scholarly journals Natural dolomitic limestone catalyzed synthesis of benzimidazoles, dihydropyrimidinones and highly substituted pyridines under ultrasound irradiation

2020 ◽  
Author(s):  
Kumar Godugu ◽  
Venkata Divya Sri Yadala ◽  
Mohammad Khaja Mohinuddin Pinjari ◽  
Thrivikram Reddy Gundala ◽  
Lakshmi Reddy Sanapareddy ◽  
...  
Keyword(s):  
Ultrasound Irradiation ◽  
Significant Loss ◽  
Catalyst Loading ◽  
Dolomitic Limestone ◽  
X Ray Diffraction ◽  
Rapid Construction ◽  
Substituted Pyridines ◽  
Ft Ir ◽  
Low Catalyst Loading ◽  
First Time

In this paper, for the first time, naturally occurring dolomitic limestone is employed as a heterogeneous green catalyst for the synthesis of medicinally valuable N-heterocycles, 2-aryl-1-arylmethyl-1H-benzo[d]imidazoles, dihydropyrimidinones/ thiones and 2-amino-4-aryl-3,5-dicarbonitrile-6-sulfanyl-pyridines in good to excellent isolated yields via a rapid construction of C-N, C-C and C-S bond formations in 1:1 ratio of ethanol:H2O under ultrasound irradiation. Dolomitic limestone is characterized by X-ray diffraction (XRD), FT-IR, Raman and SEM with EDAX analyses. Further, the catalyst is environmentally benevolent, non-toxic, most abundant, easy to handle low catalyst loading and is reused 7 times without significant loss of catalytic activity. Hence, the catalyst is greener alternative for the synthesis of aforementioned N-heterocycles as compared with the existing reported catalysts.

scholarly journals Synthesis of pyrimidines by Fe3O4@SiO2-L-proline nanoparticles

2020 ◽  
Vol 43 (1) ◽  
pp. 117-124
Author(s):  
Javad Safaei-Ghomi ◽  
Zahra Samadi
Keyword(s):  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Catalyst Loading ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
High Yields ◽  
Low Catalyst Loading ◽  
Ft Ir Spectroscopy

AbstractFe3O4@SiO2-L-proline nanoparticles have been used as an effective catalyst for the preparation of pyrimidines by three-component reactions of 1,3-dimethylbarbituric acid, aromatic aldehydes and 4-methyl aniline or 4-methoxy aniline under reflux condition in ethanol. Fe3O4@SiO2-L-proline nanoparticles have been characterized by scanning electronic microscopy (SEM), powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), thermal gravimetric analysis (TGA), energy dispersive X-ray (EDS), dynamic light scattering (DLS) and FT-IR spectroscopy. This method provides several advantages including, the reusability of the catalyst, low catalyst loading, atom economy, short reaction times and high yields of products.

Synthesis and Characterization of Nanosized Manganese Oxyhydroxide Compounds by Sonochemical Method

2016 ◽  
Vol 35 (5) ◽  
pp. 493-498
Author(s):  
Masoud Salavati-Niasari ◽  
Mahdiyeh Esmaeili-Zare ◽  
Mina Gholami-Daghian ◽  
Samira Bagheri
Keyword(s):  
Electron Microscopy ◽  
Ultrasound Irradiation ◽  
Sonochemical Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Ft Ir ◽  
Manganese Oxyhydroxide ◽  
Average Size ◽  
First Time

AbstractManganese oxyhydroxide (MnOOH) nanoparticles were synthesized by the reaction of [Mn(Hsal)2] complex and NaOH in the presence of ultrasound irradiation. In this study, the effect of different reaction parameters such as type of solvent, sonication time and type of surfactant on the morphology and the particle size of product were studied. The as-synthesized nanoparticles, with an average size of 10–15 nm, were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and energy dispersive spectrometry (EDS). To the best of author’s knowledge, it is the first time that [Mn(Hsal)2] complex is used as manganese source for the synthesis of MnOOH nanoparticles.

scholarly journals Synthesis of Benzenesulfonamide Derivatives Via Ring Opening of Aziridines In The Presence of Magnetically Retrievable Graphene Based (CoFe@rGO) Nanohybrid.

