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 improvement of lipase secretion and stability by addition of inert compounds into Acinetobacter calcoaceticus cultures

2002 ◽  
Vol 48 (12) ◽  
pp. 1056-1061 ◽  
Author(s):  
Daniela A Martinez ◽  
B Clara Nudel
Keyword(s):  
Enzyme Activity ◽  
Gum Arabic ◽  
Acinetobacter Calcoaceticus ◽  
Glass Beads ◽  
High Yield ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
Cell Fractions ◽  
Triton X ◽  
Effective Additive

Acinetobacter calcoaceticus BD413 produces variable amounts of an exocellular lipase that becomes rapidly inactivated upon secretion. To achieve high yield and protect the enzyme, we assayed the addition of several inert compounds to cell-free supernatants, cell fractions, and whole cultures. Glass beads, poly(ethylene glycol) 600, Triton X-100, saccharose, gum arabic, and β-cyclodextrin were among the compounds tested. β-Cyclodextrin and gum arabic (and saccharose to a lesser extent) were effective enzyme stabilizers in cell-free supernatants, while gum arabic, glass beads, and Triton X-100 improved lipase secretion from cells, and, therefore, total lipase yield (30–50%, according to the additive). In whole cultures, β-cyclodextrin was the most effective additive, particularly in combination with glass beads or gum arabic. Indeed, cultures containing β-cyclodextrin plus gum arabic were able to maintain 95% (±1.5%) of the initial lipase activity for more than 16 h, while control cultures with no additives maintained only 10% (±4%) of the enzyme activity after the same period. In conclusion, the addition of inert compounds in cultures may be considered a useful approach for achieving increased yield and lipase stabilization, amenable for downstream processing.Key words: Acinetobacter calcoaceticus, lipase, secretion, stabilization, inert additives.

Hydroxy-Assisted Catalyst-Free Michael Addition—Dehydroxylation of Baylis—Hillman Adducts in Poly(ethylene glycol).

ChemInform ◽  
2006 ◽  
Vol 37 (31) ◽  
Author(s):  
S. Chandrasekhar ◽  
B. Saritha ◽  
V. Jagadeswar ◽  
Ch. Narsihmulu ◽  
Dolly Vijay ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Michael Addition ◽  
Poly Ethylene Glycol ◽  
Catalyst Free ◽  
Poly Ethylene

Poly(ethylene glycol): an Alternative Solvent for the Synthesis of Cyclic Carbonate from Vicinal Halohydrin and Carbon Dioxide

2009 ◽  
Vol 62 (8) ◽  
pp. 917 ◽  
Author(s):  
Jing-Lun Wang ◽  
Liang-Nian He ◽  
Xiao-Yong Dou ◽  
Fang Wu
Keyword(s):  
Carbon Dioxide ◽  
Ethylene Glycol ◽  
Reaction Medium ◽  
Cyclic Carbonate ◽  
High Yield ◽  
Cyclic Carbonates ◽  
Poly Ethylene Glycol ◽  
Potential Applications ◽  
Ready Availability ◽  
Poly Ethylene

Poly(ethylene glycol) (PEG) in this work proved to be an efficient reaction medium for the reaction of vicinal halohydrin with carbon dioxide in the presence of a base to synthesise cyclic carbonates. Notably, PEG-400 as an environmentally friendly solvent exhibits a unique influence on reactivity compared with conventional organic solvents. Various cyclic carbonates were prepared in high yield employing this protocol. The process presented here has potential applications in the industrial production of cyclic carbonates because of its simplicity, cost benefits, ready availability of starting materials, and mild reaction conditions.

scholarly journals Friedel–Crafts-Type Alkylation of Indoles in Water Using Amphiphilic Resin-Supported 1,10-Phenanthroline–Palladium Complex under Aerobic Conditions

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 193
Author(s):  
Toshimasa Suzuka ◽  
Yuto Ooshiro ◽  
Kazuhito Ogihara
Keyword(s):  
High Selectivity ◽  
Palladium Complex ◽  
Palladium Complexes ◽  
High Yield ◽  
Alkylation Reaction ◽  
Poly Ethylene Glycol ◽  
Aerobic Conditions ◽  
Palladium Catalyzed ◽  
Poly Ethylene ◽  
Polymeric Catalyst

The palladium-catalyzed Friedel-Crafts-type alkylation of indoles in water has been achieved using amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin-supported phenanthroline-palladium complexes in water under aerobic conditions, affording the corresponding products with good-to-high yield. The polymeric catalyst was also found to promote the C3-alkylation reaction to give a thermodynamic alkylation product with high selectivity. The polymeric catalyst was recovered and reused several times without any loss of catalytic activity.

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