Use of Piperidine and Pyrrolidine in Knoevenagel Condensation

Abstract

Glitazones are an important class of drugs used specially in the treatment of diabetes mellitus type II. Pharmaceuticals intermediates which originates glitazones can be formed by the reaction of a carbonyl with an activated methylene, though Knoevenagel condesantion using a weak base as catalyst. In this study, tiazolidine-2,4-dione (TZD) was reacted with p-metoxybenzaldehyde and p-nitrobenzaldehyde, using piperidine and pyrrolidine as catalysts. The influence of the substituent was evident, 4-metoxybenzaldehyde showed the highest value of TZD conversion. Pyrrolidine showed higher value of TZD conversion than piperidine for both aldehydes, reaching a conversion of 100% to 4-methoxybenzaldehyde with lower amount of pyrrolidine corresponding to 62.5% of piperidine.