Development of industrial efficient asymmetric synthesis of endothelin-A antagonist ABT-546: A case study based on green chemistry perspective

Abstract The catalytic, extremely effective enantioselective conjugate-addition strategy was approved by via 4 mol% of bis(oxazoline)-Mg(OTf)2 along with amine complex as co-catalyst. The magnicium triflate based catalysis afford 88% selectivity in the molecule and provide less dependence on the tartrate salt for enantioselectivity, which was previously prepared for attaining chiral purity for the synthesis of the endothelin-A antagonist ABT-546. Along with enantioselective conjugate-addition the new strategy involves green solvents in the final steps of ABT-546 drug preparation. The use of green solvent owes its own advantage of minimizing the residues remaining in the API synthesized. The article includes the case study of the ABT-546 to discuss the green chemistry objectives fulfilled by pharma industry.