scholarly journals Allyl type monomers for hard surface coating protection

2019 ◽  
Vol 140 ◽  
pp. 02007
Author(s):  
Larisa Popova ◽  
Anzhelika Tsyrulnikova ◽  
Sergey Vershilov ◽  
Julia Bazarnova ◽  
Ekaterina Aronova ◽  
...  
Keyword(s):  
Tetrabutylammonium Bromide ◽  
Environmental Safety ◽  
Carbon Chain ◽  
High Yield ◽  
Main Reaction ◽  
Fibrous Materials ◽  
Series Of Experiments ◽  
Work Up ◽  
Derivatives Of ◽  
Improve Mass Transfer

Based on the unsaturated derivatives of polyfluoroalkanols chemical products are used to protect solid and fibrous materials surface from the effects of water, oils and other pollutants. A method for obtaining allyl ethers of polyfluoroalkanols (polyfluoroalkoxypropenes) is based on the Williamson ether reaction. This method is a heterophase process. The use of solvents to improve mass transfer requires complementary measures to ensure industrial and environmental safety. It is more preferable to obtain the target ethers in water with PTC. A series of experiments using different chain length polyfluoroalkanols was studied by GLC. Kovats retention indexes of the target ethers were determined. It was found that in the case of lower homologues (CF3CH2OH, (CF3)2CHOH, HCF2CF2CH2OH), the addition of 5-15 vol.% 1,4-dioxane as a solubilizer provides a high yield of products. The application of PTC (tetrabutylammonium bromide) is indispensable for using polyfluoroalkanols with a longer carbon chain (C≥5). PTC invariably provides the almost complete conversion of polyfluoroalkanols. The decomposition process of TBAB becomes noticeable (GLC method) upon completion of the main reaction. Polyfluoroalkoxypropenes form azeotrope with water, which can be used in the work up process.

PEG1000 as a Low Melting and Ecofriendly Solvent for Air Oxidative and Catalyst Free 2,4-Disubstitute Quinazoline Synthesis

2020 ◽  
Vol 17 (9) ◽  
pp. 709-716
Author(s):  
Ebrahim Saeedian Moghadam ◽  
Shahrzad Ghafary ◽  
Mohsen Amini
Keyword(s):  
Melting Point ◽  
High Yield ◽  
Purification Process ◽  
Poly Ethylene Glycol ◽  
Free Condition ◽  
Catalyst Free ◽  
Privileged Scaffold ◽  
Quinazoline Derivatives ◽  
Poly Ethylene ◽  
Work Up

With regard to the importance of quinazoline as a privileged scaffold, herein we report the synthesis of twenty seven 2,4-disubstitute quinazoline derivatives in a new catalyst free condition. In the current work, poly ethylene glycol (PEG1000) as an inexpensive, very simple commercially available, ecofriendly and low melting point solvent was used. Air bubbling, a green oxidant, for oxidation purpose was also used. This is the first report about using PEG1000 as a solvent simultaneously with air bubbling as oxidant in quinazoline synthesis. All of the compounds 1-27 were synthesized in high yield with very simple work up and purification process without using column chromatography. All the structures were confirmed using 1H NMR, 13C NMR, IR, MS and elemental analysis.

4-Hydroxy Pyridinium Triflate@SiO2 Nanoparticles as a Novel Efficient Catalyst for Fries Rearrangement of Aryl Esters with High Selectivity

2020 ◽  
Vol 17 (8) ◽  
pp. 654-660
Author(s):  
Shermineh Sadat Ghalehbandi ◽  
Dadkhoda Ghazanfari ◽  
Sayed Ali Ahmadi ◽  
Enayatollah Sheikhhosseini
Keyword(s):  
High Selectivity ◽  
Sio2 Nanoparticles ◽  
High Yield ◽  
Synthetic Method ◽  
Functionalized Silica ◽  
Efficient Catalyst ◽  
Fries Rearrangement ◽  
Free Condition ◽  
Solvent Free Condition ◽  
Work Up

Introduction: We developed a simple, fast and new method for the Fries rearrangement of aryl esters. Materials and Methods: 4-Hydroxy pyridinium triflate functionalized silica is a very efficient, reusable and economically available catalyst for the Fries rearrangement in solvent-free condition and under microwave irradiation. Results and Discussion: Also, a notable selectivity was observed in the presence of 4-hydroxy pyridinium triflate functionalized silica. Conclusion: Selectivity, shorter reaction time, high yield, and easy work-up are advantages of this synthetic method.

