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IJCRR - 5(11), June, 2013

Pages: 01-09

Date of Publication: 18-Jun-2013

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BENZOPHENONE SENSITIZED ONE-POT PHOTOREDOX REACTION OF N-(Α-CYANO-Α-SUBSTITUTED PHENYL)-METHYLANILINES LEADING TO THE SYNTHESIS OF BENZOIMIDAZOLOQUINOLINES

Author: Manpreet Kaur, Baldev Singh

Category: General Sciences

Abstract:N-(\a-cyano-\a-substituted phenyl)-methylanilines (I) on exposure to bright sunlight using soda glass photoreactor are transformed smoothly, with insertion of one methylene group from the solvent (methanol), into substituted benzoimidazoloquinolines (II) with improved yields under benzophenone sensitized conditions employing basic aqueous alcoholic medium in the presence of iodide salt. These compounds have been characterized through their, elemental analysis, IR, 1H NMR, 13C NMR and mass spectral studies.

Keywords: Azomethines, N-(?-cyano-?-substituted phenyl)-methylanilines, benzophenone

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INTRODUCTION
Upon exposure with ultraviolet radiations organic nitriles have provided a variety of new heterocyclic compounds depending on the reaction conditions employed[1,2,3] . Consequentely, with the idea to utilise the solar radiations for these photochemical reactions, these N-(α- cyano-α-substituted phenyl)- methylanilines (I) have been subjected to solar radiations, as these compounds (I) have been reported to undergo photodecomposition on exposure to sunlight. Earlier from these laboratories the synthesis of substituted benzoimidazoloquinolines[4] and a photoredox reaction of N-(α-cyano-α-substituted phenyl)- methylanilines under unsensitised condition and consuming longer time period with poor yields have been reported[5] .

