 2017 Elsevier B.V.

Sumathi S

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Chitreddy S.V

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Journal of Molecular Liquids

In the present work, we have designed and synthesized novel indolyl-4H-chromene-phenylprop-2-en-1-one derivatives (5a–o) using Amberlite SR1L Na (150 mg) as catalyst at 60 °C in DMSO. For the first time, a series of 2-alkoxy-2H-chromen chalcones (3a–h) are prepared by reacting 1-(2-ethoxy-2-methyl-2H-chromen-3yl)ethan-1-one with various substituted aldehydes in the presence of 20% ethanolic sodium hydroxide. After optimizing the reaction conditions, the synthesized chalcones (3a–h) were further reacted with various indoles (4a–b) via regioselective nucleophilic substitution to yield the corresponding derivatives (5a–o) in excellent yields by C[sbnd]C coupling reaction and confirmed by 1H, 13C NMR HRMS and UV–Visible spectroscopy analysis. The employed synthetic route offered several advantages such as simple reaction conditions, easy handling, short reaction time, environmentally benign, and reusability of the catalyst. The synthesized compounds (5a–o) was studied for their solvatochromic property with increasing polarity of solvents. The compounds (5a–o) were evaluated for their antioxidant activity by free radical screening using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) method. Also, their in-vitro antibacterial activity has been investigated against gram positive (S. aureus and B. subtilis) and gram negative bacteria (Klebsiella and E. coli) by agar well technique. Among the compounds employed, 5g and 5h not only showed promising antioxidant activity but also significant antibacterial activity against S. aureus compared to the experimental standards. © 2017 Elsevier B.V.

Synthesis, antioxidant, antibacterial, solvatochromism and molecular docking studies of indolyl-4H-chromene-phenylprop-2-en-1-one derivatives

Solvent free-synthesis of highly functionalized 4H-chromene-3-carboxamide derivatives using cerium ammonium nitrate and their antioxidant, antibacterial and solvatochromism studies

A series of alkoxy-substituted 2H-chromenes were synthesized by a one-pot three-component reaction using salicylaldehydes, acetyl acetone and alcohol as reactant and medium with tetra-n-butylammonium fluoride (TBAF) as catalyst. Simple reaction conditions, short reaction time and overall good yield of products make this synthetic strategy an efficient one to synthesize 2H-chromene molecules. All the synthesized compounds were evaluated for antioxidant activities. Among all the new compounds, 5j and 5k showed good inhibition [Formula: see text] and [Formula: see text]) at 100 [Formula: see text] concentrations.

Molecular Diversity

Synthesis of substituted 2H-chromenes by a three-component reaction as potential antioxidants

A series of 2-(3,5-substituted-1H-pyrazol-1-yl)-3-substituted quinolines 5a–g, were obtained from 2-chloro-3-(1,3-dioxolan-2-yl) quinolines 2a–c and diketones 3a–c with great yields by utilizing Montmorillonite clay K-10 as a catalyst in an eco-friendly methodology. All the synthesized compounds were characterized by FTIR, 1H-NMR, 13C-NMR and HRMS spectral techniques. Antibacterial screening of the compounds revealed that some of the compounds demonstrate moderate to good results. Amongst all, compound 2c displayed a good inhibitory profile against P. aeruginosa and B. subtilis, while compound 5c exhibited remarkable activity against S. aureus, B. subtilis and P. aeruginosa with an MIC value of 25 μg mL−1. Moreover, compound 5c presented a MIC value of 50 μg mL−1 against E. coli and K. pneumoniae, which was comparable to that of the standard. In addition, compound 5f was demonstrated good viability against S. aureus and P. aeruginosa with a MIC value of 25 μg mL−1. Compounds 2c and 5f, however, showed relatively moderate inhibition against S. aureus, while the latter had a moderate activity against B. subtilis. To further demonstrate the antibacterial efficacy of 2c, 5c and 5f, molecular docking studies were done, confirming that compound 5c possesses good binding interaction with the peptide deformylase protein, with a binding energy of −8.1 kcal mol−1—more prominent than that of standard ampicillin (−7.5 kcal mol−1)—while compounds 2c and 5f have moderate binding affinity.

RSC Adv.

Potential anti-bacterial agents: montmorillonite clay-catalyzed synthesis of novel 2-(3,5-substituted-1H-pyrazol-1-yl)-3-substituted quinolines and their in silico molecular docking studies

Journal	Data powered by TypesetJournal of Molecular Liquids
Publisher	Data powered by TypesetElsevier BV
ISSN	0167-7322
Open Access	0