scholarly journals Bio-Waste Curd Water as a Greener Protocol for the Synthesis of Biginelli Products at Ambient Temperature

2021 ◽  
Vol 5 (2) ◽  
Keyword(s):  
Waste Water ◽  
Biginelli Reaction ◽  
Product Formation ◽  
Green Solvent ◽  
Reaction Conditions ◽  
Short Reaction Time ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Continuous Product ◽  
Successive Method

A highly efficient, greener and reusable protocol has been developed for the Biginelli reaction. The biowaste curd water employed as a green solvent as well as catalyst for the synthesis of dihydropyrimidinones derivatives. The soluble organic acid (i.e. lactic acid) responsible for the acidity to curd water which adequately fulfills the purpose of acid catalyzed reaction, where three component coupling of aldehyde, urea and ethyl acetoacetate reacted together in the presence of curd water at a low temperature and yields classical dihydropyrimidinones derivatives. During the reaction, continuous product formation and isolation was observed. The product precipitate was separated by the successive method of filtration. This bio-waste water catalyzed method is highly retrievable and advantageous over the trend of high-temperature Bronsted acid/metal acid catalyzed reactions offering the product. Compared with the classical Biginelli reaction conditions, this new method has the advantage of good yields (76-82%) and short reaction time (2-3 hours)

Efficient Copper-Catalyzed Synthesis of Substituted Pyrazoles at Room Temperature

Synlett ◽  
2018 ◽  
Vol 29 (20) ◽  
pp. 2689-2692 ◽  
Author(s):  
Haifeng Wang ◽  
Xiangli Sun ◽  
Shuangling Zhang ◽  
Guanglu Liu ◽  
Chunjie Wang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Catalytic System ◽  
Efficient Method ◽  
Room Temperature ◽  
Copper Catalyst ◽  
Condensation Reaction ◽  
Reaction Conditions ◽  
Short Reaction Time ◽  
Acid Catalyzed ◽  
Substituted Pyrazoles

An efficient method for the synthesis of pyrazoles through a copper-catalyzed condensation reaction has been developed. The new catalytic system not only maintained a broad substrate scope but was also active under acid-free reaction conditions, overcoming the conventional requirement for an acid-catalyzed system. Furthermore, the copper catalyst enabled this reaction to be performed at room temperature and in a short reaction time.

Notizen: High Pressure Reactions, I Evidence for Two Concurrent Mechanisms in Lewis-Acid Catalyzed Alkylation of Aromatics with Olefins

1976 ◽  
Vol 31 (2) ◽  
pp. 277-278 ◽  
Author(s):  
H. Tiltscher ◽  
R. Lohmüller
Keyword(s):  
High Pressure ◽  
Pressure Range ◽  
Reaction Rate ◽  
Initial Reaction Rate ◽  
Product Formation ◽  
Initial Reaction ◽  
Homogeneous Reaction ◽  
Reaction Conditions ◽  
Alkylation Of Benzene ◽  
Acid Catalyzed

A kinetic study was made of the primary step of the alkylation of benzene with propylene and ferric chloride as catalyst under homogeneous reaction conditions at several pressures up to 2 kbar. Initial reaction rate of cumene formation shows a minimum in the medium pressure range, thus indicating that product formation occurs via two different reaction paths with opposite pressure dependence.

scholarly journals One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Catalyzed by Chlorosulfonic Acid

2005 ◽  
Vol 2 (4) ◽  
pp. 228-230 ◽  
Author(s):  
Jin Tong-Shou ◽  
Zhao Ying ◽  
Liu Li-Bin ◽  
Li Tong-Shuang
Keyword(s):  
Reaction Time ◽  
Biginelli Reaction ◽  
Chlorosulfonic Acid ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
Short Reaction Time ◽  
One Pot Synthesis

An efficient synthesis of 3,4-dihydropyrimidin-2-ones (DHPMs) from the aldehydes, β-ketoesters and urea in ethanol using chlorosulfonic acid as the catalyst is described. Compared with the classical Biginelli reaction conditions, this method has the advantage of excellent yields and short reaction time.

scholarly journals Hydrothermal Depolymerization of Biorefinery Lignin-Rich Streams: Influence of Reaction Conditions and Catalytic Additives on the Organic Monomers Yields in Biocrude and Aqueous Phase

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1241 ◽  
Author(s):  
Stefano Dell’Orco ◽  
Edoardo Miliotti ◽  
Giulia Lotti ◽  
Andrea Maria Rizzo ◽  
Luca Rosi ◽  
...  
Keyword(s):  
Aqueous Phase ◽  
Subcritical Water ◽  
Reaction Medium ◽  
Chemical Extraction ◽  
Batch Reactors ◽  
Reaction Conditions ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Biphasic Medium ◽  
Catalytic Additives

