A simple and green procedure for the synthesis of 5-arylidene-4-thiazolidinones by grinding

Two‐Dimensional {Co3+–Co2+} and {Fe3+–Co2+} Networks and Their Heterogeneous Catalytic Activities

“…This reaction is catalyzed by assorted acids,20 bases,21 salts,22 ionic liquids,23 enzymes,24 polymers,25 and even supported catalysts 26. Further, newer techniques including microwave irradiation, supersonic waves, and grinding have also been used to promote this reaction at high temperatures 27,28. Networks 3 and 4 were investigated as heterogeneous catalysts for the Knoevenagel condensation reaction.…”

Tetrabutylammonium bromide and K2CO3: an eco-benign catalyst for the synthesis of 5-arylidene-1,3-thiazolidine- 2,4-diones via Knoevenagel condensation

“…Microwave, [28] ultrasonication [29] and grinding-assisted methods [30] were also utilized to improve the yield of 5-arylidene-1,3-thiazolidine-2,4-diones. However, these methods are associated with limitations, such as low yield, prolonged heating, toxic residues, carcinogenic amines, expensive catalysts and are of important environmental concern.…”

A Simple and Green Procedure for the Synthesis of 5‐Arylidenerhodanines Catalyzed by Diammonium Hydrogen Phosphate in Water

“…Arylidenerhodanines are generally prepared by reacting aldehydes and rhodanine in organic solvents and in the presence of organic bases like piperidine [ 2 , 4 – 8 ]. Recently, catalysts such as 2,2,6,6-tetramethyl piperidine [ 9 , 10 ], NH 4 Cl/NH 4 OH [ 11 ], K 2 CO 3 /[bmim]BF 4 /H 2 O [ 12 ], NaOAc/HOAc [ 3 , 13 , 14 ], glycine [ 15 ], ammonium acetate [ 16 , 17 ], 1-butyl-3-methyl imidazolium hydroxide [ 18 , 19 ], tetrabutylammonium bromide [ 20 ], and K 2 CO 3 /Al 2 O 3 [ 21 ] have been used in this reaction. Although these methods are valuable, most of them suffer from some disadvantages such as a long reaction time, low yields, the use of toxic solvent, expensive catalyst, requiring a promoter, such as microwave, and tedious work-up procedures.…”