The Pyrolytic Rearrangement of 1-Alkynoyl-3-methylpyrazoles: Synthesis of Pyrazolo[1,5-a]pyridin-5-ols and Related Compounds

1994 ◽  
Vol 47 (6) ◽  
pp. 991 ◽  
Author(s):  
RFC Brown ◽  
FW Eastwood ◽  
GD Fallon ◽  
SC Lee ◽  
RP Mcgeary
Keyword(s):  
Carbon Chain ◽  
Ring Structure ◽  
High Yield ◽  
Methyl Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Fused Ring ◽  
Related Compounds

Flash vacuum pyrolysis of 1-(alkyn-2′-oyl)-3-methylpyrazoles at 650°/0.03 mm forms pyrazolo[1,5-a]pyridin-5-ols, often in high yield, which may bear substituents at C2, C3 or C7. In the absence of a 3-methyl group in the precursor, N-ethynylpyrazoles are formed in low yield. The formation of both types of product is interpreted as involving 3-(N-pyrazolyl)propadienones formed by N1 → N2 migration of the N-alkynoyl group with inversion of the three-carbon chain. The fused-ring structure of 2-methylpyrazolo[1,5-a]pyridin-5-ol (25) was established by X-ray crystallography of the O-benzoyl derivative (27).

An efficient multicomponent, one-pot synthesis of Betti bases catalyzed by cerium (IV) ammonium nitrate (CAN) at ambient temperature

2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Abdullah Mohamed Asiri ◽  
Afaf Mohamed Abdel Hameed ◽  
Reham R. Awed ◽  
Kamal Usef Sadek
Keyword(s):  
Ambient Temperature ◽  
Environmental Pollution ◽  
Ammonium Nitrate ◽  
Room Temperature ◽  
Catalytic Amount ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Work Up ◽  
Cerium Iv Ammonium Nitrate

AbstractStarting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.

scholarly journals Green and efficient three-component synthesis of 4H-pyran catalysed by CuFe 2 O 4 @starch as a magnetically recyclable bionanocatalyst

2020 ◽  
Vol 7 (7) ◽  
pp. 200385
Author(s):  
Maryam Kamalzare ◽  
Mohammad Bayat ◽  
Ali Maleki
Keyword(s):  
Low Cost ◽  
Environmentally Benign ◽  
Pharmaceutical Chemistry ◽  
X Ray Diffraction ◽  
Natural Polymers ◽  
X Ray ◽  
Benign Nature ◽  
Catalytic Behaviour ◽  
Work Up ◽  
Derivatives Of

The development of simple, practical and inexpensive catalysis systems using natural materials is one of the main goals of pharmaceutical chemistry as well as green chemistry. Owing to the ability of easy separation of nanocatalyst, those goals could be approached by applying heterogeneous bionanocatalyst in combination with magnetic nanoparticles. Starch is one of the most abundant natural polymers; therefore, preparing bionanocatalyst from starch is very valuable as starch is largely available and inexpensive. An ecologically benign and efficacious heterogeneous nanocatalyst was prepared based on a biopolymer, and its attributes and morphology were specified by using Fourier transform infrared spectra, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermal analysis and vibrating sample magnetometer measurements; followed by studying catalytic behaviour of bionanocomposite in a multicomponent reaction to synthesize of 4H-pyran derivatives. 4H-pyran is extremely valuable in pharmaceutical chemistry, and the development of methods for synthesis of different derivatives of 4H-pyran is momentous. Revealing environmentally benign nature, mild condition, easy work-up, low cost and non-toxicity are some of the advantages of this protocol. Besides, the bionanocomposite was recovered using an external magnetic bar and could be re-used at least six times with no further decrease in its catalytic activity.