Hydrothermal depolymerization of lignin-rich streams (LRS) from lignocellulosic ethanol was successfully carried out in a lab-scale batch reactors unit. A partial depolymerization into oligomers and monomers was achieved using subcritical water as reaction medium. The influence of temperature (300–350–370 °C) and time (5–10 minutes) was investigated to identify the optimal condition on the monomers yields in the lighter biocrude (BC1) and aqueous phase (AP) fractions, focusing on specific phenolic classes as well as carboxylic acids and alcohols. The effect of base catalyzed reactions (2–4 wt. % of KOH) was compared to the control tests as well as to acid-catalyzed reactions obtained with a biphasic medium of supercritical carbon dioxide (sCO2) and subcritical water. KOH addition resulted in enhanced overall depolymerization without showing a strong influence on the phenolic generation, whereas sCO2 demonstrated higher phenolic selectivity even though no effect was observed on the overall products mass yields. In conclusion, a comparison between two different biocrude collection procedures was carried out in order to understand how the selected chemical extraction mode influences the distribution of compounds between BC1 and AP.

scholarly journals Biochar-Based Graphitic Carbon Nitride Adorned with Ionic Liquid Containing Acidic Polymer: A Versatile, Non-Metallic Catalyst for Acid Catalyzed Reaction

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5958
Author(s):  
Samahe Sadjadi ◽  
Fatemeh Koohestani ◽  
Majid Heravi
Keyword(s):  
Ionic Liquid ◽  
Carbon Nitride ◽  
Knoevenagel Condensation ◽  
Biginelli Reaction ◽  
Aqueous Media ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Metallic Catalyst ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

A novel biochar-based graphitic carbon nitride was prepared through calcination of Zinnia grandiflora petals and urea. To provide acidic and ionic-liquid functionalities on the prepared carbon, the resultant biochar-based graphitic carbon nitride was vinyl functionalized and polymerized with 2-acrylamido-2-methyl-1-propanesulfonic acid, acrylic acid and the as-prepared 1-vinyl-3-butylimidazolium chloride. The final catalytic system that benefits from both acidic (–COOH and –SO3H) and ionic-liquid functionalities was applied as a versatile, metal-free catalyst for promoting some model acid catalyzed reactions such as Knoevenagel condensation and Biginelli reaction in aqueous media under a very mild reaction condition. The results confirmed high activity of the catalyst. Broad substrate scope and recyclability and stability of the catalyst were other merits of the developed protocols. Comparative experiments also indicated that both acidic and ionic-liquid functionalities on the catalyst participated in the catalysis.

scholarly journals Acid-catalyzed rearrangements in arenes: interconversions in the quaterphenyl series

2019 ◽  
Vol 15 ◽  
pp. 2655-2663
Author(s):  
Sarah L Skraba-Joiner ◽  
Carter J Holt ◽  
Richard P Johnson
Keyword(s):  
Complex Network ◽  
High Field ◽  
Product Formation ◽  
Nmr Analysis ◽  
Thermodynamic Control ◽  
Implicit Solvation ◽  
Reaction Conditions ◽  
Microwave Reactor ◽  
Acid Catalyzed ◽  
Sole Product

Arenes undergo rearrangement of phenyl, alkyl, halogen and other groups through the intermediacy of ipso arenium ions in which a proton is attached at the same carbon as the migrating substituent. Interconversions among the six quaterphenyl isomers have been studied here as a model for rearrangements of linear polyphenyls. All reactions were carried out in 1 M CF3SO3H (TfOH) in dichloroethane at 150 °C in a microwave reactor for 30–60 min, with product formation assessed by high field NMR analysis. Under these reaction conditions, m,p'-quaterphenyl is the equilibrium product. This isomer is unchanged by the reaction conditions and all other quaterphenyl isomers rearrange to m,p' as the dominant or sole product. DFT computations with inclusion of implicit solvation support a complex network of phenyl and biphenyl shifts, with barriers to rearrangement in the range of 10–21 kcal/mol. Consistent with experiments, the lowest energy arenium ion located on this surface is due to protonation of m,p'-quaterphenyl. This supports thermodynamic control based on carbocation energies.

