Fe+3-montmorillonite K10: As an effective and reusable catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and –thiones

L Z Fekri,M Nikpassand,M Movaghari

doi:10.4314/bcse.v31i2.12

Abstract

In this study, a novel, clean, convenient, appropriate and environmentally benign route to dihydropyrimidinone and thione derivatives has been developed using the reaction between various benzaldehydes, urea or thiourea, and ethyl acetoacetate in the presence of Fe +3 -montmorillonite K10 under grind condition. The present methodology has several advantages such as simple work-up, solvent-free conditions, environmental friendliness and shorter reaction time along with high yields. Several aromatic aldehydes carrying either electron-releasing or electron-withdrawing substituents in the ortho and para positions were tested in this reaction. Another important feature of this procedure is the survival of a variety of functional groups under the reaction conditions. All of synthesized compounds were characterized by IR, 1 HNMR, 13 CNMR and elemental analyses. KEY WORDS : Grinding, K10, Urea, Thiourea, Ethyl acetoacetate, Biginelli reaction Bull. Chem. Soc. Ethiop. 2017 , 31(2), 313-321. DOI: http://dx.doi.org/10.4314/bcse.v31i2.12

Highlights

In the past decade, dihydropyrimidinones (DHPMs) and their derivatives have attracted considerable interest because they exhibit promising activities such as calcium channel blockers, antihypertensive agents, and a-1a-antagonists and neuropeptide Y (NPY) antagonists [1]
In order to improve the efficiency of Biginelli reaction, a variety of catalysts have been reported which of them H4PMo11VO40 [9], Dowex50W [10], H3PW12O40/SiO2 [11], MgBr2 [12], polymer-supported 4-aminoformoyldiphenylammonium triflate [13], NaHSO4/SiO2 [14], FeCl3 [15], ZrCl4 [16], Cu(OTf)2 [17], Bi(OTf)3 [18], yutterbium triflate [19], 12-molbdophosphoric acid [20], natural HEU type zeolite [21], Sr(OTf)2 [22], covalently anchored sulfonic acid onto silica [23], ZrOCl28H2O [24], silica triflate [25], Fe(HSO4)3 [26], TCICA [27], PPh3 [28], CaF2 [29], [bmim]BF4-immobilized Cu(II) acetylacetonate [30], [bmim][FeCl4] [31], Fe+3- montmorillonite K10 [32], MCM-41 [33] and solvent free condition [34] are examples
To release the efficiency and generality of the reaction, various aldehydes were treated with ethyl acetoacetate and urea in this reaction condition in the presence of Fe+3-montmorillonite K10

Summary

Introduction

Dihydropyrimidinones (DHPMs) and their derivatives have attracted considerable interest because they exhibit promising activities such as calcium channel blockers, antihypertensive agents, and a-1a-antagonists and neuropeptide Y (NPY) antagonists [1]. In 1893, Petro Biginelli reported the first synthesis of 3,4-dihydropyrimidin-2(1H)-one (DHPM) by a very simple one-pot condensation reaction of an aromatic aldehyde, β-ketoesters and urea under strongly acidic conditions [8]. The development of simple, efficient, clean, high-yielding, and environmentally friendly approaches using new catalysts for the synthesis of these compounds is an important task for organic chemists.

Results

Conclusion