EXPERIMENTAL
All the chemicals and solvents (Aldrich company U.S.A and B.D.H standard) used for this photoredox reaction were of high purity and were used without further purification. These reactions were monitored intermitantly by percolated alumina, silica gel 60 F 254 thin layer plates procured from Merck Company. All melting points were measured with an open capillary apparatus are uncorrected. All the compounds were characterized through their IR, 1H NMR, 13C NMR, mass spectral studies and elemental analysis. IR spectra were recorded on a Perkin Elmer RXIFT infrared spectrometer using KBr pellets. 1H NMR and 13C NMR spectra were recorded on a 400 MHz Bruker advance spectrometer using TMS as internal standard. Mass spectra was recorded on Thermo scientific LTQ-XLLCMS. Elemental analysis was carried out using Elementar Vario Micro cube CHN analyzer. General procedure for the synthesis of 3- hydroxy-9-methyl-2-oxo-1,2,2a,11-tetrahydrobenzo [3,4-a] imidazolo [3,4-a] quinoline (I) General procedure for the preparation of azomethines variously substituted azomethines were prepared by following identical procedure as described in literature[8] . Synthesis of 2-(3- methylbenzylideneamino) phenol is described as a representative case. 2-Hydroxybenzaldehyde 1.22 g (0.01 mol) were mixed with 1.07 g (0.01 mol) of m-toluidine in 10cc of ethyl alcohol. The reaction mixture after gentle warming provided the required azomethine. M.p. 79-810C. (II) General Procedure for the preparation of N-(α-cyano-α-substituted phenyl)- methylanilines To the aqueous methanolic solution of azomethine 2.11 g (0.01 mol) taken in conical flask, an equimolar quantity of sodium cyanide 1.06 g (0.01 mol) were added in good ventilated hood. The reaction mixture was kept for overnight period. Usual work up of reaction mixture provided the crystalline product which was recrystallized from petroleum ether. M.p. 98- 1000C. (III) General Procedure for the preparation of 2-oxo-1,2,2a,11-tetrahydro-benzo[3,4-a] imidazolo[3,4-a] quinoline An alcoholic solution of doubly recrystallized 3.2 g (0.01 mol) of N-(α-cyano-α-substituted phenyl)-methyl-3-toluidine in methanol (300 ml) was taken in a one litre capacity conical soda glass flask. To this mixture were added potassium hydroxide (2.0 g), potassium iodide (7.5 g) and few crystal of benzophenone. To ensure the expulsion of dissolved oxygen in the reaction mixture it was flushed with nitrogen gas for a period of half an hour to provide an inert atmosphere. Finally the flask stoppered tightly and exposed to sunlight for one week (40 hour approximately) turning the reaction mixture dark brown. After this period, excess of methanol was pulled off in vacuo. The mother liquor was extracted with solvent ether. The etheral layer was dried over anhydrous magnesium sulphate and on pulling off the ether in vacuo provided the crude product which on recrystallization from petroleum ether yielded cream coloured crystalline 3-hydroxy-9-methyl-2-oxo-1,2,2a,11- tetrahydro-benzo[3,4-a] imidazolo[3,4- a]quinoline in 78% yield m.pt 225-270C (Scheme 1). These benzoimidazoloquinolines have been characterized through elemental analysis, IR, 1H NMR, 13C NMR and high resolution mass spectral data[8] . General Procedure for the preparation of 2- oxo-1,2,2a,11-tetrahydro-benzo[3,4-a] imidazolo[3,4-a] quinoline All these benzoimidazoloquinolines (IIa to IIi) were prepared by following identical procedure (table 1 and table 2). 10-Methyl-2-oxo-1,2,2a,11-tetrahydrobenzo[3,4- a]imidazolo[3,4-a]quinoline (IIa) M.p.: 153- 550C; Yield 75%; IR (Potassium bromide): 3366- 3310 (-N-H), 1715 ( C N H O ), 1610-1585 (C=C) cm-1 ; 1H NMR (400 MHz, CDCl3) δ 2.3 (s, 3H, - CH3), 6.6 (m, 2H, -CH2), 5.3 (s, H, -CH), 7.0-8.1 (m, 7H, Ar), 1.5 (s, 1H, -NH); 13C NMR (400MHz, CDCl3) δ: 22.6, 116.3, 117.7, 118.7, 120.3, 121.5, 126.4, 127.7, 128.4, 131.5, 131.6, 132.5, 137.6, 141.7, 147.3, 156.4, 158.3; MS: Molecular ion peak m/z 250.22; Anal.Calcd for C16H14N2O: C, 76.77; H, 5.67; N, 11.23; Found: C, 76.27; H, 5.36; N, 11.10. 9-Methyl-2-oxo-1,2,2a,11-tetrahydro-benzo[3,4,- a]imidazolo[3,4-a]quinoline (IIb). M.p.: 232- 350C; Yield: 74%; IR (Potassium bromide): 3372-3329 (-N-H), 1711 ( C N H O ), 1603-1582 (C=C) cm-1 ; 1H NMR (400 MHz, CDCl3) δ 2.1 (s, 3H, -CH3), 6.8 (m, 2H, -CH2), 5.4 (s, H, -CH), 7.2-8.0 (m, 7H, Ar), 1.5 (s, 1H, -NH); 13C NMR (400MHz, CDCl3) δ: 23.5, 116.5,117.7, 118.5, 120.3, 120.8, 126.4, 127.8, 128.8, 131.3, 131.4, 132.4, 137.5, 141.8, 147.6, 155.4, 159.3; MS: Molecular ion peak m/z 250.43; Anal.Calcd for C16H14N2O: C, 76.78; H, 5.64; N, 11.19; Found: C, 76.23; H, 5.32; N, 11.03. 9-Chloro-2-oxo-1,2,2a,11-tetrahydro-benzo[3,4,- a]imidazolo[3,4-a]quinoline (IIc). M.p.: 128- 300C; Yield: 73%; IR (Potassium bromide): 3386-3317 (-N-H), 1720 ( C N H O ), 1610-1590

