Dyal Singh College

Sultānpur Lodhi, India

Dyal Singh College

Sultānpur Lodhi, India
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Neena,Dyal Singh College | Neena,Sudan University of Science and Technology | Nain S.,Sudan University of Science and Technology | Bhardwaj V.,Kurukshetra University | Kumar R.,Dyal Singh College
Pharmaceutical Chemistry Journal | Year: 2015

Efficient synthesis of a series of pyrazolylbiscoumarin (4a – 4e) and pyrazolylxanthenedione derivatives (5a – 5e) is described. The structures of the synthesized compounds were confirmed by their spectral data (IR, 1HNMR and 13CNMR). All the synthesized compounds 4 and 5 were screened for their antibacterial activity against Gram-positive bacteria S. aureus and Gram-negative bacteria K. pneumoniae. The tested compounds exhibited varying degree of antibacterial activity, showing the inhibition zone size ranging from 6 to 21 mm. © 2015, Springer Science+Business Media New York.


Tejpal H.,Dyal Singh College | Chaudhary B.S.,Kurukshetra University
Transactions of the Institute of Indian Geographers | Year: 2014

Accelerated developmental activities during the past few decades have imposed immense pressure on rivers which functions as life support systems. As a result, many river channels in the world have been altered drastically to the level beyond their natural resilience capacity. Among various types of human interventions, indiscriminate extraction of sand and gravel is most disastrous one, as it threatens the very existence of the riverine ecosystem. The present study examines the impact of sand and stone extraction on land and groundwater resources in the Narnaul Block ofHaryana. For this purpose, areal expansion ofsand and stone quarries and their impacts on local ecology in the study area have been examined using geo-spatial techniques. Images captured by Landsat 1 MSS and Landsat 7 ETM+ satellites between 1975 and 2009 have been used for the analysis. Changes in the natural vegetation as a function of the production level in the quarries have been computed using the normalized difference vegetation index. It is revealed that the vegetated areas have decreased rapidly between 1975 and2009following an upsurge in sand and stone mining activity in the region. In addition, excessive extraction of construction material has accelerated the decline in the groundwater level, particularly in the Dohan river catchment part of the study area in recent years. The construction boom has fueled the demand whereas weak governance and rampant corruption have facilitated hysterical and illegal mining of construction material from the dry river channels threatening ecology.


Li S.-C.,Tulane University | Losovyj Y.,Louisiana State University | Paliwal V.K.,Tulane University | Paliwal V.K.,Dyal Singh College | And 2 more authors.
Journal of Physical Chemistry C | Year: 2011

The electronic structure of azobenzene and aniline, adsorbed on two TiO2 surfaces, anatase (101) and rutile (110), has been studied with ultraviolet synchrotron-based photoemission spectroscopy (UPS). At saturation coverage, azobenzene and aniline exhibit very similar molecular orbitals in UPS valence band spectra. Angle-resolved UPS exhibits anisotropy of the molecular states along the polar and azimuthal direction, as is expected for highly oriented superstructures. For a low coverage of azobenzene adsorbed on anatase, photon irradiation results in the conversion of the flat-lying molecule into two upright phenyl imide species. An irradiation-induced trans-cis isomer conversion is proposed to facilitate the azobenzene cleavage. These results confirm that the N=N double bond of azobenzene is cleaved by TiO2 in the fullcoverage regime and that the resulting intermediate is bonded to the substrate, in agreement with a previous scanning tunneling microscopy study and a proposed reaction scheme for azobenzene ↔ aniline conversion at TiO 2 surfaces [Li, S.-C.; Diebold, U. J. Am. Chem. Soc. 2010, 132, 64]. © 2011 American Chemical Society.


Kumar R.,Kurukshetra University | Kumar R.,Dyal Singh College | Prakash O.,Kurukshetra University
Heterocyclic Communications | Year: 2010

Synthesis of some new heterocyclic derivatives 3a-3g has been reported by the condensation of suitable reagents with malondialdehyde 2. The malondialdehyde 2 was synthesized by Beckmann rearrangement of 2-hydroxy-5-methylacetophenone oxime 1 using Vilsmeier-Haack reagent (POCl 3/ DMF), followed by cyclization.


Prakash O.,Kurukshetra University | Aneja D.K.,Kurukshetra University | Wadhwa D.,Kurukshetra University | Kumar R.,Dyal Singh College | Arora S.,Kurukshetra University
Journal of Heterocyclic Chemistry | Year: 2012

The synthesis of a series of 21 novel 3-alkyl/aryl-7/9-methyl-10,10a- dihydroindeno[1,2-e][1,2,4]triazolo[3,4-b][1,3,4]thiadiazines (4) has been achieved by the cyclocondensation between 4/6-methyl-2-tosyloxy-1-indanones (2) and 3-alkyl/aryl-4-amino-5-mercapto-1,2,4-s-triazoles (3). 4/6-Methyl-2- tosyloxy-1-indanones (2) were readily accessible through hypervalent iodine oxidation of 4/6-methyl-1-indanones using [(hydroxy)tosyloxyiodo]benzene (HTIB, Koser's reagent) in acetonitrile. © 2012 Hetero Corporation.