Efficient and Green Synthesis of 2,2′-(Arylmethylene)Bis-4-Pyrones in an Ionic Liquid [bmim+][BF4–]

2017 ◽  
Vol 41 (2) ◽  
pp. 75-78
Author(s):  
Yulan Ren ◽  
Hang Song
Keyword(s):  
Ionic Liquid ◽  
Green Synthesis ◽  
Aromatic Aldehyde ◽  
Ammonium Acetate ◽  
High Yield ◽  
Three Component Reaction ◽  
Work Up

A series of sixteen 2,2′-(arylmethylene)bis(3-hydroxy-6-methyl-4H-pyran-4-ones) have been prepared in high yield via an ammonium acetate-catalysed three-component reaction of an aromatic aldehyde (1 equiv.) and allomaltol (2 equiv.) in an ionic liquid [bmim+][BF4–]. The reaction work-up is simple and the ionic liquid can be easily separated from the product and reused.

scholarly journals Microwave Assisted One Pot Synthesis of 3,4-Dihydropyrano[c]chromene Derivatives using [Emim]OH Ionic Liquid as Novel Catalyst

2019 ◽  
Vol 31 (4) ◽  
pp. 829-833
Author(s):  
D.S. Bhagat ◽  
S.G. Pande ◽  
M.V. Katariya ◽  
R.P. Pawar ◽  
P.S. Kendrekar
Keyword(s):  
Ionic Liquid ◽  
Reaction Time ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Short Reaction Time ◽  
Aryl Aldehydes ◽  
Microwave Assisted ◽  
Novel Catalyst ◽  
Work Up

One-pot efficient protocol to the synthesis of 2-amino-5-oxo-4,5-dihydropyrano(3,2-c)chromene-3-carbonitrile derivatives via condensation of various aryl aldehydes, dicyanomethane and 4-hydroxycoumarin in presence of Emim hydroxide as an excellent homogeneous liquid catalyst. The key advantages of this methodology are mild reaction conditions, novel catalyst, short reaction time, eco-friendly, easy work-up procedure and high yield of isolation of derivatives.

scholarly journals Formation and Thermal Behaviors of Ternary Silicon Oxycarbides derived from Silsesquioxane Derivatives

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1721
Author(s):  
Yoshiaki Iwase ◽  
Teruaki Fuchigami ◽  
Yoji Horie ◽  
Yusuke Daiko ◽  
Sawao Honda ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
Sol Gel ◽  
Silicon Oxycarbide ◽  
High Yield ◽  
Amorphous Sio2 ◽  
Gaseous Hydrocarbon ◽  
Spectroscopic Analyses ◽  
Sio2 Nanocomposites ◽  
Derivatives Of

Silsesquioxane (SQ) derivatives possessing intramolecular H2C = CH- groups and Si-H groups were designed as precursors for ternary silicon oxycarbide (SiOC). By using R-Si(OMe)3, H-Si(OEt)3 and (H-Si(Me)2)2O as starting compounds, SQ derivatives of VH-SQ (R = vinyl) and St-H-SQ (R = stylyl) were successfully synthesized through the conventional sol-gel route. Simultaneous thermogravimetric and mass spectroscopic analyses up to 1000 °C revealed that in situ cross-linking via hydrosilylation and demethanation of VH-SQ suppressed the evolution of gaseous hydrocarbon species to afford amorphous SiOC having a composition close to the desired stoichiometric SiO2(1−x)Cx (x = ca. 0.3) with a high yield. The effect of carbon content on the phase separation and crystallization of the SQ-derived amorphous SiOC was studied by several spectroscopic analyses and TEM observation. The results were discussed aiming to develop a novel polymer-derived ceramics (PDCs) route for in situ formation of binary β-SiC-amorphous SiO2 nanocomposites with enhanced thermal and mechanical stability.

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