One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-Ones Using Cadmium Sulfate as Catalyst

2003 ◽  
Vol 2003 (9) ◽  
pp. 544-545 ◽  
Author(s):  
Shujang Tu ◽  
Fang Fang ◽  
Chunbao Miao ◽  
Hong Jiang ◽  
Daqing Shi ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Reaction Time ◽  
Biginelli Reaction ◽  
Aromatic Aldehydes ◽  
New Method ◽  
Reaction Conditions ◽  
One Pot ◽  
Cadmium Sulfate ◽  
Short Reaction Time ◽  
Effective Synthesis

A simple effective synthesis of 3,4-dihydropyrimidin-2(1 H)-one derivatives from aromatic aldehydes, 1,3-dicarbonyl compounds and urea in glacical acetic acid using cadmium sulfate as catalyst is described and compared with the classical Biginelli reaction conditions, this new method has the advantage of excellent yields (83–94%) and short reaction time (2-4 h).

Naturally Occurring Organic Acid-catalyzed Facile Diastereoselective Synthesis of Biologically Active (E)-3-(arylimino)indolin-2-one Derivatives in Water at Room Temperature

2019 ◽  
Vol 23 (16) ◽  
pp. 1778-1788 ◽  
Author(s):  
Gurpreet Kaur ◽  
Arvind Singh ◽  
Kiran Bala ◽  
Mamta Devi ◽  
Anjana Kumari ◽  
...  
Keyword(s):  
Room Temperature ◽  
Biologically Active ◽  
Environmentally Benign ◽  
Diastereoselective Synthesis ◽  
Substituted Anilines ◽  
Reaction Conditions ◽  
Naturally Occurring ◽  
Acid Catalyzed ◽  
Reaction Media ◽  
Column Chromatographic

A simple, straightforward and efficient method has been developed for the synthesis of (E)-3-(arylimino)indolin-2-one derivatives and (E)-2-((4-methoxyphenyl)imino)- acenaphthylen-1(2H)-one. The synthesis of these biologically-significant scaffolds was achieved from the reactions of various substituted anilines and isatins or acenaphthaquinone, respectively, using commercially available, environmentally benign and naturally occurring organic acids such as mandelic acid or itaconic acid as catalyst in aqueous medium at room temperature. Mild reaction conditions, energy efficiency, good to excellent yields, environmentally benign conditions, easy isolation of products, no need of column chromatographic separation and the reusability of reaction media are some of the significant features of the present protocol.

Ascorbic acid-Catalyzed One-Pot Three-Component Biginelli Reaction: A Practical and Green Approach towards Synthesis of 3,4-dihydropyrimidin- 2(1H)-ones/thiones

2013 ◽  
Vol 10 (7) ◽  
pp. 463-467 ◽  
Author(s):  
Imene Sehout ◽  
Raouf Boulcina ◽  
Boudjemaa Boumoud ◽  
Fabienne Berree ◽  
Bertrand Carboni ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Biginelli Reaction ◽  
One Pot ◽  
Green Approach ◽  
Acid Catalyzed

Photoinduced rearrangement of hydroxymethylisoxazolines, a route to enaminoaldehydes

1986 ◽  
Vol 51 (10) ◽  
pp. 2167-2180 ◽  
Author(s):  
Lubor Fišera ◽  
Nadezhda D. Kozhina ◽  
Peter Oravec ◽  
Hans-Joachim Timpe ◽  
Ladislav Štibrányi ◽  
...  
Keyword(s):  
Thionyl Chloride ◽  
Quantum Yields ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Photoinduced Rearrangement ◽  
Condensed Heterocycles

3-Aryl-4-R-carbamoyl-5-hydroxymethylisoxazolines (IV) were synthesized by allowing R-NH2 amines with R = H, CH3, C3H7, C6H5C2H5, and NH2 to act on 3-(X-phenyl)-4-oxo-3a,4,6,6a-tetrahydrofuro[3,4-d]isoxazoles (III) with X = H, 4-CH3, 4-OCH3, 2-OCH3, 4-Cl, 2-Cl, 4-F, 2-F, 4-Br, 4-NO2, and 3-NO2. Exposed to radiation, the substances IV give Z-2-hydroxymethylamino-2-aryl-1-formylacrylamides (V) in good yields. The 4-Cl and 4-F substituted Z-derivatives V isomerize irreversibly to the E-derivatives VI if allowed to stand in solvent; the remaining derivatives V are stable. The quantum yields of the photoreaction are from 0.012 to 0.106 in dependence on the substituent X. In all cases where the compounds IV were used for the preparation of condensed heterocycles in conditions of acid-catalyzed reactions, lactones III were preferentially formed; the action of thionyl chloride on IV results in the formation of chloromethyl derivatives VIII, which do not undergo further cyclization.

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