%0 Journal Article
%T Microwave-Assisted Synthesis and Biological Evaluation of Dihydropyrimidinone Derivatives as Anti-Inflammatory, Antibacterial, and Antifungal Agents
%A Anjna Bhatewara
%A Srinivasa Rao Jetti
%A Tanuja Kadre
%A Pradeep Paliwal
%A Shubha Jain
%J International Journal of Medicinal Chemistry
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/197612
%X A simple protocol for the efficient preparation of aryl and heteroaryl substituted dihydropyrimidinone has been achieved via initial Knoevenagel, subsequent addition, and final cyclization of aldehyde, ethylcyanoacetate, and guanidine nitrate in the presence of piperidine as a catalyst in solvent-free under microwave irradiation. The synthesized compounds showed a good anti-inflammatory, antibacterial, and antifungal activity. 1. Introduction Pyrimidinones have been paid increasing attention, due to their various therapeutic and pharmacological properties, such as antiviral, antibacterial, antihypertensive, and antitumor effects [1]. More recently, they emerged as integral backbones of several calcium blockers, antihypertensive agents, ¦Á-1a-antagonists, and neuropeptide Y (NPY) antagonists [2]. Pyrimidinone derivatives are found as core units in many marine alkaloids (batzelladine and carambine), which have been found to be potent to HIV-gp-120 CD4 inhibitors [3]. Due to the remarkable biological utilization, the pyrimidinones attract many researchers as well as academicians. Recently, several methods improved the procedure using phosphorus pentoxide-methanesulfonic acid [4], potassium ter-butoxide (t-BuOK) [5], ammonium dihydrogen phosphate [6], silica-gel [7], mesoporous molecular sieve MCM-41 [8], cyanuric chloride [9], nano-BF3¡¤SiO2 [10], silica gel-supported polyphosphoric Acid [11], zirconium(IV) chloride [12], and indium(III) bromide [13] as catalysts. However, some of these one-pot procedures generally require strong protic or Lewis acids, prolonged reaction times, and high temperature. Consequently, there is a scope for further modification towards mild reaction condition, increased variation of the substituents, and improved yields. Microwave promoted solvent-free reactions [14] are well known as environmentally benign methods that also usually provide improved selectivity, enhanced reaction rates, cleaner products, and manipulative simplicity [15]. However, these procedures are practically limited as the solvents in microwave oven at elevated temperatures create high pressures, which may cause explosion. To circumvent these problems, there is a need for the development of newer methods which proceed under mild and solvent free condition. Nowadays solvent-free reactions gained much importance in organic synthesis because of the high yields and shorter reaction times. Earlier reported procedures for the synthesis of pyrimidine derivatives typically involved longer reaction time and fewer yields [16]. In the present communication, we would like
%U http://www.hindawi.com/journals/ijmc/2013/197612/