Home Poly(ethylene)glycol/AlCl3 as a new and efficient system for multicomponent Biginelli-type synthesis of pyrimidinone derivatives
Article Open Access

Poly(ethylene)glycol/AlCl3 as a new and efficient system for multicomponent Biginelli-type synthesis of pyrimidinone derivatives

  • Ali Amoozadeh , Salman Rahmani EMAIL logo and Firouzeh Nemati
Published/Copyright: March 26, 2013
Download Article (PDF)
Heterocyclic Communications
From the journal Heterocyclic Communications Volume 19 Issue 1

Abstract

Biginelli condensation of aldehydes, cyclopentanone and urea or thiourea in poly(ethylene)glycol 400, at 45°C in the presence of aluminum chloride as a highly efficient catalyst has been developed. The reaction is very fast, clean and environmentally benign for the synthesis of a vast variety of pyrimidinone derivatives.

Keywords: aluminum chloride; Biginelli condensation; poly(ethylene)glycol; pyrimidinone

Introduction

Multicomponent reactions (MCRs) are important transformations in organic and medicinal chemistry [1–4]. These types of condensation reactions provide a fast and easy access to a variety of polyheterocyclic compounds of therapeutic and pharmacological properties [5–7]. The Biginelli reaction is a three-component reaction which is involves an α-ketoester, an urea or thiourea, and an aldehyde to produce 3,4-dihydro-2(1H)-pyrimidinones [6]. Many of such compounds show interesting bioactivity [8–11] or are used as substrates to prepare heterocyclic products with pharmacological properties [12]. These reasons have motivated researchers to extend the scope of the method to other 1,3-dicarbonyl compounds such as β-diamides [13], cyclic diketones [14] and β-ketolactones [15]. Another modification has been focused on the use of different acidic catalysts, mostly in the presence of a polar solvent. Formerly, the Biginelli reaction suffered from the need of harsh conditions to afford acceptable yields. Recently, the development of mild Lewis acid [8, 9, 10, 16] and heteropolyacid [17] catalysts has considerably improved the yield of the reaction. In the presence of such catalysts, the reaction is relatively facile, leading to high yields of dihydropyrimidinones. These catalysts include InCl3 [8], BiCl3 [10], phenylpyruvic acid [14], Al(NO3)3‧9H2O [18], H2SO4 [19], BF3‧Et2O/CuCl [20], LaCl3‧7H2O in the presence of concentrated HCl [21], CeCl3‧7H2O [22], heteropolyacids [23], Cu(OTf)2 [24], TMSCl [25], LiClO4 [26], LiBr [27], InBr3 [28], FeCl3‧6H2O/HCl [29], TMSI [30], Brønsted acidic ionic liquid [31], ionic liquid [32] and base catalyst [33]. They have been used with success in ethanol, acetic acid, tetrahydrofuran, acetonitrile or N,N-dimethylformamide.

Results and discussion

In continuation of our studies on developing inexpensive and environmentally benign methodologies for organic reactions especially with the use of poly(ethylene)glycol 400 (PEG 400) as a green and reusable solvent [34–40], we now report for the first time aluminum chloride catalyzed Biginelli condensation reaction of cyclopentanone with a vast variety of aldehydes with both urea or thiourea using PEG 400 as the reaction medium (Equation 1). The versatility of aluminum chloride and the environmentally benign nature of PEG encouraged us to couple them and study their utility for pyrimidinone synthesis reaction. To the best of our knowledge, there are no literature reports on Biginelli condensation under these conditions.