Prakash O.,Kurukshetra University | Wadhwa D.,Kurukshetra University | Hussain K.,Kurukshetra University | Kumar R.,Dyal Singh College
Synthetic Communications | Year: 2012

Facile synthesis of furo[3,2-c]coumarins (2a-g) via cyclocondensation of 4-hydroxycoumarin and-tosyloxyketones (1a-g) is described. A plausible mechanism involving C-C bond formation followed by 5-exo-tet cyclization is suggested. © 2012 Taylor & Francis Group, LLC.


Kumar R.,Dyal Singh College | Wadhwa D.,Kurukshetra University | Hussain K.,Kurukshetra University | Prakash O.,Kurukshetra University
Synthetic Communications | Year: 2013

A modified protocol for diastereoselective synthesis of differently substituted trans-2,3-dihydrofuro[3,2-c]coumarins is developed via, a one-pot multicomoponent reaction starting from aromatic aldehydes, 4-hydroxycoumarin, and α-tosyloxyacetophenones with pyridine and triethylamine as catalysts. The developed protocol provides a better alternative to the existing methods as it involves utilization of α-tosyloxyacetophenones that may be generated in situ from acetophenones and [hydroxyl(tosyloxy)iodo]benzene (HTIB, Koser's reagent), avoiding the use of α-haloacetophenones. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. © 2013 Taylor and Francis Group, LLC.


Singh D.,Dyal Singh College | Jaggi N.,National Institute of Technology Kurukshetra | Singh N.,Kurukshetra University
Indian Journal of Physics | Year: 2010

The organic compound 1-chlorooctane exists in liquid state at ambient temperatures and has numerous synthetic applications. Fourier transform infrared and Raman spectra of this molecule have been recorded in the range of 4000-400 cm-1 and 3500-200 cm-1, respectively. A detailed vibrational analysis in terms of assignment of the observed frequencies of this molecule for its four most probable conformations in liquid phase, having symmetries Cs and Cl, has been done using normal co-ordinate calculations. The force-field transferred from already studied lower chain chloro-alkanes is subjected to refinement so as to fit the observed infrared and Raman frequencies with those of calculated ones. The potential energy distribution has also been calculated for each mode of vibration of the molecule for the most probable conformations present in its liquid phase. © 2010 IACS.


Singh D.,Dyal Singh College | Jaggi N.,National Institute of Technology Kurukshetra | Singh N.,Kurukshetra University
Indian Journal of Physics | Year: 2010

The organic compound 1,8-dibromooctane (1,8-DBO) exists in liquid phase at ambient temperatures and has versatile synthetic applications. In its liquid phase 1,8-DBO has been expected to exist in four most probable conformations, with all its carbon atoms in the same plane, having symmetries C 2h, C 1, C 2 and C 1 In the present study a detailed vibrational analysis in terms of assignment of Fourier transform infrared (FT-IR) and Raman bands of this molecule using normal co-ordinate calculations has been done. Asystematic set of symmetry co-ordinates has been constructed for this molecule and normal co-ordinate analysis Is carried out using the computer program MOLVIB. The force-field transferred from already studied lower chain bromo-alkanes is subjected to refinement so as to fit the observed infrared and Raman frequencies with those of calculated ones. The potential energy distribution (PED) has also been calculated for each mode of vibration of the molecule for the assumed conformations. ©2010 IACS.


PubMed | Dyal Singh College
Type: Journal Article | Journal: Organic and medicinal chemistry letters | Year: 2012

Dialkyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylates (1,4-DHP) have now been recognized as vital drugs. Some of these derivatives such as amlodipine, felodipine, isradipine, etc. have been commercialized. In view of wide range of biological properties associated with 1,4-DHP and owing to the biological importance of the oxidation step of 1,4-DHP, we carried out the synthesis and antimicrobial evaluation of new diethyl 1,4-dihydro-2,6-dimethyl-4-(3-aryl-1-phenyl-4-pyrazolyl)pyridine-3,5-dicarboxylates (2a-g) and diethyl 2,6-dimethyl-4-(3-aryl-1-phenyl-4-pyrazolyl)pyridine-3,5-dicarboxylates (3a-g).Synthesis of a series of new diethyl 1,4-dihydro-2,6-dimethyl-4-(3-aryl-1-phenyl-4-pyrazolyl)pyridine-3,5-dicarboxylates (2a-g) has been accomplished by multicomponent cyclocondensation reaction of ethyl acetoacetate, 3-aryl-1-phenyl pyrazole-4-carboxaldehyde (1a-g) and ammonium acetate. The dihydropyridines 2a-g were smoothly converted to new diethyl 2,6-dimethyl-4-(3-aryl-1-phenyl-4-pyrazolyl)pyridine-3,5-dicarboxylates (3a-g) using HTIB ([Hydroxy (tosyloxy)iodo]benzene, Kosers reagent) as the oxidizing agent. The antimicrobial studies of the title compounds, 2a-g &3a-g, are also described.

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