نتایج جستجو برای: Pechmann condensation

تعداد نتایج: 32400  

Journal: :Molecules 2017
Souad Bouasla Juan Amaro-Gahete Dolores Esquivel M Isabel López César Jiménez-Sanchidrián Mabrouk Teguiche Francisco J Romero-Salguero

A suitable methodology of synthesis of coumarin derivatives by Pechmann reaction over heterogeneous solid acid catalysts in a free solvent media under microwave irradiation is described. Resorcinol, phenol and ethyl acetoacetate were selected as model reactants in the Pechmann condensation. The catalytic activity of several materials-Amberlyst-15, zeolite β and sulfonic acid functionalized hybr...

2013
Mariya Shamzhy Maksym Opanasenko Oleksiy Shvets Jiří Čejka

Catalytic behavior of isomorphously substituted B-, Al-, Ga-, and Fe-containing extra-large pore UTL zeolites was investigated in Knoevenagel condensation involving aldehydes, Pechmann condensation of 1-naphthol with ethylacetoacetate, and Prins reaction of β-pinene with formaldehyde and compared with large-pore aluminosilicate zeolite beta and representative Metal-Organic-Frameworks Cu3(BTC)2 ...

Journal: :iranian journal of catalysis 2014
khodabakhsh niknam seyed ahmad sajadi roghayeh hosseini mojtaba baghernejad

silica-bonded n-propyldiethylenetriamine sulfamic acid (sbpdsa) was found as an efficient solid acid for the synthesis of coumarins. coumarin derivatives were obtained via the pechmann condensation reaction of phenols and β-keto-esters at 80 oc under solvent-free conditions. also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. t...

Khodabakhsh Niknam, Mojtaba Baghernejad, Roghayeh Hosseini Seyed Ahmad Sajadi

Silica-bonded n-propyldiethylenetriamine sulfamic acid (SBPDSA) was found as an efficient solid acid for the synthesis of coumarins. Coumarin derivatives were obtained via the Pechmann condensation reaction of phenols and β-keto-esters at 80 oC under solvent-free conditions. Also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. T...

Khodabakhsh Niknam, Mojtaba Baghernejad, Roghayeh Hosseini Seyed Ahmad Sajadi

Silica-bonded n-propyldiethylenetriamine sulfamic acid (SBPDSA) was found as an efficient solid acid for the synthesis of coumarins. Coumarin derivatives were obtained via the Pechmann condensation reaction of phenols and β-keto-esters at 80 oC under solvent-free conditions. Also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. T...

Journal: :Malaysian Journal of Science Health & Technology 2021

Coumarin and its derivatives represent one of the most active curriculums compound possessing a broad spectrum biological activity along with other applications such as insecticide fragrance. There are various methodologies developed for synthesis coumarins. Classical routes to coumarins include Pechmann condensation, Knoevenagel Perkin reaction, Wittig condensation reactions. Researchers have ...

Elham Tahanpesar, Leila Sarami

The Pechmann condensation has been used as a simple and efficient method for the preparation of coumarin derivatives, which phenols and ethyl acetoacetate were reacted in the presence of AlCl3 supported on nano silica as an efficient catalyst at 110 oC under solvent free condition to form products with good to excellent yield (55 -90%), which are identified by spectroscopic method ( FT-IR, NMR)...

Elham Tahanpesar, Leila Sarami

The Pechmann condensation has been used as a simple and efficient method for the preparation of coumarin derivatives, which phenols and ethyl acetoacetate were reacted in the presence of AlCl3 supported on nano silica as an efficient catalyst at 110 oC under solvent free condition to form products with good to excellent yield (55 -90%), which are identified by spectroscopi...

2013
Yashumati R. Bhardwaj Monika Chauhan Ashutosh Pareek Dharma Kishore

Present work describes the synthesis of coumarin Mannich bases 4-7 by the application of Mannich reaction on 7-hydroxy-4-methyl coumarin 3 using conventional as well as microwave technology to compare the feasibility, reaction time and yield of the product. For this, 7-hydroxy-4-methyl coumarin 3 was prepared using Pechmann condensation reaction and Mannich bases (4-7) were synthesized by the r...

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