At the beginning, we studied the reaction under solvent-free conditions in the presence of 0–0.4 mmol AlCl3 as catalyst. TLC analysis showed that the best quantity of AlCl3 is 0.3 mmol. Owing to low yields (0–46%), we decided to perform the reaction in a solvent to potentially increase the obtained yields. We tested CHCl3, CH2Cl2, Et2O, CH3CN, EtOH, THF and PEG as solvents for Biginelli condensations of cyclopentanone, benzaldehyde and urea in the presence of 0.3 mmol AlCl3 as catalyst. The results showed that this reaction is highly solvent-dependent. It does not work at all in ethanol. It seems that alcohols with low molecular weight are not suitable choices as solvents for the reactions catalyzed by AlCl3 because they can react readily with Lewis acid. In addition, the reaction does not work well in chloroform, dichloromethane, diethyl ether or tetrahydrofuran (yields in the range of 25–65%). Fortunately, in the case of PEG 400 as solvent, the yield is excellent (91%).

The Biginelli condensation of cyclopentanone, benzaldehyde and urea in PEG 400 as solvent in the presence of different amounts of AlCl3 as catalyst (0.0–0.4 mmol) at room temperature was performed. Similarly to the solvent-free conditions, the amount of 0.3 mmol of AlCl3 as catalyst is optimal to give yield of 91%. The effect of temperature on the Biginelli condensation of cyclopentanone, benzaldehyde and urea in presence of 0.3 mmol AlCl3 in PEG 400 as solvent was studied. Reaction was performed at 45°C, 60°C and 80°C. With increases in the temperature up to 45°C, the yield was also increased up to yield 94%. However, a further rise in temperature to 80°C caused a decrease in yield, from 89% at 60°C to 84% at 80°C. In summary, the optimal temperature for this reaction is 45°C.

The reaction works easily for a vast variety of aldehydes with both electron-donating and electron-withdrawing groups with both urea and thiourea to give corresponding pyrimidinone derivatives in good to excellent yields. The new compounds characterized by FT-IR, 1H NMR, 13C NMR and CHN analysis (Experimental section). However, it should be noted that the reaction time for aldehydes with electron-withdrawing groups is considerably longer (4b–4e vs. 4f, 4g). High yields for the reaction of electron-rich aldehydes have been noted [41]. In their proposed mechanism, Zhang et al. [41] have suggested aldol condensation between cyclopentanone and aldehyde to produce corresponding α,α′-bis(substituted benzylidene)cyclopentanone 5. Then this intermediate product would react with urea or thiourea to produce desired pyrimidinone 4a,h [41] (Equation 2). Concerning this proposed mechanism, we expected that compound 5 would also undergo reaction with urea or thiourea under our conditions to produce pyrimidinone 4. However, compound 4 was not found in the reaction mixture, which suggests that the mechanism of this transformation requires additional studies.

Conclusion

Efficient conditions for the synthesis of pyrimidinone derivatives using Biginelli reaction by condensation of cyclopentanone with different aldehydes and urea and/or thiourea in the presence of AlCl3, in PEG as a green and reusable solvent are reported. This protocol is a low cost procedure that is also user and environmentally friendly.

Experimental

General

Chemicals were purchased from Merck and Aldrich chemical companies. Thin layer chromatography (TLC) on commercial aluminum backed plates of silica gel 60 F254 was used to monitor the progress of reactions. Melting points were recorded on a Thermo Scientific 9100 apparatus. The FT-IR spectra were taken on a Perkin-Elmer, model 783, spectrophotometer in KBr pellets. The 1H NMR spectra (300 MHz) and 13C NMR spectra (75 MHz) were recorded in DMSO-d6 on a Bruker AMX-300 spectrometer. Elemental analyses were performed on a Perkin-Elmer CHN analyzer, 2400 series II.

General procedure for preparation of pyrimidinones 4a–n

A mixture of aldehyde (1 mmol), ketone (1 mmol), urea or thiourea (1.2 mmol) and AlCl3 (0.3 mmol) in PEG (2 mL) was stirred at 45°C for a period of time indicated below. After completion of the reaction, as monitored by TLC, distilled water (4 mL) was added. The solid precipitate was filtered and washed with absolute ethanol or ethyl acetate (3 mL) and acetone (2 mL) and dried in air.