2021 ◽  
Author(s):  
Ankush Sheoran ◽  
Komal ◽  
Jaspreet Kaur ◽  
Paramdeep Kaur ◽  
Jyoti Agarwal ◽  
...  
Keyword(s):  
Significant Loss ◽  
Solvent Free ◽  
Environmentally Benign ◽  
Nucleophilic Attack ◽  
Catalyst Loading ◽  
Aziridine Ring ◽  
Solvent Free Conditions ◽  
Aryl Amines ◽  
Ft Ir ◽  
Low Catalyst Loading

Abstract Graphene based magnetic nanohybrids have engrossed considerable research curiosity because of their exceptional properties and diverse applications associated with green chemistry. In this regard, a practical, facile and regioselective preparation of 1,2-diamines from N-tosylaziridine/(S)-(+)-2-Benzyl-1-(p-tolylsulfonyl)aziridine and aryl amines in the presence of magnetically separable graphene based nanohybrid (CoFe@rGO) has been proposed under mild and solvent free conditions. The FT-IR, FE-SEM, XRD and EDX spectroscopic analysis confirmed the formation of the CoFe@rGO nanohybrids. For unsymmetrical aziridine, nucleophilic attack of aryl amines was observed to take place selectively at the more substituted carbon atom of aziridine ring. Environmentally benign, efficient, shorter reaction time, solvent-free conditions, low catalyst loading, excellent reaction yields and reusability of the catalyst for six consecutive runs without significant loss in its activity are the key advantages of this protocol.

Characterization of SrBi2Nb2O9 Thin Films Prepared by Sol Gel Technique

1996 ◽  
Vol 459 ◽  
Author(s):  
E. Ching-Prado ◽  
W. Pérez ◽  
A. Reynés-Figueroa ◽  
R. S. Katiyar ◽  
D. Ravichandran ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Band ◽  
Sol Gel ◽  
Orthorhombic Symmetry ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Gel Technique ◽  
High Degree ◽  
First Time

ABSTRACTThin films of SrBi2Nb2O9 (SBN) with thicknesses of 0.1, 0.2, and 0.4 μ were grown by Sol-gel technique on silicon, and annealed at 650°C. The SBN films were investigated by Raman scatering for the first time. Raman spectra in some of the samples present bands around 60, 167, 196, 222, 302, 451, 560, 771, 837, and 863 cm−1, which correspond to the SBN formation. The study indicates that the films are inhomogeneous, and only in samples with thicknesses 0.4 μ the SBN material was found in some places. The prominent Raman band around 870 cm−1, which is the A1g mode of the orthorhombic symmetry, is assigned to the symmetric stretching of the NbO6 octahedrals. The frequency of this band is found to shift in different places in the same sample, as well as from sample to sample. The frequency shifts and the width of the Raman bands are discussed in term of ions in non-equilibrium positions. FT-IR spectra reveal a sharp peak at 1260 cm−1, and two broad bands around 995 and 772 cm−1. The bandwidths of the latter two bands are believed to be associated with the presence of a high degree of defects in the films. The experimental results of the SBN films are compared with those obtained in SBT (T=Ta) films. X-ray diffraction and SEM techniques are also used for the structural characterization.

scholarly journals Synthesis of new bimetallic phosphate (Al/Ag3PO4) and study for its Catalytic performance in the synthesis of 1,2-dihydro-l-phenyl-3H-naphth [1,2-e]-[1,3] oxazin-3-one derivatives

2021 ◽  
Vol 11 (3) ◽  
pp. 215
Author(s):  
Achraf El Hallaoui ◽  
Tourya Ghailane ◽  
Soukaina Chehab ◽  
Youssef Merroun ◽  
Rachida Ghailane ◽  
...  
Keyword(s):  
Reaction Times ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Silver Sulfate ◽  
Triple Super Phosphate ◽  
Aryl Aldehyde ◽  
Ft Ir ◽  
First Time

