MFA zeotype catalyst: a greener approach for the synthesis of INH azomethine scaffolds

Herein, we are reporting the green and efficient synthesis of some pharmacologically important azomethine derivatives of isoniazide (INH) using Modified Fly Ash (MFA) as an excellent zeotic solid acid catalyst. The catalyst, by virtue of its terminal hydroxyl groups, forms hydrogen bonds with carbonyl compounds, which activates these reactants for condensation. The MFA was assessed for various aspects like crystallinity, porosity, elemental composition, linkages and also for its stability, which were confirmed with the help of some physical spectral analyses like XRD, BET, EDS, FTIR and TGA. An effective MFA synthesis was achieved by the calcination of an aqueous mixture of fly ash with ferric chloride, successfully incorporating the iron to generate a slightly acidic crystalline zeotic material, which served as an energy efficient catalyst by allowing access to the reaction at room temperature.