As an alternative work-up procedure, the reaction mixture was cooled in a dry ice-acetone bath to precipitate the PEG 400 and organic products were extracted with ether. The ether layer was washed with water (2 mL) and dried over MgSO4. The organic solvent was removed under reduced pressure to give the crude product 4a–n. The product was crystallized from ethanol.

(7E)-7-Benzylidene-3,4,6,7-tetrahydro-4-phenyl-1H-cyclopenta[d]pyrimidin-2(5H)-one (4a)

Yellow solid; yield 94%; mp 238–240°C; (lit mp 236–239°C [25]); reaction time 2.5 h.

(7E)-7-(2-Chlorobenzylidene)-4-(2-chlorophenyl)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-one (4b)

Yellow solid; yield 86%; mp 228–231°C; (lit mp 232–234°C [25]); reaction time 5.5 h.

(7E)-7-(3-Nitrobenzylidene)-3,4,6,7-tetrahydro-4-(3-nitrophenyl)-1H-cyclopenta[d]pyrimidin-2(5H)-one (4c)

Brown solid; yield 84%; mp 233–235°C ; (lit mp 235–239°C [25]); reaction time 4.2 h.

(7E)-7-(4-Chlorobenzylidene)-4-(4-chlorophenyl)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-one (4d)

Yellow-green solid; yield 89%; mp 250–253°C; (lit mp 252–255°C [25]); reaction time 4.5 h.

(7E)-7-(4-Bromobenzylidene)-4-(4-bromophenyl)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-one (4e)

Yellow solid; yield 96%; mp 219–222°C; (lit mp 221–222°C [41]); reaction time 3.5 h.

(7E)-7-(4-Methylbenzylidene)-4-(4-methylphenyl)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-one (4f)

Dark yellow solid; yield 96%; mp 241–243°C; (lit mp 238–241°C [25]); reaction time 2.2 h.

(7E)-7-(4-Methoxybenzylidene)-4-(4-methoxyphenyl)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-one (4g)

Yellow solid; yield 95%; mp 254–257°C; (lit mp 250–252°C [25]); reaction time 2 h.

(7E)-7-Benzylidene-3,4,6,7-tetrahydro-4-phenyl-1H-cyclopenta[d]pyrimidine-2(5H)-thione (4h)

Pink solid; yield 96%; mp 218–221°C; (lit mp 219–223°C [25]); reaction time 1 h.

(7E)-7-(4-Chlorobenzylidene)-4-(4-chlorophenyl)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidine-2(5H)-thione (4i)

Light red solid; yield 90%; mp 223–225°C; (lit mp 226–228°C [25]); reaction time 2.3 h.

(7E)-7-(3-Nitrobenzylidene)-3,4,6,7-tetrahydro-4-(3-nitrophenyl)-1H-cyclopenta[d]pyrimidine-2(5H)-thione (4j)

Dark brown solid; yield 92%; mp 309–312°C; (lit mp 313–317°C [25]); reaction time 3 h.

(7E)-7-(4-Nitrobenzylidene)-3,4,6,7-tetrahydro-4-(4-nitrophenyl)-1H-cyclopenta[d]pyrimidine-2(5H)-thione (4k)

Brown solid; yield 79%; mp 199–202°C; (lit mp 203–207°C [25]); reaction time 3.25 h.

7-(4-Methoxybenzylidene)-4-(4-methoxyphenyl)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-thione (4l)

Light yellow solid; yield 93%; mp 218–220°C; reaction time 0.75 h; IR: ν 3851, 3566, 1541, 1508, 1245, 1174, 1026 cm-1; 1H NMR: δ 9.98 (1H, s, NH), 8.90 (1H, s, HC=), 6.90–7.29 (8H, m, CH), 6.84 (1H, s, NH), 5.11 (1 H, s, CH), 3.73–3.74 (6H, OMe), 2.77 (2H, s, CH2), 2.41–2.42 (1H, d, CH2), 2.03–2.07 (1H, d, CH2); 13C NMR: δ 173.9, 158.9, 157.7, 135.5, 134.5, 133.9, 130.3, 129.3, 127.9, 120.1, 117.2, 114.0, 57.3, 28.4, 27.8. Anal. Calcd for C22H22N2O2S: C, 69.81; H, 5.86; N, 7.40. Found: C, 69.92; H, 5.70; N, 7.61.