<p>This work aims to prepare a new bimetallic phosphate catalyst using a new simple and effective method. This new catalyst was ready for the first time by a modification of Triple Super Phosphate (TSP) fertilizer with silver sulfate (AgSO<sub>4</sub>), followed by the impregnation of the aluminum atoms using aluminum nitrate (Al(NO<sub>3</sub>)<sub>3</sub>). The use of Al/Ag<sub>3</sub>PO<sub>4</sub>, for the first time as a heterogeneous catalyst in organic chemistry, offers a new, efficient, and green pathway for synthesizing 1,2-dihydro-l-phenyl-3H-naphth[1,2-e]-[1,3]oxazin-3-one derivatives by one-pot three-component cyclocondensation of b-naphthol, aryl aldehyde, and urea. The structure and the morphology of the prepared catalyst were characterized by spectroscopic methods such as X-Ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), and dispersive X-ray spectrometry coupled with a scanning electron microscope (EDX-SEM). In addition, the optimization of the reaction parameters was carried out considering the effect of catalyst amount, the temperature, and the solvent. The procedure described herein allowed a comfortable preparation of oxazine derivatives with excellent yields, short reaction times, and in the absence of organic solvent.</p>

scholarly journals Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

2020 ◽  
Vol 16 ◽  
pp. 1881-1900
Author(s):  
Kumar Godugu ◽  
Venkata Divya Sri Yadala ◽  
Mohammad Khaja Mohinuddin Pinjari ◽  
Trivikram Reddy Gundala ◽  
Lakshmi Reddy Sanapareddy ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Dolomitic Limestone ◽  
Chromatographic Purification ◽  
Green Catalyst ◽  
Edax Analysis ◽  
Substituted Pyridines ◽  
Reaction Profile

Natural dolomitic limestone (NDL) is employed as a heterogeneous green catalyst for the synthesis of medicinally valuable benzimidazoles, dihydropyrimidinones, and highly functionalized pyridines via C–N, C–C, and C–S bond formations in a mixture of ethanol and H2O under ultrasound irradiation. The catalyst is characterized by XRD, FTIR, Raman spectroscopy, SEM, and EDAX analysis. The main advantages of this methodology include the wide substrate scope, cleaner reaction profile, short reaction times, and excellent isolated yields. The products do not require chromatographic purification, and the catalyst can be reused seven times. Therefore, the catalyst is a greener alternative for the synthesis of the above N-heterocycles compared to the existing reported catalysts.

Influence of Li2+ Doping on the Structural and Optical Properties of CaO Synthesized by Sol–Gel Process

2019 ◽  
Vol 07 (01n02) ◽  
pp. 1950002
Author(s):  
Nadir Lalou ◽  
Ahmed Kadari
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Lithium Nitrate ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Sol Gel Process ◽  
Ft Ir ◽  
First Time

This work proposes the synthesis of nanocrystalline calcium oxide (CaO) pure and doped with different concentrations of lithium (Li[Formula: see text]) ions by sol–gel process. Calcium nitrate (Ca(NO[Formula: see text]4H2O; 99.99%) and lithium nitrate (LiNO3; 99.99%) were used as precursors. The synthesized powders were characterized by several techniques such as: UV-Vis transmission spectroscopy, Fourier Transform Infra-red spectroscopy (FT-IR) and X-ray diffraction (XRD). The main objective of this paper is to study the influence of lithium (Li[Formula: see text] ratio) on the structural and optical properties of synthesized powders. The band gap values decreased with the increasing of Li[Formula: see text] ions in CaO lattice; the slight change in the band gap was directly related to the energy transfer between the CaO excited states and the 2s levels of Li[Formula: see text] ions. The influence of Li[Formula: see text] doping on the physical properties of CaO nanocrystalline will be studied for the first time in this work; no literature has previously published this kind of impurities.

scholarly journals Ru@hyperbranched Polymer for Hydrogenation of Levulinic Acid to Gamma-Valerolactone: The Role of the Catalyst Support

