Acid catalyzed coupling of aromatic aldehydes and methyldiazoacetate––a theoretical mechanistic study

2012 ◽  
Vol 36 (3) ◽  
pp. 781 ◽  
Author(s):  
Georg Dazinger ◽  
Karl A. Kirchner
Keyword(s):  
Aromatic Aldehydes ◽  
Mechanistic Study ◽  
Acid Catalyzed

DFT Study and Synthesis of Novel Bioactive Bispyrazole Using Mg/AlLDH as a Solid Base Catalyst

2020 ◽  
Vol 14 ◽  
Author(s):  
Soufiane Akhramez ◽  
Youness Achour ◽  
Mustapha Diba ◽  
Lahoucine Bahsis ◽  
Hajiba Ouchetto ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Experimental Finding ◽  
Biological Activities ◽  
Condensation Reaction ◽  
Aromatic Aldehydes ◽  
Mechanistic Study ◽  
Knoevenagel Reaction ◽  
Solid Base ◽  
Reaction Conditions ◽  
Aryl Aldehyde

Background: In this study, an efficient synthesis of novel bispyrazole heterocyclic molecules by condensation of substituted aromatic aldehydes with 1,3-diketo-N-phenylpyrazole by using Mg/Al-LDH as heterogeneous catalyst is reported. The attractive features of this protocol are as follows: mild reaction conditions, good yields and easiness of the catalyst separation from the reaction mixture. Further, a mechanistic study has been performed by using DFT calculations to explain the observed selectivity of the condensation reaction between aryl aldehyde and 1,3-diketo-N-phenylpyrazole via Knoevenagel reaction. The local electrophilicity/ nucleophilicity that allows explaining correctly the experimental finding. Methods: The bispyrazole derivatives 3a-m were prepared by condensation reaction of substituted aromatic aldehydes with 1,3-diketo-Nphenylpyrazole by using Mg/Al-LDH as heterogeneous catalyst under THF solvent at the refluxing temperature. Objective: To synthesize a novel bispyrazole heterocyclic molecule may be have important biological activities and thus can be good candidates for pharmaceutical applications. Results: This protocol describes the Synthesis of Bioactive Compounds under mild reaction conditions, good yields and easiness of the catalyst separation from the reaction mixture. Further, a mechanistic study has been performed by using DFT calculations to explain the observed selectivity of the condensation reaction between aryl aldehyde and 1,3-diketo-N-phenylpyrazole via Knoevenagel reaction. The local electrophilicity/ nucleophilicity that allows explaining correctly the experimental finding. Conclusion: In summary, the pharmacologically interesting bis-pyrazole derivatives have been synthesized through Mg/Al-LDH as a solid base catalyst, in THF as solvent. Thus, the synthesized bioactive compounds containing the pyrazole ring may be have important biological activities and thus can be good candidates for pharmaceutical applications. Therefore, the catalyst Mg/Al-LDH showed high catalytic activity. Besides, a series of bispyrazole molecules were synthesized with a good yield and easy separation of the catalyst by simple filtration. Moreover, DFT calculations and reactivity indexes are used to explain the selectivity of the condensation reaction between aryl benzaldehyde and 1,3-diketo-Nphenylpyrazole via Knoevenagel reaction, and the results are in good agreement with the experimental finding.

The question of Friedel-Crafts transformylations. Acid-catalyzed reactions of aromatic aldehydes with arenes

1987 ◽  
Vol 52 (8) ◽  
pp. 1591-1599 ◽  
Author(s):  
Royston M. Roberts ◽  
Ahmed M. El-Khawaga ◽  
Kevin M. Sweeney ◽  
Maher F. El-Zohry
Keyword(s):  
Aromatic Aldehydes ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

SiO2·12WO3·24H2O: a Highly Efficient Catalyst for the Synthesis of 5-Arylidene Barbituric Acid in the Presence of Water

2009 ◽  
Vol 62 (4) ◽  
pp. 353 ◽  
Author(s):  
Ji-Tai Li ◽  
Ming-Xuan Sun
Keyword(s):  
Room Temperature ◽  
Barbituric Acid ◽  
Aqueous Media ◽  
Aromatic Aldehydes ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
Efficient Route ◽  
Acid Catalyzed ◽  
High Yields

The condensation of aromatic aldehydes and barbituric acid catalyzed by SiO2·12WO3·24H2O in aqueous media at room temperature gave 5-arylidene barbituric acid in high yields with or without the use of ultrasound, providing a simple and efficient route to synthesis of these compounds.

scholarly journals Acid catalyzed synthesis of 2-(2-aminophenyl)quinazoline-4-amine and reaction with aromatic aldehydes

RSC Advances ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 6138-6143 ◽  
Author(s):  
Elina Marinho ◽  
M. Fernanda Proença
Keyword(s):  
Microwave Irradiation ◽  
Aromatic Aldehydes ◽  
Conventional Heating ◽  
Hydrochloride Salt ◽  
Acid Catalyzed

The hydrochloride salt of 2-(2-aminophenyl)quinazoline-4-amine, prepared from a quinazolino[3,4-a]quinazoline, was reacted with aromatic aldehydes under conventional heating or microwave irradiation, leading to tetracyclic dihydroquinazolines.

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