(C=C) cm-1 ; 1H NMR (400MHz, CDCl3) δ : 6.6 (m, 2H, -CH2), 5.5 (s, H, -CH), 6.8-7.9 (m, 7H, Ar), 1.3 (s, 1H, -NH); 13C NMR (400MHz, CDCl3) δ: 116.4, 117.3, 118.2 121.3, 121.4, 126.3, 127.4, 128.6, 131.5, 131.4, 132.2, 137.4, 140.8, 146.6, 156.4, 158.3; MS: Molecular ion peak m/z 270.87; Anal.Calcd for C15H11ClN2O: C, 66.55; H, 4.10; N, 10.35; Found: C, 66.03; H, 4.02; N, 10.11. 3-Hydroxy-10-methyl-1,2,2a,11-tetrahydrobenzo[3,4,-a]imidazolo[3,4-a]quinoline (IId). M.p.: 232-34oC; Yield: 76%; IR (Potassium bromide): 3373-3310 (-N-H), 1723 ( C N H O ), 1615-1566 (C=C) cm-1 ; 1H NMR (400 MHz, CDCl3) δ: 2.3 (s, 3H, -CH3), 6.7 (m, 2H, -CH2) , 5.1 (s, H, -CH), 7.2-8.0 (m, 6H, Ar), 8.2 (s, 1H, - OH), 1.2 (s, 1H, -NH); 13C NMR (400MHz, CDCl3) δ: 22.6, 116.3, 117.5, 119.2 120.3, 120.4, 126.6, 127.7, 128.4, 130.5, 130.2, 132.4, 137.2, 140.5, 146.4, 155.4, 159.3; MS: Molecular ion peak m/z 266.56; Anal. Calcd. for C16H14N2O2: C ,72.27; H, 5.28; N, 10.34; Found: C, 72.02; H, 5.09; N, 10.24. 3-Hydroxy-9-methyl-2-oxo-1,2,2a,11-tetrahydrobenzo[3,4.-a]imidazolo[3,4-a]quinoline(IIe). M.p.: 225-27oC; Yield: 78%; IR (Potassium bromide): 3376 (-N-H), 1725 ( C N H O ), 1615- 1566 (C=C) cm-1 ; 1H NMR (400 MHz, CDCl3) δ: 2.5 (s, 3H, -CH3), 6.9 (m, 2H, - CH2) , 5.3 (s, H, -CH), 7.1-8.2 (m, 6H, Ar), 8.3 (s, 1H, -OH), 0.6(s, 1H, -NH); 13C NMR (400MHz, CDCl3) δ: 21.4 ,112.7, 117.8, 118.6, 120.5, 120.7, 123.9, 127.5, 128.8, 131.2, 131.2, 132.7, 136.3, 140.7, 147.6, 155.7, 159.2; MS: Molecular ion peak m/z 266.23 and others prominent peak are at m/z 221.21, 206.25, 191.31, 163.31, 107.25, 77.25; Anal. Calcd. for C16H14N2O2: C ,72.16; H, 5.30; N, 10.50; Found: C, 72.07; H, 5.27; N, 10.32. 