2022 ◽  
Vol 23 (2) ◽  
pp. 799
Author(s):  
Svetlana A. Sorokina ◽  
Stepan P. Mikhailov ◽  
Nina V. Kuchkina ◽  
Alexey V. Bykov ◽  
Alexander L. Vasiliev ◽  
...  
Keyword(s):  
Levulinic Acid ◽  
Catalyst Support ◽  
Physicochemical Characterization ◽  
Significant Loss ◽  
Catalyst Loading ◽  
Structure Property ◽  
Structure Property Relationships ◽  
Low Catalyst Loading

Hydrogenation of levulinic acid (LA) obtained from cellulose biomass is a promising path for production of γ-valerolactone (GVL)—a component of biofuel. In this work, we developed Ru nanoparticle containing nanocomposites based on hyperbranched pyridylphenylene polymer, serving as multiligand and stabilizing matrix. The functionalization of the nanocomposite with sulfuric acid significantly enhances the activity of the catalyst in the selective hydrogenation of LA to GVL and allows the reaction to proceed under mild reaction conditions (100 °C, 2 MPa of H2) in water and low catalyst loading (0.016 mol.%) with a quantitative yield of GVL and selectivity up to 100%. The catalysts were successfully reused four times without a significant loss of activity. A comprehensive physicochemical characterization of the catalysts allowed us to assess structure-property relationships and to uncover an important role of the polymeric support in the efficient GVL synthesis.

scholarly journals Highly selective electrochemical hydrogenation of alkynes: Rapid construction of mechanochromic materials

2019 ◽  
Vol 5 (5) ◽  
pp. eaaw2774 ◽  
Author(s):  
Bijin Li ◽  
Haibo Ge
Keyword(s):  
Catalytic Reduction ◽  
Supporting Electrolyte ◽  
Environmentally Benign ◽  
Electrochemical Hydrogenation ◽  
X Ray Diffraction ◽  
Rapid Construction ◽  
Simple Alternative ◽  
Hydrogen Carrier ◽  
And Control ◽  
First Time

Electrochemical hydrogenation has emerged as an environmentally benign and operationally simple alternative to traditional catalytic reduction of organic compounds. Here, we have disclosed for the first time the electrochemical hydrogenation of alkynes to a library of synthetically important Z-alkenes under mild conditions with great selectivity and efficiency. The deuterium and control experiments of electrochemical hydrogenation suggest that the hydrogen source comes from the solvent, supporting electrolyte, and base. The scanning electron microscopy and x-ray diffraction experiments demonstrate that palladium nanoparticles generated in the electrochemical reaction act as a chemisorbed hydrogen carrier. Moreover, complete reduction of alkynes to saturated alkanes can be achieved through slightly modified conditions. Furthermore, a series of novel mechanofluorochromic materials have been efficiently constructed with this protocol that showed blue-shifted mechanochromism. This discovery represents the first example of cis-olefins–based organic mechanochromic materials.

Cobalt(II), copper(II), and iron(II) tetrasulfophthalocyanines covalently supported on wool: Synthesis, characterization and catalytic activity

2016 ◽  
Vol 20 (06) ◽  
pp. 677-688 ◽  
Author(s):  
Ahmad Shaabani ◽  
Zeinab Hezarkhani
Keyword(s):  
Catalytic Activity ◽  
Carbonyl Compounds ◽  
Aerobic Oxidation ◽  
Significant Loss ◽  
X Ray Diffraction ◽  
Flame Atomic Absorption Spectroscopy ◽  
X Ray ◽  
Flame Atomic Absorption ◽  
Eds Analysis ◽  
Ft Ir

Functionalized wool with cobalt(II), copper(II), and iron(II) tetrasulfophthalocyanine (CoTSPc@wool, CuTSPc@wool, and FeTSPc@wool) have been synthesized and their structures characterized by flame atomic absorption spectroscopy (FAAS), FT-IR, UV-vis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and the energy dispersive spectroscopy (EDS) analysis. The catalytic activity of the synthesized catalysts was investigated for the aerobic oxidation of alkyl arenes and alcohols to their corresponding carbonyl compounds in the absence of any co-promoter and additional oxidizing reagent. We found the best catalyst for the mentioned reactions is the CoTSPc@wool from the solvent, conversion, temperature, and reaction time point of views. The synthesized catalysts can be readily recycled and reused for several runs without significant loss of efficiency.

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