4-(Naphthalen-2-yl)-7-(naphthalen-2-ylmethylene)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin-2(5H)-thione (4m)

Red solid; yield 82%; mp 238–240°C; reaction time 0.5 h; IR: ν 3392, 3322, 1544, 1483, 1191, 820, 746 cm-1; 1H NMR: δ 10.22 (1H, s, NH), 9.13 (1H, s, HC=), 7.41–7.99 (14H, m, CH), 7.14 (1H, s, NH), 5.41 (1H, s, CH), 2.84–3.02 (2H, m, CH2), 2.44–2.52 (1H, m, CH2), 2.05–2.12 (1H, m, CH2); 13C NMR: δ 174.4, 139.6, 138.6, 135.3, 134.2, 133.2, 132.8, 132.6, 131.5, 128.6, 127.9, 127.6, 127.4, 126.7, 126.5, 126.2, 124.8, 125.2, 121.3, 117.9, 58.2, 28.5, 28.1. Anal. Calcd for C28H22N2S: C, 80.35; H, 5.30; N, 6.69. Found: C, 80.48; H, 5.42; N, 6.79.

7-(4-Bromobenzylidine)-4-(4-bromophenyl)-3,4,6,7-tetrahydro-1H-cyclopenta[d]pyrimidin2(5H)-thione (4n)

Yellow solid; yield 86%; mp 226–228°C; reaction time 1.5 h; IR: ν 3240, 2920, 1672, 1558, 1489, 1186, 1090, 872 cm-1; 1H NMR: δ 10.12 (1H, s, NH), 9.03 (1H, s, HC=), 7.07–7.59 (8H, m, CH), 6.90 (1H, s, NH), 5.23 (1H, s, CH), 2.72–2.88 (2H, m, CH2), 2.39–2.53 (1H, m, CH2), 2.02–2.09 (1H, m, CH2); 13C NMR: δ 174.4, 141.1, 138.7, 136.5, 134.0, 132.4, 130.5, 129.6, 128.8, 128.6, 121.3, 116.7, 69.8, 57.1, 28.3, 27.9. Anal. Calcd for C20H16Br2N2S: C, 50.44; H, 3.39; N, 5.88. Found: C, 50.31; H, 3.47; N, 5.64.

Corresponding author: Salman Rahmani, Faculty of Chemistry, Department of Organic Chemistry, Semnan University, 35195-363, Semnan, Iran

We thank the Department of Chemistry of Semnan University for supporting this work.

References

[1] Kappe, C. O. A reexamination of the mechanism of the Biginelli dihydropyrimidine synthesis. Support for an N-acyliminium ion intermediate. J. Org. Chem. 1997, 62, 7201–7204.Search in Google Scholar

[2] Kappe, C. O.; Fabian, W. M. F.; Semones, M. A. Conformational analysis of 4-aryl-dihydropyrimidine calcium channel modulators. A comparison of ab initio, semiempirical and X-ray crystallographic studies. Tetrahedron 1997, 53, 2803–2816.Search in Google Scholar

[3] Domling, A.; Ugi, I. Multicomponent reactions with isocyanides. Angew. Chem. Int. Ed. 2000, 39, 3169–3210.Search in Google Scholar

[4] Simon, C.; Constantieux, T.; Rodriguez, J. Utilisation of 1,3-dicarbonyl derivatives in multicomponent reactions. Eur. J. Org. Chem. 2004, 24, 4957–4980.Search in Google Scholar

[5] Kappe, C. O. 100 years of the Biginelli dihydropyrimidine synthesis. Tetrahedron 1993, 49, 6937–6963.10.1016/S0040-4020(01)87971-0Search in Google Scholar

