Visible-light-driven photocatalysis for the sustainable synthesis of (±)-pregabalin using carbon nitride from melamine-cyanuric acid complex

The pharmaceutical industry has long sought efficient and environmentally sustainable methods for the synthesis of pharmaceutically significant molecules, particularly potent γ-amino butyric acid (GABA) derivatives. Photocatalysis has emerged as a promising approach, offering mild reaction conditions and utilizing renewable energy sources. In this study, we present a novel and sustainable photocatalytic strategy for the synthesis of (±)-pregabalin, a valuable GABA derivative, using carbon nitride derived from the complex of melamine and cyanuric acid (CN-MC) as the catalyst. Under visible light irradiation, CN-MC demonstrated outstanding photocatalytic performance, achieving an excellent 99% yield in the visible-light-driven decarboxylative radical conjugate addition. The formed β-substituted γ-lactam intermediate serves as a crucial building block for the synthesis of (±)-pregabalin. Moreover, the recyclability and scalability of CN-MC as a photocatalyst enhance the process's eco-friendliness, making it an appealing option for large-scale pharmaceutical synthesis.