The synthesis of coumarin derivatives using choline chloride/zinc chloride as a deep eutectic solvent

Environmentally Friendly Approach to Knoevenagel Condensation of Rhodanine in Choline Chloride: Urea Deep Eutectic Solvent and QSAR Studies on Their Antioxidant Activity

“…Their application in organic synthesis includes synthesis of different heterocycles [ 6 , 7 , 8 , 9 , 10 ], esterification [ 11 ], aldol reactions [ 12 ], halogenation [ 13 ] as well as N -acetylation of amines [ 14 ], synthesis of mercapto quinazolinones [ 15 ], and Schiff bases [ 16 ], all performed by our group. Knoevenagel condensation in deep eutectic solvents has been studied by Keshavarzipour and Tavakol [ 17 ], indicating that DESs could be a very useful tool in this type of condensation. Knoevenagel condensation has been employed in the synthesis of numerous heterocyclic compounds, and is one of the basic reactions in organic chemistry.…”

Recent Advances in the Synthesis of Coumarin Derivatives from Different Starting Materials

“…Keshavarzipour and Tavakol [65] disclosed the green synthesis of coumarin derivatives in deep eutectic solvent (DES) by Knoevenagel condensation. DES was prepared by mixing choline chloride (ChCl) and zinc chloride at 100 • C. For the synthesis of coumarins derivatives, simple or substituted salicylaldehydes (4-hydroxy, 5-bromo) and methylene compounds (dimethyl malonate, ethyl cyanoacetate, ethyl 3-oxo-3-phenylpropanoate) were used (Scheme 1).…”

“…Keshavarzipour and Tavakol [65] disclosed the green synthesis of coumarin derivatives in deep eutectic solvent (DES) by Knoevenagel condensation. DES was prepared by mixing choline chloride (ChCl) and zinc chloride at 100 °C.…”

One-pot multicomponent synthesis of thieno[2,3-b]indoles catalyzed by a magnetic nanoparticle-supported [Urea]4[ZnCl2] deep eutectic solvent

“…[16][17][18][19][20] However, signicant drawbacks including difficult catalyst recovery, tedious product separation, and the requirement of greater stoichiometric amounts of DES as dual catalyst/solvent limited their widespread application. 15,[21][22][23] Hence, the idea for using supported DES always exists in our mind, which combines the prominent feature of DES and the benets of heterogeneous catalysts, including ease of handling, separation, and recycling. Magnetic nanoparticles (MNPs) have recently been shown to be catalyst supports due to their easy preparation, low cost, high stability, high surface area, and simple recovery by magnetic forces.…”