Abstract

REVIEW BIGINELLI REACTIONS: REAGENT SUPPORT BASED APPROACHES

Rajendra Patil, Jagdish Chavan and Anil Beldar*

ABSTRACT

Multicomponent reactions (MCRs) leading to synthesis of heterocycles which are pharmaceutically important have underwent consistent advancements. One of such MCR is Biginelli reaction; its three component reaction involves one pot cyclocondensation of aromatic aldehyde, β-keto ester and urea or thiourea catalyzed by strong acid to yield substituted 3,4-dihydropyrimidine-(1H)-2-one (DHPM). The original Biginelli reaction has low yields and needs to perform purification steps to isolate the desire products. However such drawbacks are overcome by employing different catalysts, solid phase synthetic approaches or by multistep synthesis. From literature, it comes to know that polymer supported catalysis have improved the yields and help to reduce the efforts for purification of products. Another efficient approach for Biginelli reaction uses multistep synthesis using polymer assistance which have improved yields considerably and provided products with high purity where no chromatographic techniques are needed. Polymer mediated synthesis of Biginelli products is also reported.

Keywords: Biginelli reactions; DHPM; MCR; Cyclocondensation.