[6] Rovnyak, G. C.; Kimball, S. D.; Beyer, B.; Cucinotta, G.; Dimarco, J. D.; Gougoutas, J.; Hedberg, A.; Malley, M.; Mc Carthy, J. P.; Zhang, R. A.; Moreland, S. Calcium entry blockers and activators: conformational and structural determinants of dihydropyrimidine calcium channel modulators. J. Med. Chem. 1995, 38, 119–129.Search in Google Scholar

[7] Atwal, K. S.; Rovnyak, G. C.; Kimball, S. D.; Floyd, D. M.; Moreland, S.; Swanson, B. N.; Gougoutas, J. Z.; Schwartz, J.; Smillie, K. M.; Malley, M. F. Dihydropyrimidine calcium channel blockers. II. 3-Substituted-4-aryl-1,4-dihydro-6-methyl-5-pyrimidinecarboxylic acid esters as potent mimics of dihydropyridines. J. Med. Chem. 1990, 33, 2629–2635.Search in Google Scholar

[8] Ranu, B. C.; Hajra, A.; Jana, U. Indium(III) chloride-catalyzed one-pot synthesis of dihydropyrimidinones by a three-component coupling of 1,3-dicarbonyl compounds, aldehydes and urea: an improved procedure for the Biginelli reaction. J. Org. Chem. 2000, 65, 6270–6272.Search in Google Scholar

[9] Ma, Y.; Qian, C. T.; Wang, L. M.; Yang, M. Lanthanide triflate catalyzed Biginelli reaction. One-pot synthesis of dihydropyrimidinones under solvent-free conditions. J. Org. Chem. 2000, 65, 3864–3868.Search in Google Scholar

[10] Ramalinga, K.; Vijayalakshmi, P.; Kaimal, T. N. B. Bismuth(III)-catalyzed synthesis of dihydropyrimidinones: improved protocol conditions for the Biginelli reaction. Synlett 2001, 6, 863–865.Search in Google Scholar

[11] Atwal, K. S.; Swanson, B. N.; Unger, S. E.; Floyd, D. M.; Moreland, S.; Hedberg, A.; Oreilly, B. C. Dihydropyrimidine calcium channel blockers. 3. 3-Carbamoyl-4-aryl-1,2,3,4-tetrahydro-6-methyl-5-pyrimidinecarboxylic acid esters as orally effective antihypertensive agents. J. Med. Chem. 1991, 34, 806–811.Search in Google Scholar

[12] Kappe, C. O. Biologically active dihydropyrimidones of the Biginelli-type: a literature survey. Eur. J. Med. Chem. 2000, 35, 1043–1052.Search in Google Scholar

[13] Mokrosz, J. L.; Paluchowska, M. H.; Szneler, E.; Drozdz, B. The effect of aryl substituents in some spiro[2-oxo-4,6-bis (aryl)hexahydropyrimidine-5,52-barbituric acids]. Arch. Pharm. 1989, 322, 231–235.Search in Google Scholar

[14] Abelman, M. M.; Smith, S. C.; James, D. R. Cyclic ketones and substituted α-keto acids as alternative substrates for novel Biginelli-like scaffold syntheses. Tetrahedron Lett. 2003, 44, 4559–4562.Search in Google Scholar

[15] Byk, G.; Gottlieb, H. E.; Herscovici, J.; Mirkin, F. New regioselective multicomponent reaction: one pot synthesis of spiro heterobicyclic aliphatic rings. J. Comb. Chem. 2000, 2, 732–735.Search in Google Scholar

[16] Bigi, F.; Carloni, S.; Frullanti, B.; Maggi, R.; Sartori, G. A revision of the Biginelli reaction under solid acid catalysis. Solvent-free synthesis of dihydropyrimidines over montmorillonite KSF. Tetrahedron Lett. 1999, 40, 3465–3468.Search in Google Scholar

