Efficient synthesis of 1,4-Dihydropyridine derivatives using Silicomolybdic acid: Exploring catalytic potential and biological relevance.

Heterocyclic frameworks play a central role in modern medicinal chemistry, constituting the core of numerous therapeutic agents with diverse biological activities. In current scenario, 1,4-Dihydropyridines (1,4-DHPs) constitute an important class of nitrogen-containing heterocycles with diverse pharmacological activities, including antihypertensive, antioxidant, anti-inflammatory, anticancer, and neuroprotective properties. However, many existing synthetic methods for 1,4-DHPs generally suffer from harsh reaction conditions, long reaction times, too many considerable parameters, restricted reusability and limited reusability. In this study, we report a practical, efficient, and operationally simple protocol for the one-pot multicomponent synthesis of 1,4-DHP derivatives using Silicomolybdic acid (SMA), a robust heteropoly acid catalyst known for its strong Brønsted acidity, redox properties and excellent recyclability. SMA effectively promotes the condensation of aromatic aldehydes, dimedone, ethyl acetoacetate (EAA), and ammonium acetate (NH4OAc) under mild conditions, enabling the synthesis of 1,4-DHPs with high purity and improved yields (85–97%) without the need for column chromatography. Optimization studies highlight SMA's superior catalytic behaviour, while its operational stability is demonstrated by consistent performance over at least five recycling cycles. A gram-scale experiment further demonstrates the scalability of the method, supporting its potential utility in preparative synthesis.