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.

Dr.Subashini Rajagopal

VIT Business School

Chennai Campus

Sumathi S

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Subbareddy C.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

Molecular Diversity

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.

Journal of Molecular Liquids

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

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.

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 newly synthesized 4-(1H-indol-3-yl)-2-methyl-N-phenyl-4H-chromene-3-carboxamide derivatives catalyzed by 1,4-Diazabicyclo [2.2.2]octane (DABCO) (30 mol%) at room temperature.

New Journal of Chemistry

One-pot three-component protocol for the synthesis of indolyl-4H-chromene-3-carboxamides as antioxidant and antibacterial agents

Microwave-assisted montmorillonite K-10-catalyzed Friedlander synthesis of quinolinylquinolinones has been developed. The efficient and eco-friendly catalyst along with the convenience of the product isolation make this process an attractive alternative for the synthesis of target heterocycles. The synthesized products were confirmed by FTIR, 1H NMR, 13C NMR, and mass spectroscopic techniques. All the synthesized compounds showed good antibacterial property similar to standard Ampicillin and enhanced antioxidant activity. © 2014 Springer Science+Business Media Dordrecht.

Research on Chemical Intermediates

Microwave-assisted solid acid-catalyzed synthesis of quinolinyl quinolinones and evaluation of their antibacterial, antioxidant activities

An efficient strategy for the synthesis of 3-acetyl-2-methyl-1-phenylisochromeno [4,3-b] pyrrol-5(1H)-ones 4a–f have been developed using montmorillonite K10 as a catalyst. The synthesized compounds have prominent antioxidant activity and fluorescence properties.

RSC Adv.

Fluorescent and antioxidant studies of effectively synthesized isochromenopyrrolone analogues

Letters in Organic Chemistry

A Green Synthesis and a Chemical Study of the Coumarin, 1-(2-Hydroxy- 2-methyl-2H-chromen-3yl)ethanone

Materials Science-Poland

Quantum chemical studies on the molecular structure, spectroscopic and electronic properties of (6-Methoxy-2-oxo-2H-chromen-4-yl)-methyl pyrrolidine-1-carbodithioate

Journal	Data powered by TypesetMolecular Diversity
Publisher	Data powered by TypesetSpringer Science and Business Media LLC
ISSN	1381-1991
Open Access	0