[17] Yadav, J. S.; Reddy, B. V. S.; Sridhar, P.; Reddy, J. S. S.; Nagaiah, K.; Lingaiah, N.; Saiprasad, P. S. Green protocol for the Biginelli three-component reaction: Ag3PW12O40 as a novel, water-tolerant heteropolyacid for the synthesis of 3,4-dihydropyrimidinones. Eur. J. Org. Chem. 2004, 3, 552–557.Search in Google Scholar

[18] Kolvari, E.; Zolfigol, M. A.; Mirzaeean, M. Aluminium nitrate nonahydrate (Al(NO3)3 · 9H2O): an efficient oxidant catalyst for the one-pot synthesis of Biginelli compounds from benzyl alcohols. Helv. Chim. Acta 2012, 95, 115–119.Search in Google Scholar

[19] Folkers, P. J. M.; Folmer, R. H. A.; Konings, R. N. H.; Hilbers, C. W. Overcoming the ambiguity problem encountered in the analysis of nuclear Overhauser magnetic resonance spectra of symmetric dimer proteins. J. Am. Chem. Soc. 1993, 115, 3798–3799.Search in Google Scholar

[20] Hu, E. H.; Sidler, D. R.; Dolling, U. H. Unprecedented catalytic three component one-pot condensation reaction: an efficient synthesis of 5-alkoxycarbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones. J. Org. Chem. 1998, 63, 3454–3457.Search in Google Scholar

[21] Lu, J.; Bai, Y. J.; Wang, Z. J.; Yang, B. Q.; Ma, H. R. One-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones using lanthanum chloride as a catalyst. Tetrahedron Lett. 2000, 41, 9075–9078.Search in Google Scholar

[22] Bose, D. S.; Fatima, L.; Mereyala, H. B. Green chemistry approaches to the synthesis of 5-alkoxycarbonyl-4-aryl-3,4-dihydropyrimidin-2(1H)-ones by a three-component coupling of one-pot condensation reaction: comparison of ethanol, water and solvent-free conditions. J. Org. Chem. 2002, 68, 587–590.Search in Google Scholar

[23] Rafiee, E.; Jafari, H. A practical and green approach towards synthesis of dihydropyrimidinones: using heteropolyacids as efficient catalysts. Bioorg. Med. Chem. Lett. 2006, 16, 2463–2466.Search in Google Scholar

[24] Paraskar, A. S.; Dewkar, G. K.; Sudalai, A. Cu(OTf)2: a reusable catalyst for high-yield synthesis of 3,4-dihydropyrimidin-2(1H)-ones. Tetrahedron Lett. 2003, 44, 3305–3308.Search in Google Scholar

[25] Zhu, Y. L.; Huang, S. L.; Pan, Y. J. Highly chemoselective multicomponent Biginelli-type condensations of cycloalkanones, urea or thiourea and aldehydes. Eur. J. Org. Chem. 2005, 11, 2354–2367.Search in Google Scholar

[26] Yadav, J. S.; Reddy, B. V. S.; Srinivas, R.; Venugopal, C.; Ramalingam, T. LiClO4-catalyzed one-pot synthesis of dihydropyrimidinones: an improved protocol for Biginelli reaction. Synthesis 2001, 9, 1341–1345.Search in Google Scholar

[27] Maiti, G.; Kundu, P.; Guin, C. One-pot synthesis of dihydropyrimidinones catalysed by lithium bromide: an improved procedure for the Biginelli reaction. Tetrahedron Lett. 2003, 44, 2757–2758.Search in Google Scholar

[28] Fu, N. Y.; Yuan, Y. F.; Cao, Z.; Wang, S. W.; Wang, J. T.; Peppe, C. Indium(III) bromide-catalyzed preparation of dihydropyrimidinones: improved protocol conditions for the Biginelli reaction. Tetrahedron 2002, 58, 4801–4807.Search in Google Scholar

