Synthesis of 5-benzylidene-hydantoin and 5-benzylidene-creatinine derivatives under mixed catalyst systems of urea-p-toluenesulfonic acid (Urea-PTSA) and guanidine hydrochloride-triethylamine (GnHCl-TEA)

摘要

Derivatives of 5-benzylidenehydantion are well known of their various attractive bioactivities such as anticancer, antimicrobial, antidiabetic and tyrosinase inhibitor. The preparation methods of 5-benzylidenehydantoin and 5- benzylidenecreatinine derivatives obtained from the reaction between aromatic aldehydes with hydantoin or creatinine using Knoevenagel condensation are discussed. Performing the reactions, we used mixed catalysts system that were Urea- p-Toluene sulfonic acid (Urea-PTSA) and Guanidine hydrochloride-triethylamine (GnHCl-TEA) in polyethylene glycol as solvent. The reaction conditions were suitable for the reaction of aromatic aldehydes attaching electron donating substituent, as well as electron withdrawing substituents. Catalyst system of Urea-PTSA furnished best yield for rich electron aldehydes, while catalyst system of GnHCl-TEA were suitable for poor electron aldehydes and heteroaromatic aldehydes.