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Chaudhary R.G.,Seth Kesarimal Porwal College | Juneja H.D.,Rashtrasant Tukadoji Maharaj Nagpur University | Gharpure M.P.,Rashtrasant Tukadoji Maharaj Nagpur University | Meshra V.P.,Dharmpeth Science College
Research Journal of Pharmaceutical, Biological and Chemical Sciences | Year: 2012

This article deals with preparative and structural studies of some transition metal polymeric complexes. The metal polymeric complexes were synthesized from bis-ligand with metal salt in dimethylformamide medium by condensation method and their structures have been evaluated by spectral, magnetic moment measurements, X-ray diffraction, thermogravimetric analysis XRD analysis reveals amorphous natures of metal polymeric complexes. Furthermore, scanning electron microscope studies have been performed to determine the shape and size of metal polymeric complexes. The solid reflectance and magnetic moment studies supported significantly tetrahedral geometry for Zn(II), Cd(II) and Hg(II) polymeric complexes. The lattice water was identified by IR, CHN and thermal analysis. Source


Chaudhary R.G.,Seth Kesarimal Porwal College | Chaudhary R.G.,Rashtrasant Tukadoji Maharaj Nagpur University | Juneja H.D.,Rashtrasant Tukadoji Maharaj Nagpur University | Pagadala R.,University of KwaZulu - Natal | And 2 more authors.
Journal of Saudi Chemical Society | Year: 2014

The four chelate polymer complexes commonly called as coordination polymers of Mn(II), Co(II), Ni(II) and Cu(II) ions with fbpmpc (fbpmpc = fumaroyl bis (paramethoxyphenylcarbamide)) were synthesized and characterised by elemental analyses, infrared spectroscopy, diffuse reflectance, magnetic moment susceptibility, thermal analysis, X-ray diffraction, electrical conductivity and scanning electron microscopy technique (SEM). SEM investigations of coordination polymers were found in different shapes and sizes, though they are synthesized from a single ligand. Each metal ion is coordinated by a bis (bidentate) manner through oxygen atom of the carboxylato group and the nitrogen atom of an amide group of ligand and two aqua ligands by coordinated bond which formed 6-member heterocyclic ring. In the present article, the main aim of research study is to find out the comparative studies of coordination polymers such as thermogravimetry (TG), derivative thermogravimetry (DTG), differential thermal analysis (DTA), electrical conductivity and morphology behaviour. Furthermore, the electrical conductivities of chelating ligand and coordination polymers were determined in the solid state powder form. The electrical conductivities measurements of undoped and doped ligand, coordination polymers were carried out at room temperature by the four probe technique using an electrometer. Thermal degradation studies of the coordination polymers have been carried out from a non-isothermal condition under nitrogen atmosphere at a heating rate of 10 °C min-1. The decomposition steps and thermal stabilities of these complexes were confirmed by thermal analysis techniques (TG/DTG/DTA). The thermal studies inferred the presence of crystallized water in all coordination polymers, whereas coordinated water was found in Ni(II) and Cu(II) ions. © 2014. Source


Lal K.,Rashtrasant Tukadoji Maharaj Nagpur University | Paliwal L.J.,Rashtrasant Tukadoji Maharaj Nagpur University | Bagade M.B.,Seth Kesarimal Porwal College
Letters in Organic Chemistry | Year: 2016

