A process for the p reparation of a synthetic tanning a gent is disclosed whereby multi functional polymer is polymerized with sulfonated aromatic compound, pretreated with organic ligand to form an organo-polymeric matrix, free from formaldehyde. The product has potential application in leather industry for not only ensuring an eco-friendly approach in chrome tanning by way of eliminating the conventional pickling process and the resulting problem of total dissolved solids (TDS) associated with the effluent, but also suggesting an exhaust aid for chrome because of its multiple carboxyl groups. The product can also be used as a retanning agent in leather processing.