solvent-free mechanochemical green synthesis of schiff bases of tranexamic acid and study of their urease inhibitory and antioxidant activities

three schiff bases of tranexamic acid were successfully synthesized by a mechanochemical green method, which is 4-{(5-bromo-2- hydroxybenzylidene)amino]methyl}cyclohexanecarboxylic acid (sb1), 4-{(2-hydroxybenzylidene)amino]methyl}cyclohexanecarboxylic acid (sb2), and 4-{(4-nitrobenzylidene)amino]methyl}cyclohexanecarboxylic acid (sb3) in good yield. their structures were confirmed based on spectroscopic data. the bases displayed considerable urease inhibitory activity with ic50 (μg/ml) 33.41, 40.64, 26.18, and 11.14 for sb1, sb2, sb3, and standard thiourea, respectively. they revealed weak antiradical activity in dpph assay with ec50 (μg/ml) 1138, 1239, and 24248 for sb1, sb2, and sb3, respectively. in conclusion, grinding is an efficient and environmentally friendly method for synthesizing these bases, which may provide potential candidates for new medicines.