[29] Lu, J.; Ma, H. R. Iron(III)-catalyzed synthesis of dihydropyrimidinones. Improved conditions for the Biginelli reaction. Synlett 2000, 1, 63–64.10.1055/s-2000-6469Search in Google Scholar

[30] Sabitha, G.; Reddy, G.; Reddy, C. S.; Yadav, J. S. One-pot synthesis of dihydropyrimidinones using iodotrimethylsilane. Facile and new improved protocol for the Biginelli reaction at room temperature. Synlett 2003, 6, 858–860.Search in Google Scholar

[31] Rahman, M.; Majee, A.; Hajra, A. Microwave-assisted Brønsted acidic ionic liquid-promoted one-pot synthesis of heterobicyclic dihydropyrimidinones by a three-component coupling of cyclopentanone, aldehydes, and urea. J. Heterocycl. Chem. 2010, 47, 1230–1233.Search in Google Scholar

[32] Banothu, J.; Somarapu, L.; Rajitha Bavanthu, V. One-pot synthesis of fused 3,4-dihydropyrimidin-2(1H)-ones and thiones using a novel ionic liquid as an efficient and reusable catalyst: improved protocol conditions for the Biginelli-like scaffolds. Heterocycl. Commun. 2012, 18, 93–97.Search in Google Scholar

[33] Zhong-Xu, D.; Chen, H.; Liu, M.; Ding, M. Efficient synthesis of thieno[2,3-d]pyrimidin-4(3H)-ones by a sequential aza-Wittig reaction/base catalyzed cyclization. Heterocycl. Commun. 2011, 17, 197–201.Search in Google Scholar

[34] Bigdeli, M. A.; Dostmohammadi, H.; Mahdavinia, G. H.; Nemati, F. A simple and efficient procedure for the synthesis of benzimidazoles using trichloroisocyanuric acid (TCCA) as the oxidant. J. Heterocycl. Chem. 2008, 45, 1203–1205.Search in Google Scholar

[35] Bigdeli, M. A.; Heravi, M. M.; Nemati, F. Mild and selective nitration of phenols by zeofen. Synth. Commun. 2007, 37, 2225–2230.Search in Google Scholar

[36] Bigdeli, M. A.; Nemati, F.; Mahdavinia, G. H. HClO4–SiO2 catalyzed stereoselective synthesis of β-amino ketones via a direct Mannich-type reaction. Tetrahedron Lett. 2007, 48, 6801–6804.Search in Google Scholar

[37] Amoozadeh, A.; Nemati, F. A clean, mild and selective oxidation of sulfides to sulfoxides using NaClO/H2SO4 in aqueous media. Phosphorus Sulfur Silicon Relat. Elem. 2009, 184, 2569–2575.Search in Google Scholar

[38] Amoozadeh, A.; Nemati, F. Poly(ethylene)glycol as a green and reusable solvent in the oxidation of sulfides to sulfoxides using NaClO. Phosphorus Sulfur Silicon Relat. Elem. 2010, 185, 1381–1385.Search in Google Scholar

[39] Amoozadeh, A.; Nemati, F. Solid silica-based sulphonic acid as an efficient green catalyst for the selective oxidation of sulphides to sulphoxides using NaClO in aqueous media. S. Afr. J. Chem. 2009, 62, 44–46.Search in Google Scholar

[40] Amoozadeh, A.; Rahmani, S.; Nemati, F. Poly(ethylene)glycol/AlCl3 as a green and reusable system in the synthesis of α,α′-bis(substituted-benzylidene)cycloalkanones. S. Afr. J. Chem. 2010, 63, 72–74.Search in Google Scholar

[41] Zhang, H. H.; Zhou, Z. Q.; Yao, Z. G.; Xu, F.; Shen, Q. Efficient synthesis of pyrimidinone derivatives by ytterbium chloride catalyzed Biginelli-type reaction under solvent-free conditions. Tetrahedron Lett. 2009, 50, 1622–1624.Search in Google Scholar

