Some 2-iminothiazolidin-4-ones have been synthesized by the reaction of dialkyl acetylenedicarboxylates with thiosemicarbazones. The reaction was performed in the presence of 10 mol% of triphenylphosphine and tetrabutylammonium bromide as a phase transfer catalyst in water as a green solvent. All the synthesized compounds were characterized by their physical and spectral data.
p-Dodecylbenzenesulfonic acid (DBSA) was used as a catalyst for a simple and efficient one-pot synthesis of aryl substititued tetrahydrobenzo[b]pyrans and dihydropyrano[c]chromens via initial Knoevenagel, subsequent Micheal and final heterocyclization reactions of aryl aldehyde, malononitrile and 4-hydroxycoumarin/dimedone in moderate to excellent yields. The present method was operationally simple and use of water as the reaction medium […]
A series of arylidine barbituric acid derivatives was synthesized by Knoevenagel condensation reaction of aromatic aldehydes with barbituric acid or thiobarbituric acid using dodecylbenzenesulfonic acid as a Brønsted acid-surfactant catalyst in aqueous media. Regardless of the nature of the substitution (electron-donating and -withdrawing), all the reactions were completed within 15-65 min in water at reflux […]
