An extensive study of coumarin synthesis via Knoevenagel condensation in choline chloride based deep eutectic solvents (CROSBI ID 273819)
Prilog u časopisu | izvorni znanstveni rad | međunarodna recenzija
Podaci o odgovornosti
Lončarić, Melita ; Sušjenka, Martina ; Molnar, Maja
hrvatski
An extensive study of coumarin synthesis via Knoevenagel condensation in choline chloride based deep eutectic solvents
Aim and Objective: In order to preserve the environment from harmful organic solvents, a synthesis of coumarin derivatives was performed in deep eutectic solvents, which are considered as “green” due to their characteristics. Materials and Methods: Choline chloride based deep eutectic solvents (DESs) were employed, both as solvents and as catalysts, in the synthesis of coumarin derivatives via Knoevenagel condensation. In order to find the best DES for coumarin synthesis, 20 DESs were tested for the reaction of salicylaldehyde and dimethyl malonate at 80 °C. Results: Among twenty tested deep eutectic solvents only five were adequate for this kind of synthesis. The best DES for this reaction was found to be the one composed of choline chloride:urea (1:2). Most coumarin compounds were obtained in good to excellent yield. Compounds 1g, 2g and 2p should be pointed out due to their yields of 85, 88 and 98 %, respectively. 3- Acetylcoumarins 5a, 5c, 5d, 5e, 5f and 5g were synthesized under ultrasound irradiation and were also obtained in excellent yields of 90, 95, 98, 93, 94 and 85 %, respectively. Conclusion: Series of coumarin derivatives were successfully synthesized, either in choline chloide:urea DES at 80 °C or in ultrasound assisted reaction, from different salicylaldehydes and active methylene compounds. These “green” methods were found to be very effective in Knoevenagel condensation, while DES was recycled for several cycles without any significant influence on the product yield.
coumarins ; synthesis ; deep eutectic solvents ; green chemistry
nije evidentirano
engleski
An extensive study of coumarin synthesis via Knoevenagel condensation in choline chloride based deep eutectic solvents
nije evidentirano
coumarins ; synthesis ; deep eutectic solvents ; green chemistry
nije evidentirano
Podaci o izdanju
17 (2)
2020.
98-108
objavljeno
1570-1794
1875-6271
10.2174/1570179417666200116155704
Povezanost rada
Kemija, Prehrambena tehnologija