KNOEVENAGEL CONDENSATION CATALYZED BY SODIUM SILICATE
2037
EXPERIMENTAL
All reagents were purchased and used without further purification. Melting points
were determined by using XT-4 micro melting point apparatus. All reaction products were
known in the literature, and the NMR and IR spectra of the products were in agreement
with the published data.
General Procedure
The corresponding aldehyde (10 mmol) and the respective active methylene com-
pound (10 mmol) were mixed thoroughly and then 0.1 mmol of sodium silicate pentahydrate
was added. The reaction mixture was stirred for the time specified in Tables 1–3 at room
temperature. After completion of the reaction, the reaction mixture was treated with cold
5% aqueous ethanol (30 mL). The product was filtered and dried, and in general, no further
purification method was required. The authenticity of the known products was established
by comparing their melting points with those reported in the literature.
REFERENCES
1. Tanaka, K. F.; Chem. Rev. 2000, 100, 1025-1074.
2. (a) Jones, G.; Org. React. 1967, 15, 204-599; (b) Reeves, R. L., In The Chemistry of the Carbonyl
Group, S. Patai, Ed. (Interscience, New York, 1966), p. 593.
3. (a) Choudary, B. M.; Kantam, M. L.; Kavita, B.; Reddy, C. V.; Figueras, F.; Tetrahedron 2000, 56,
9357-9364; (b) Mitra, A. K.; De, A.; Karchaudhuri, N.; Synth. Commun. 1999, 29, 1532-2432;
(c) Wang, S. X.; Li, J. T.; Yang, W. Z.; Li, T. S.; Ultrason. Sonochem. 2002, 9, 237-239.
4. (a) Bigi, F.; Conforti, M. L.; Maggi, R.; Piccinni, A.; Sartori, G.; Green Chem. 2000, 3, 101-103;
(b) Hangarge, R. V.; Sonwane, S. A.; Jarikote, D. V.; Shingare, M. S.; Green Chem. 2002, 3,
266-268; (c) Hu, Y.; Chen, J.; Le, Z. G.; Zheng, Q. G.; Synth. Commun. 2005, 35, 739-744;
(d) Yamashita, K.; Tanaka, T.; Hayashi, M.; Tetrahedron 2005, 61, 7981-7985; (e) Lai, G.;
Peng, J.; Li, J.; Qiu, H.; Jiang, J.; Jiang, K.; Shen, Y.; Tetrahedron Lett. 2006, 47, 6951-6953;
(f) Trotzki, R.; Hoffmann, M. M.; Ondruschka, B.; Green Chem. 2008, 10, 873-878.
5. Vail, J. G., Soluble Silicates: Their Properties and Uses (Reinhold Publishing, New York, 1952),
Vols. 1–2.
6. Heravi, M. M.; Khorshidi, M.; Beheshtia Yahia, Sh.; Baghernejad, B.; Bull. Korean Chem. Soc.
2010, 31, 1343-1344.
7. Liu, Y.; Liang, J.; Liu, X. H.; Fan, J. C.; Shang, Z. C.; Chin. Chem. Lett. 2008, 19, 1043-1046.
8. Ren, Z. J.; Cao, W. G.; Tong, W. Q.; Synth. Commun. 2002, 32, 3475-3479.
9. Wang, X. S.; Zeng, Z. S.; Li, Y. L.; Shi, D. Q.; Tu, S. J.; Synth. Commun. 2005, 35, 1915-
1920.
10. Zhang, J. C.; Han, B. X.; Zhu, A. L.; Ma, X. M.; Synth. Commun. 2000, 36, 3305-3317.
11. Li, J. T.; Li, T. S.; Li, L. J.; Cheng, X.; Ultrason. Sonochem. 1999, 6, 199-201.
12. Kumbhare, R. M.; Sridhar, M.; Catal. Commun. 2008, 9, 403-405.
13. Ren, Y. M.; Cai, C.; Catal. Lett. 2007, 118, 134-138.
14. Cai, Y. Q.; Peng, Y. Q.; Son, G. H.; Catal. Lett. 2006, 109, 61-64.
15. Fang, D.; Fei, Z. H.; Liu, Z. L.; Monatsh. Chem. 2008, 139, 799-803.
16. Xu, D. Z.; Liu, Y. J.; Shi, S.; Wang, Y. M.; Green Chem. 2010, 12, 514-517.