9-Chloro-3-hydroxy-2-oxo-1,2,2a,11-tetrahydrobenzo[3,4,-a]imidazolo[3,4-a]quinoline(IIf). M.p.: 200-02 0C; Yield: 72%; IR (Potassium bromide): 3373 (-N-H), 1725 ( C N H O ), 1590- 1575 (C=C) cm-1; 1H NMR (400 MHz, CDCl3) δ: 6.4 (m, 2H, -CH2), 5.6 (s, H, -CH-), 6.8-7.8 (m, 6H, Ar), 1.2 (s, 1H, -NH), 8.1 (s, 1H, OH); 13C NMR (400MHz, CDCl3) δ: 112.4, 117.4, 117.9, 121.2, 121.4, 123.5, 127.4, 128.3, 130.2, 130.6, 132.7, 136.3, 140.3, 147.4, 155.4, 158.2; MS: Molecular ion peak m/z 286; Anal.Calcd for C15H11ClN2O2: C, 62.84; H, 3.87; N, 9.77; Found: C, 62.14; H, 3.23; N,9.28. 5-Methoxy-10-methyl-2-oxo-1,2,2a,11- tetrahydro-benzo[3,4,-a]imidazolo[3,4- a]quinoline (IIg). M.p.: 137-390C; Yield: 71%; IR (Potassium bromide): 3365 (-N-H), 1725 ( C N H O ), 1600-1585 (C=C) cm-1 ; 1H NMR(400MHz, CDCl3) δ: 6.2 (m, 2H, -CH2), 5.6 (s, H, -CH), 6.8-7.9 (m, 6H, Ar), 1.2 (s, 1H, - NH), 2.7 (s, 3H, CH3), 3.4 (s, 3H, -OCH3); 13C NMR (400MHz, CDCl3) δ: 24.7, 114.4, 117.2, 117.5, 121.4, 121.6, 123.6, 127.3, 128.6, 130.4, 130.4, 132.3, 136.5, 140.6, 147.7, 154.6, 158.8; MS: Molecular ion peak m/z 280; Anal.Calcd for C17H16N2O2: C, 72.84; H, 5.75; N, 9.99; Found C, 72.15; H, 5.23; N, 9.16. 5-Methoxy-9-methyl-2-oxo-1,2,2a,11tetrahydrobenzo[3,4,-a]imidazolo[3,4-a]quinoline (IIh)., M.p.: 127-29 0C, Yield: 72%; IR (Potassium bromide): 3360 (-N-H), 1720 ( C N H O ), 1600- 1580 (C=C) cm-1 ; 1H NMR (400 MHz, CDCl3) δ: 6.3 (m, 2H, -CH2), 5.5 (s, 1H, -CH), 6.8-8.1 (m, 6H, Ar), 1.3 (s,1H, -NH), 2.5 (s, 3H, CH3), 3.2 (s, 3H, -OCH3); 13C NMR (400MHz, CDCl3) δ: 23.7, 112.4, 116.7, 117.4, 117.6, 120.4, 120.6, 126.6, 127.5, 128.4, 131.4, 131.3, 132.5, 136.7, 140.5, 147.5, 153.7, 158.4; MS: Molecular ion peak m/z 280; Anal.Calcd for C17H16N2O2: C, 72.84; H, 5.75; N, 9.99; Found: C, 72.12; H, 5.23; N, 9.14. 5-Methoxy-9-chloro-2-oxo-1,2,2a,11-tetrahydrobenzo[3,4,-a]imidazolo[3,4-a]quinoline(Ii).