Received: 2012-10-20
Accepted: 2012-12-8
Published Online: 2013-03-26
Published in Print: 2013-03-01

©2013 by Walter de Gruyter Berlin Boston

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Articles in the same Issue

  1. Masthead
  2. Masthead
  3. Reviews
  4. Synthesis and applications of benzothiazole containing cyanine dyes
  5. Synthesis and chemistry of structurally unique hexasubstituted pyrazolines
  6. Research Articles
  7. Synthesis and characterization of heteroarylthio derivatives of 5,17-di-tert-butyl-11,23-diamido-25, 27-diprotected calix[4]arene
  8. New heterocyclic chalcones. Part 6. Synthesis and cytotoxic activities of 5- or 6-(3-aryl- 2-propenoyl)-2(3H)-benzoxazolones
  9. Novel benzofuran derivatives: synthesis and antitumor activity
  10. Synthesis, characterization and in vitro antimicrobial assessment of some novel 4H-1, 4-benzothiazines and their sulfone derivatives
  11. Efficient synthesis, X-ray diffraction study and antimicrobial activity of some novel thiazolidin-4-ones and perhydro-1,3-thiazin-4-ones
  12. A simple and efficient synthesis of novel naphthyridine-1-H-pyrazole-4-carboxylic acid esters/carbaldehydes using Vilsmeier-Haack reagent
  13. Melamine-formaldehyde resin supported H+-catalyzed three-component synthesis of 1,8-dioxo-decahydroacridine derivatives in water and under solvent-free conditions
  14. A simple and efficient procedure for synthesis of symmetrical bis(4-amino-4H-1,2,4-triazole-5-thiols)
  15. Poly(ethylene)glycol/AlCl3 as a new and efficient system for multicomponent Biginelli-type synthesis of pyrimidinone derivatives
  16. Synthesis, crystal structure, and bioactivity of N-dichloroacetyl diazabicyclo compounds
https://doi.org/10.1515/hc-2012-0157
Keywords for this article
aluminum chloride; Biginelli condensation; poly(ethylene)glycol; pyrimidinone
Creative Commons
BY-NC-ND 3.0

Articles in the same Issue

  1. Masthead
  2. Masthead
  3. Reviews
  4. Synthesis and applications of benzothiazole containing cyanine dyes
  5. Synthesis and chemistry of structurally unique hexasubstituted pyrazolines
  6. Research Articles
  7. Synthesis and characterization of heteroarylthio derivatives of 5,17-di-tert-butyl-11,23-diamido-25, 27-diprotected calix[4]arene
  8. New heterocyclic chalcones. Part 6. Synthesis and cytotoxic activities of 5- or 6-(3-aryl- 2-propenoyl)-2(3H)-benzoxazolones
  9. Novel benzofuran derivatives: synthesis and antitumor activity
  10. Synthesis, characterization and in vitro antimicrobial assessment of some novel 4H-1, 4-benzothiazines and their sulfone derivatives
  11. Efficient synthesis, X-ray diffraction study and antimicrobial activity of some novel thiazolidin-4-ones and perhydro-1,3-thiazin-4-ones
  12. A simple and efficient synthesis of novel naphthyridine-1-H-pyrazole-4-carboxylic acid esters/carbaldehydes using Vilsmeier-Haack reagent
  13. Melamine-formaldehyde resin supported H+-catalyzed three-component synthesis of 1,8-dioxo-decahydroacridine derivatives in water and under solvent-free conditions
  14. A simple and efficient procedure for synthesis of symmetrical bis(4-amino-4H-1,2,4-triazole-5-thiols)
  15. Poly(ethylene)glycol/AlCl3 as a new and efficient system for multicomponent Biginelli-type synthesis of pyrimidinone derivatives
  16. Synthesis, crystal structure, and bioactivity of N-dichloroacetyl diazabicyclo compounds
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 29.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/hc-2012-0157/html
Scroll to top button