AbstractThe Mitsunobu reaction is a well-established fundamental reaction and has been widely applied in organic synthesis. In this paper, under Mitsunobu conditions dehydration proceeds between (2-chloroquinolin-3-yl)methanol and nitrogen heterocyclic compounds such as quinazolinone, pyrimidone, 2-oxoquinoline in dry THF in the presence of triethylamine, triphenylphosphane and diethyl azodicarboxylate to give the corresponding products. As part of our recent research, we attempted to couple two N-heterocyclic compounds under Mitsunobu reaction conditions to provide efficient building blocks for natural product synthesis.

Mohana Roopan S

Department of Chemistry

School of Advanced Sciences

Vellore Campus

Nawaz Khan F

Jin J.S.

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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Chemical Papers

A new and highly efficient microwave promoted N-alkylation of triazolo-quinazolinones was developed by treating various phenyl-substituted heterocyclic amines with benzyl chloride using K2CO3 as a base in the presence of DMF. Also the heterocyclic amines were synthesized by condensing the 3-amino-1,2,4-triazole substituted benzaldehydes and 1,3-cyclohexanedione in the presence of microwave irradiation under solvent free condition. The synthesized heterocycles 4a–o and 6a–o were further confirmed by using different spectroscopic techniques such as NMR and HRMS. The compounds 6a–o was studied for their solvatochromic property with increasing polarity of solvents. The determinations of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging effect of the scaffolds 6a–o were carried out by UV–Vis spectrometer. In terms of IC50 all the compounds have shown remarkable antioxidant property compared with Ascorbic acid. © 2016 Elsevier B.V.

Journal of Molecular Liquids

Conventional spectroscopic identification of N-alkylated triazolo-quinazolinones and its antioxidant, solvatochromism studies

A non-conventional methodology has been utilized for the synthesis of a series of 1,2,4-triazolo-quinazoline-thiones (2a-l). Here the reaction was carried out between 1,2,4-triazolo-quinazolinones (1a-l), in the presence of 1,4-dioxane. The mixture was irradiated under microwave (100W) for 7min to obtain targeted molecules (2a-l). All the synthesized molecules were confirmed by (1)H, (13)C NMR and HRMS. The solvatochromic property (absorption spectra) of compounds (2a-l) in solvents of different polarities was studied. The compounds (2a-l) were further subjected for their in vitro free radical screening using 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and also screened for their in vitro anti-fungal property against Aspergillus flavus (A. flavus) and Aspergillus niger (A. niger). The results from free radical scavenging assay showed promising activity for compounds 2a, e-i, whereas compound 2d showed significant antioxidant activity when compared to ascorbic acid. In vitro anti-fungal study showed that the 1,2,4-triazolo-quinazoline-thiones (2a-l) had significant activity against A. flavus and A. niger compared with widely used antifungal agent Fluconazole.

Journal of Photochemistry and Photobiology B: Biology

1,2,4-Triazolo-quinazoline-thiones: Non-conventional synthetic approach, study of solvatochromism and antioxidant assessment

A series of 6,7-dihydro-[1,2,4]triazolo[5,1-b]quinazolin-8(5H)-ones, 4a–o were synthesized via a one-pot, multicomponent reaction in the presence of water as a solvent under microwave irradiation using ceric ammonium nitrate as an oxidizing agent. This techno-chemical method provides a rapid construction of higher molecules in short duration with high yield. The adopted method was carried out in the presence of water without catalyst and yielded the compounds without any side products, and thus further purification of compounds by column chromatography was not required. All the synthesized compounds, 4a–o were screened for their 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. All the compounds, 4a–o possessed moderate antioxidant activity when compared to their standard antioxidant (ascorbic acid). © 2015, Springer Science+Business Media Dordrecht.

Research on Chemical Intermediates

Microwave assisted synthesis of ring junction heterocyclic antioxidants

An efficient and regioselective N-alkylation of 4(3H)-pyrimidone with various electrophiles in the presence of Fe nano particle is reported. The catalyst initiates N-alkylation of amides by alkyl chlorides. The reaction of equimolar 4(3H)-pyrimidone and 2-chloro-3-(chloromethyl)quinolines in the presence of KOH and Fe nano particle (5 mol %) in DMSO solution under reflux condition formed 3-[(2-chloroquinolin-3-yl]methyl)pyrimidin-4(3H)ones. © 2010 Elsevier Ltd. All rights reserved.

Tetrahedron Letters

Fe nano particles mediated C–N bond-forming reaction: Regioselective synthesis of 3-[(2-chloroquinolin-3-yl)methyl]pyrimidin-4(3H)ones

All the non-H atoms of the title compound, C11H 10ClNO2, are roughly coplanar (r.m.s. deviation = 0.058 Å). In the crystal, adjacent mol-ecules are linked by an O-H⋯N hydrogen bond, generating chains running along the a axis.

Fulltext

Acta Crystallographica Section E Structure Reports Online

2-Chloro-3-hydroxymethyl-6-methoxyquinoline

All non-H atoms of the title compound, C12H12ClNO, are co-planar (r.m.s. deviation = 0.055 Å). The hydroxy H atom is disordered over two positions of equal occupancy. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, generating zigzag chains running along the b axis.

2-Chloro-3-hydroxymethyl-7,8-dimethylquinoline

AbstractFor the first time, synthesis of AB ring core of camptothecin synthons such as (2-chloroquinolin-3-yl)methanols (Va-Vg) using zinc oxide nanoparticles is reported. The desired attractive products were obtained in high yields, short reaction time, using a simple work-up procedure with the purification of products by non-chromatographic methods.

ZnO nanoparticles in the synthesis of AB ring core of camptothecin

In the title compound, C18H14ClNO3, the dihydro-quinolin-2-one ring system is almost planar (r.m.s. deviation = 0.033 Å). The carboxyl-ate plane and the phenyl group are twisted away from the dihydro-quinolin-2-one ring system by 50.3 (1) and 64.9 (1)°, respectively. In the crystal structure, inversion-related mol-ecules form R 2 2(8) dimers via pairs of N - H⋯O hydrogen bonds.

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ISSN	03666352
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