M.p.: 122-25 0C; Yield: 73%; IR (Potassium bromide): 3360 (-N-H), 1720 ( C N H O ), 1610- 1585 (C=C) cm-1 ; 1H NMR (400MHz, CDCl3) δ: 6.3 (m, 2H, -CH2), 5.4 (s, H, -CH-), 6.8-7.9 (m, 6H, Ar), 1.3 (s, 1H, -NH), 3.2 (s, 1H, -OCH3); 13C NMR (400MHz, CDCl3) δ: 112.6, 117.7, 117.6, 117.5, 121.3, 121.5, 126.7, 127.4, 128.7, 130.5, 130.5, 132.5, 136.7, 140.7, 147.6, 153.7, 158.4; MS: Molecular ion peak m/z 300; Anal.Calcd for C16H13ClN2O2: C, 63.90; H, 4.36; N, 9.31; Found: C, 63.11; H, 4.04; N, 9.09.

RESULTS AND DISCUSSION
Present study describes the synthesis of variously substituted N-(α-cyano-α-substituted phenyl)- methylanilines which have been obtained by the hydrocyanic acid addition on substituted open chain azomethines and subsequently their photoredox reaction under sensitized conditions. To the methanolic solution of these N-(α-cyanoα-substituted phenyl)- methylanilines were added an aqueous solution of potassium hydroxide, potassium iodide and benzophenone and this reaction mixture was exposed to direct sunlight in soda glass reactor. Under the sensitized conditions, these N-(α- cyano-α-substituted phenyl)-methylanilines smoothly transformed to provide a new fused heterocyclic ring system (II) in lesser time as required under unsensitized conditions[6] (Scheme 1). These compounds have been characterized as substituted 2-oxo-1,2,2a,11-tetrahydrobenzo[3,4- a]imidazolo[3,4-a] quinoline derivatives through their elemental analysis, IR, proton magnetic resonance, 13C NMR and high resolution mass spectra. In infrared spectrum of 3-Hydroxy-9- methyl-2-oxo-1,2,2a,11-tetrahydrobenzo[3,4- a]imidazolo[3,4-a]quinoline shows medium intensity absorption bands in the region 3376- 3315 cm-1 which has been assigned to the secondary amide function (-N-H-stretching). The lower position of these bands indicates the presence of either inter or intramolecular hydrogen bonding in these products. Strong infrared absorption band at 1725 cm-1 has been assigned to the cyclic amido carbonyl function ( ). Absorption bands in the region 1654-1566 cm-1 has been assigned to the aromatic carbon-carbon double bond stretching vibrations. Weak intensity absorption bands in the region 1410-1400 cm-1 correspond to carbon-nitrogen single bond vibrations. The various infrared absorption bands indicate that transformation of nitrile function present in α-cyanoamines has occurred as absorption band corresponding to the nitrile function is missing.

In the high resolution (400 MHz) proton magnetic resonance spectrum of 3-Hydroxy-9- methyl-2-oxo-1,2,2a,11-tetrahydro-benzo[3,4-a] imidazolo [3,4-a] quinoline shows multiplet at δ 8.2-7.1 (equivalent to six protons) which has been assigned to aromatic protons, another multiplet at δ 6.9 (equivalent to two proton) which has been assigned to the methylenic protons (-CH2-), a broad singlet at δ 5.3 (equivalent to one proton) has been assigned to the methynic proton (-CH-), a singlet at δ 2.5 (equivalent to three protons) has been assigned to one methyl group and a broad absorption signal at δ 0.6 (equivalent to one proton) has been assigned an amido proton (-NH), on deuterium exchange the signal for this (- N-H-) proton disappears confirming the presence of one active proton on the amine function. In their 13C NMR spectra, compound 3-Hydroxy9-methyl-2-oxo-1,2,2a,11-tetrahydro-benzo[3,4- a]imidazolo [3,4-a]quinoline displays signal at δ 159.2 has been assigned to carbonyl carbon while another signal at δ 155.7 has been assigned to phenolic carbon. The aniline carbon displays its signal at δ 147.6 and the tolylic carbon displays its signal at δ 140.7. The other signals at δ 132.7, 120.7, 120.5, 128.8, 131.2, 131.2, 127.5, 136.3 corresponds to C-10, C-8, C-7, C-6b, C-5, C-4, C-6, C-2b. The signal at δ 119.5 has been assigned to carbon atom of benzylic group while a signal at δ 118.6 assigned to carbon atom of methylene group. The signal at δ 21.4 assigned to carbon atom of methyl group. In high resolution mass spectra of 3-Hydroxy-9- methyl-2-oxo-1,2,2a,11-tetrahydro-benzo [3,4-a] imidazolo[3,4-a]quinoline, the molecular ion peak appears at m/z 266. The base peak appears at m/z 193 due to the loss of a neutral molecule aziridinones molecule and phenolic group OH. The molecular ion peak loses hydrogen cyanide H-N-C=O to give a peak at m / z 221. The other ion peak appears at m / z 206 with the loss of methyl (-CH3) group. With the loss of O+ ion, the prominent ion peak appears at m / z 191. Then the loss of (-HCN) gives the daughter ion peak at m / z 166. Others ion peaks at m / z 106, 78 appear on fission of the fragment ions. Under these reaction conditions, benzophenone seems to transfer its energy to α-cyanoamine to form diradical specie on which hydroxide free radical generated in situ by iodide salt, to form hydroxyamino radical which is subsequently attacked by hydroxymethyl radical[7], during photoirradiation the hydroxymethylamino intermediate gets dehydrated to form imidazoline intermediate, bringing the two aromatic C-phenyl and N-phenyl rings in close proximity which on oxidation with loss of H-atom get connected to form fused cyclic imidazolo ring system (Scheme 2)

CONCLUSION
Moreover the originality of the work lies in using simple reagents which are easily available at convenience. The synthesis of improved yields of substituted benzoimidazoloquinolines with sensitized benzophenone which act as a catalyst in synthesis.

