Nahid Musivand - Department of Chemistry, Iran University of Science & Technology, Tehran ۱۶۸۴۶۱۳۱۱۴, Iran
Mohammad G. Dekamin - Department of Chemistry, Iran University of Science & Technology, Tehran ۱۶۸۴۶۱۳۱۱۴, Iran
Ghasem Rezanejade Bardajee - Department of Chemistry, Payame Noor University, P.O. BOX, ۱۹۳۹۵-۳۶۹۷, Tehran, Iran

The disclosure of Biginelli reaction by the chemist Pietro Biginelli, functionalized 3,4-dihydropyrimidin-2(1H)-ones/thiones (DHPMs) have emerged as prototypes for the design of compounds with a broad variety of biological activities such as antiviral, antitumor, cardiovascular antibacterial, anti-inflammatory and antioxidant properties.1 A simple, green, nontoxic and efficient method was found to be for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and -thiones through one-pot three-component reaction of ethyl acetoacetate (methyl acetoacetate), an aromatic aldehyde and urea or thiourea under solvent-free conditions using Kappa Carrageenan as an efficient, heterogeneous, economical, biocompatible and green catalyst.2, 3 Compared with classical Biginelli reaction conditions, the new method has several advantages such as good yields, relatively short reaction times, mild reaction conditions and a the nontoxic catalyst with a very easy work up.4