An environmentally benign protocol for the synthesis of some new 3, 4-dihydropyrimidin- 2-(1H)-ones and thiones promoted by p-Toulene Sulfonic Acid (PTSA) efficiently catalyzes the three component condensation reaction of formylchromone, substituted acetophenones and urea/thiourea under microwave irradiation (MWI). Compared to the classical Biginelli reaction conditions, this new methodology consistently has the advantage of giving good yields, require less reaction time, mild conditions with simple workup procedure. Newly synthesized compounds show moderate to good antimicrobial properties against some gram positive and gram negative bacteria. Background: During recent years, dihydropyrimidinones have emerged as a vital compound with diverse biological and pharmacological applications. P. Biginelli in 1893 was the first chemist to report the three component condensation, using ethylacetoacetate with different aldehydes and urea for the synthesis of dihydropyrimidine under acidic condition. However, serious drawback of this reaction has been the low yields obtained in the case of substituted aromatic and aliphatic aldehydes. Several improved procedures for the synthesis of dihydropyrimidines have been recently reported to enhance the efficiency of the Biginelli reaction, using various catalysts. Inspite of their potential utility many of the existing methods suffer from some drawbacks, such as the use of strong acidic conditions, long reaction times, tedious workup procedures, posing environmental hazards, and low yield of the products. The present work describes a novel approach toward the solvent-free one-pot synthesis of some novel dihydropyrimidine derivatives using formylchromone, substituted acetophenones and urea/thiourea under Microwave Irradiation (MWI) as well as by conventional method using p- Toulene,sulfonic acid (PTSA) as catalyst. Objective: To develop an environment friendly method to get high yield and purity for the one-pot synthesis of some novel 3,4-Dihydropyrimidine derivatives. Also, incorporation of various functional groups along with other heterocyclic ring like chromone nucleus has been introduced to increase the efficacy of antimicrobial properties. Methods: Conventional Method: A mixture of 2.24g (0.01mol) 4-Oxo-4-H-benzo[h]chromene-3-carbaldehyde (1) was refluxed for 12-14 h with substituted Acetophenones (0.01mol) (2a: 1.2 mL), m-Nitroacetophenone (2b:1.65 g), p-Chloro acetophenone(2c:1.54 g), p-Hydroxy acetophenone, (2d:1.36 g), p-Bromo acetophenone (2e:1.99 g) and p- Nitroacetophenone(2f:1.65 g) and (0.01mol) of urea(0.60 g)/ thiourea(0.76 g) (3) in presence of p-toulene sulphonic acid (PTSA) (7-10 mol %, 13.3-19 g) as catalyst in 1,4 dioxane (30 mL). After the completion of reaction, the reaction mixture was poured into the cold water, filtered, washed with water, dried and was recrystallized using ethanol: Acetic acid (2:1). Microwave Irradiation Method: A mixture of 0.22 g (1 mmol) 4-Oxo-4-H-benzo[h]chromene-3-carbaldehyde (1), substituted acetophenones(1 mmol) (2a:0.12 mL), m-Nitro acetophenone(2b:0.165 g), p-Chloro acetophenone(2c:0.154 g), p- Hydroxy acetophenone(2d:0.136 g), p-Bromo acetophenone(2e:0.199 g) and p- Nitro acetophenone(2f:0.165 g) and (1 mmol) of urea (0.06 g)/ thiourea (0.076 g) (3) in presence of p-toulene sulphonic acid (PTSA) (1-3 mol %, 1.9-6.7 g) was irradiated at 300 W, 120°C for 15-20 min to get 4-(4-Oxo-4H-benzo[h]chromen-3-yl)-6-substituted phenyl-3,4- dihydropyrimidin-2(1H)-one. After the completion of reaction, the reaction mixture was poured into the cold water, filtered, washed with water, dried and was recrystallized using ethanol: Acetic acid (2:1). Results: 4-(4-Oxo-4H-benzo[h]chromen-3-yl)-6-substituted phenyl-3,4-dihydropyrimidin-2(1H)-one: 4(a-f) and 3-(6- Substituted phenyl-2-thioxo-1,2,3,4-tetrahydropyrimidin-4yl)-4H-benzo[h]chromen-4-one 5(a-f) were obtained by one-pot three component condensation of 4-Oxo-4-H-benzo[h]chromene-3-carbaldehyde(1), substituted acetophenones 2(a-f) and Urea / Thiourea (3) in presence of p-toulene sulphonic acid (PTSA) as a catalyst under microwave irradiation in solventfree condition. The present method has given excellent yields as compared to conventional method (Table 1). The schematic representation has been shown in Scheme 1. Under these conditions, the time for completion of reaction has been reduced dramatically and completed within 15-20 min as compared with the conventional method consuming 12-14 h to get the desired product. Different substituted acetophenones have been employed in this reaction successfully which showed large scope of this reaction for the synthesis of dihydropyrimidine derivatives. The newly dihydropyrimidines were synthesized by corresponding acetophenones, 4-Oxo-4-H-benzo[h]chromene-3-carbaldehyde and urea/thiourea in1,4-dioxane using conventional method as well as by green approach under microwave irradiation in solvent free conditions (Scheme 1). The percentage yield has been found to be drastically increased in case of solvent free condition under microwave irradiation. Synthesized compounds have been characterized on the basis of various spectroscopic techniques such as FTIR, HRMS, 1H and 13C NMR. HRMS of the compounds 4c and 5c showed two peaks of M+ Na in a ratio of 3:1 and confirmed the existence of chloro group. Similarly compounds, 4e and 5e showed two peaks of M+ Na peak in a ratio of 100:97.3 nearly 1:1 ratios which confirmed the existence of bromo group. 1H and 13C NMR also gave various corresponding peaks confirming the formation of various DHPMs. To investigate and evaluate the catalytic efficacy of different Lewis acids in this reaction, some other combinations have also been tried (Table 2). It is clear from these data (Table 2) the catalyst PTSA used in this reaction has been found to be most effective in synthesis of dihydropyrimidines with a better yield of the products in a very short reaction time. Other catalysts such as AlCl3.6H2O and ZnCl2 did not give the desired product. This protocol is practically general and several functionalities like nitro, chloro, hydroxyl and bromo were not affected during the course of reaction and were of special interest in the synthesis of dihydropyrimidines in a single step with high yield. An amount of (1-3 mol %) PTSA was found to be very effective under MWI and the use of less than that was not optimal. All the synthesized dihydropyrimidine derivatives 4(a-f) and 5(a-f) were tested for their in vitro antibacterial study against different strains of bacterial species such as S.aureus, B.subtillis, E.coli and K.aerogenes using well diffusion method. Antibacterial results have been summarized in (Table 3), which indicated that the most of the synthesized compounds exhibited moderate to good antibacterial properties against all bacterial strains and compared with standard drug Amoxicillin. Compounds 4b, 4c, 4d, 4e and 5f have exhibited excellent activity against E.coli species. Similarly compounds, 5b and 5f have showed excellent activity against S.aureus and compound 4e showed good activity against B.subtilis. All these compounds showed their activity at the concentration of 100μl. Remaining compounds exhibited moderate antibacterial activity as compared to the standard drug (Amoxicillin). Conclusion: In the course of our study an environment friendly, solvent-free, mild and efficient protocol for the synthesis of some new dihydropyrimidinones and thiones catalyzed by PTSA in MWI have been found to be of several advantages. It may be of high interest for a synthetic chemist for its simple and environmentally safe procedure. It has an easy workup with mild conditions, solvent-free, short reaction times (15-20 min) and produced excellent yields (80-95%). Furthermore, this series may provide new classes of biologically active compounds. The newly synthesized DHPM's showed moderate to good antimicrobial properties. Therefore, we expect our protocol will find its way to endow the requirements of pharmaceutical industries and institutions towards the invention of broad range of dihydropyrimidones and open a new pathway in the field of green chemistry which is the need of hour. © 2016 Bentham Science Publishers. Source