ACKNOWLEDGEMENT
The author wish to thank SAIF (PU) and NIPER (Mohali) for spectral studies.

References:

1. Kaneko, C.; Yokee, I.; Ishikawa, M. Tetrahedron . 1967, 5233.

2. Chow, Y. L.; Haque. Canad. J. Chem. 1968, 46, 290.

3. Omura, K.; Matsura, T. J.C.S Chem. Commun. 1966, 1615.

4. Singal, K. K.; Singh, B. Synthetic communication. 1985, 829.

5. Singal, K. K .; Singh, B. Chemica Acta Turcica. 1998, 26, 1.

6. Ohno, M.; Shibahara, S.; Kondo, S.; Maeda, K.; Umezawa. J. Amer. Chem. Soc. 1974, 96, 4326.

7. Pfoertner, K. H. Helv. Chim Acta. 1975, 58, 865. 8. Layer, R. W. Chem Rev. 1963, 63, 489.

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A Study by Rosa PS et al. entitled "Emotional State Due to the Covid – 19 Pandemic in People Residing in a Vulnerable Area in North Lima" is awarded Best Article for Vol 13 issue 14

A Study by Suvarna Sunder J et al. entitled "Endodontic Revascularization of Necrotic Permanent Anterior Tooth with Platelet Rich Fibrin, Platelet Rich Plasma, and Blood Clot - A Comparative Study" is awarded Best Article for Vol 13 issue 13

A Study by Mona Isam Eldin Osman et al. entitled "Psychological Impact and Risk Factors of Sexual Abuse on Sudanese Children in Khartoum State" is awarded Best Article for Vol 13 issue 12

A Study by Khaw Ming Sheng & Sathiapriya Ramiah entitled "Web Based Suicide Prevention Application for Patients Suffering from Depression" is awarded Best Article for Vol 13 issue 11

A Study by Purushottam S. G. et al. entitled "Development of Fenofibrate Solid Dispersions for the Plausible Aqueous Solubility Augmentation of this BCS Class-II Drug" is awarded Best article for Vol 13 issue 10

A Study by Kumar S. et al. entitled "A Study on Clinical Spectrum, Laboratory Profile, Complications and Outcome of Pediatric Scrub Typhus Patients Admitted to an Intensive Care Unit from a Tertiary Care Hospital from Eastern India" is awarded Best Article for Vol 13 issue 09

A Study by Mardhiah Kamaruddin et al. entitled "The Pattern of Creatinine Clearance in Gestational and Chronic Hypertension Women from the Third Trimester to 12 Weeks Postpartum" is awarded Best Article for Vol 13 issue 08

A Study by Sarmila G. B. et al. entitled "Study to Compare the Efficacy of Orally Administered Melatonin and Clonidine for Attenuation of Hemodynamic Response During Laryngoscopy and Endotracheal Intubation in Gastrointestinal Surgeries" is awarded Best Article for Vol 13 issue 07

A Study by M. Muthu Uma Maheswari et al. entitled "A Study on C-reactive Protein and Liver Function Tests in Laboratory RT-PCR Positive Covid-19 Patients in a Tertiary Care Centre – A Retrospective Study" is awarded Best Article of Vol 13 issue 06 Special issue Modern approaches for diagnosis of COVID-19 and current status of awareness

A Study by Gainneos PD et al. entitled "A Comparative Evaluation of the Levels of Salivary IgA in HIV Affected Children and the Children of the General Population within the Age Group of 9 – 12 Years – A Cross-Sectional Study" is awarded Best Article of Vol 13 issue 05 Special issue on Recent Advances in Dentistry for better Oral Health

A Study by Alkhansa Mahmoud et al. entitled "mRNA Expression of Somatostatin Receptors (1-5) in MCF7 and MDA-MB231 Breast Cancer Cells" is awarded Best Article of Vol 13 issue 06

A Study by Chen YY and Ghazali SRB entitled "Lifetime Trauma, posttraumatic stress disorder Symptoms and Early Adolescence Risk Factors for Poor Physical Health Outcome Among Malaysian Adolescents" is awarded Best Article of Vol 13 issue 04 Special issue on Current Updates in Plant Biology to Medicine to Healthcare Awareness in Malaysia

A Study by Kumari PM et al. entitled "Study to Evaluate the Adverse Drug Reactions in a Tertiary Care Teaching Hospital in Tamilnadu - A Cross-Sectional Study" is awarded Best Article for Vol 13 issue 05

A Study by Anu et al. entitled "Effectiveness of Cytological Scoring Systems for Evaluation of Breast Lesion Cytology with its Histopathological Correlation" is awarded Best Article of Vol 13 issue 04

A Study by Sharipov R. Kh. et al. entitled "Interaction of Correction of Lipid Peroxidation Disorders with Oxibral" is awarded Best Article of Vol 13 issue 03

A Study by Tarek Elwakil et al. entitled "Led Light Photobiomodulation Effect on Wound Healing Combined with Phenytoin in Mice Model" is awarded Best Article of Vol 13 issue 02

A Study by Mohita Ray et al. entitled "Accuracy of Intra-Operative Frozen Section Consultation of Gastrointestinal Biopsy Samples in Correlation with the Final Histopathological Diagnosis" is awarded Best Article for Vol 13 issue 01

A Study by Badritdinova MN et al. entitled "Peculiarities of a Pain in Patients with Ischemic Heart Disease in the Presence of Individual Combines of the Metabolic Syndrome" is awarded Best Article for Vol 12 issue 24

A Study by Sindhu Priya E S et al. entitled "Neuroprotective activity of Pyrazolone Derivatives Against Paraquat-induced Oxidative Stress and Locomotor Impairment in Drosophila melanogaster" is awarded Best Article for Vol 12 issue 23

A Study by Habiba Suhail et al. entitled "Effect of Majoon Murmakki in Dysmenorrhoea (Usre Tams): A Standard Controlled Clinical Study" is awarded Best Article for Vol 12 issue 22

A Study by Ghaffar UB et al. entitled "Correlation between Height and Foot Length in Saudi Population in Majmaah, Saudi Arabia" is awarded Best Article for Vol 12 issue 21

A Study by Siti Sarah Binti Maidin entitled "Sleep Well: Mobile Application to Address Sleeping Problems" is awarded Best Article for Vol 12 issue 20

A Study by Avijit Singh"Comparison of Post Operative Clinical Outcomes Between “Made in India” TTK Chitra Mechanical Heart Valve Versus St Jude Mechanical Heart Valve in Valve Replacement Surgery" is awarded Best Article for Vol 12 issue 19

A Study by Sonali Banerjee and Mary Mathews N. entitled "Exploring Quality of Life and Perceived Experiences Among Couples Undergoing Fertility Treatment in Western India: A Mixed Methodology" is awarded Best Article for Vol 12 issue 18

A Study by Jabbar Desai et al. entitled "Prevalence of Obstructive Airway Disease in Patients with Ischemic Heart Disease and Hypertension" is awarded Best Article for Vol 12 issue 17

A Study by Juna Byun et al. entitled "Study on Difference in Coronavirus-19 Related Anxiety between Face-to-face and Non-face-to-face Classes among University Students in South Korea" is awarded Best Article for Vol 12 issue 16

A Study by Sudha Ramachandra & Vinay Chavan entitled "Enhanced-Hybrid-Age Layered Population Structure (E-Hybrid-ALPS): A Genetic Algorithm with Adaptive Crossover for Molecular Docking Studies of Drug Discovery Process" is awarded Best article for Vol 12 issue 15