Kurian T.O.,Research Center for Chemistry | Sadaphale P.,Rashtrasant Tukadoji Maharaj Nagpur University | Paliwal L.J.,Rashtrasant Tukadoji Maharaj Nagpur University | Pandey P.K.,Rashtrasant Tukadoji Maharaj Nagpur University | And 2 more authors.
Journal of Chemical Crystallography | Year: 2013

The title compound 4-{(1E)-1-[(2E)-{[4-(dimethylamino)phenyl]methylidene} hydrazono]ethyl}benzene-1,3-diol (1) which is an azine moiety, has been synthesized by microwave irradiation technique. The characterization by IR and mass spectroscopy confirms the structure of (1). The crystal system, lattice parameters and molecular structure of (1) has been determined by single crystal X-ray diffraction technique. The crystallographic data for the compound (1) is being reported for the first time. Studies reveal that the compound exhibits intermolecular and intramolecular hydrogen bonding interactions in its crystal structure. The compound crystallizes in the monoclinic space group P21/n with unit cell dimensions a = 11.8734(7) Å; b = 9.6194(6) Å; c = 27.2410(16) Å; β = 96.435(3) Å; V = 3091.7(3) Å3 and D calc = 1.278 Mg/m3 for Z = 8. The surface morphology of the crystalline compound has been studied by SEM analysis. SEM reveals the microcrystalline features of the compound under study. © 2013 Springer Science+Business Media New York. Source

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