A Study by Varsha M. Shindhe et al. entitled "A Study on Effect of Smokeless Tobacco on Pulmonary Function Tests in Class IV Workers of USM-KLE (Universiti Sains Malaysia-Karnataka Lingayat Education Society) International Medical Programme, Belagavi" is awarded Best article of Vol 12 issue 14, July 2020

A study by Amruta Choudhary et al. entitled "Family Planning Knowledge, Attitude and Practice Among Women of Reproductive Age from Rural Area of Central India" is awarded Best Article for special issue "Modern Therapeutics Applications"

A study by Raunak Das entitled "Study of Cardiovascular Dysfunctions in Interstitial Lung Diseas epatients by Correlating the Levels of Serum NT PRO BNP and Microalbuminuria (Biomarkers of Cardiovascular Dysfunction) with Echocardiographic, Bronchoscopic and HighResolution Computed Tomography Findings of These ILD Patients" is awarded Best Article of Vol 12 issue 13

A Study by Kannamani Ramasamy et al. entitled "COVID-19 Situation at Chennai City – Forecasting for the Better Pandemic Management" is awarded best article for Vol 12 issue 12

A Study by Muhammet Lutfi SELCUK and Fatma entitled "Distinction of Gray and White Matter for Some Histological Staining Methods in New Zealand Rabbit's Brain" is awarded best article for Vol 12 issue 11

A Study by Anamul Haq et al. entitled "Etiology of Abnormal Uterine Bleeding in Adolescents – Emphasis Upon Polycystic Ovarian Syndrome" is awarded best article for Vol 12 issue 10

A Study by entitled "Estimation of Reference Interval of Serum Progesterone During Three Trimesters of Normal Pregnancy in a Tertiary Care Hospital of Kolkata" is awarded best article for Vol 12 issue 09

A Study by Ilona Gracie De Souza & Pavan Kumar G. entitled "Effect of Releasing Myofascial Chain in Patients with Patellofemoral Pain Syndrome - A Randomized Clinical Trial" is awarded best article for Vol 12 issue 08

A Study by Virendra Atam et. al. entitled "Clinical Profile and Short - Term Mortality Predictors in Acute Stroke with Emphasis on Stress Hyperglycemia and THRIVE Score : An Observational Study" is awarded best article for Vol 12 issue 07

A Study by K. Krupashree et. al. entitled "Protective Effects of Picrorhizakurroa Against Fumonisin B1 Induced Hepatotoxicity in Mice" is awarded best article for issue Vol 10 issue 20

A study by Mithun K.P. et al "Larvicidal Activity of Crude Solanum Nigrum Leaf and Berries Extract Against Dengue Vector-Aedesaegypti" is awarded Best Article for Vol 10 issue 14 of IJCRR

A study by Asha Menon "Women in Child Care and Early Education: Truly Nontraditional Work" is awarded Best Article for Vol 10 issue 13

A study by Deep J. M. "Prevalence of Molar-Incisor Hypomineralization in 7-13 Years Old Children of Biratnagar, Nepal: A Cross Sectional Study" is awarded Best Article for Vol 10 issue 11 of IJCRR

A review by Chitra et al to analyse relation between Obesity and Type 2 diabetes is awarded 'Best Article' for Vol 10 issue 10 by IJCRR.

A study by Karanpreet et al "Pregnancy Induced Hypertension: A Study on Its Multisystem Involvement" is given Best Paper Award for Vol 10 issue 09

List of Awardees

A Study by Ese Anibor et al. "Evaluation of Temporomandibular Joint Disorders Among Delta State University Students in Abraka, Nigeria" from Vol 13 issue 16 received Emerging Researcher Award

A Study by Alkhansa Mahmoud et al. entitled "mRNA Expression of Somatostatin Receptors (1-5) in MCF7 and MDA-MB231 Breast Cancer Cells" from Vol 13 issue 06 received Emerging Researcher Award

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