Comparative Catalytic Performance of Silica-HNO3 and Silica-HCl for the Synthesis of Acylals from Aromatic Aldehydes

Yıl 2023, Cilt: 2 Sayı: 2, 37 - 41, 30.06.2023

Yusuf Hassan , Abdullahi Hussaini Dangani , Alain Siba Sovogui , Amina Sada Yusuf

Öz

Acylal is one of the most effective protecting groups for carbonyl functionality in organic synthesis. In this work an attempt was made for the first time to compare the performance of silica-HNO3 and silica-HCl as heterogeneous catalysts in the formation of acylals from aromatic aldehydes. Thus the silica-acid mixtures were prepared by mixing the column chromatographic grade silica gel with concentrated HNO3 and concentrated HCl to obtain free flowing powders. These powders at different ratios were used to investigate the formation of acylal from 3-nitrobenzaldehyde as a model reaction under different operating parameters. Subsequently, the optimum condition was applied in the conversion of some substituted aromatic aldehydes to their corresponding acylals. It was found that the two catalytic systems displayed almost similar catalytic performance affording the highest yield of the acylal at 83%.

Anahtar Kelimeler

Acylal, Silica, Brӧnsted acid, Aromatic aldehyde

Kaynakça

• [1] Greene, T.W., Wuts, P.G.M. (1999). Protective Groups in Organic Synthesis, 3rd ed., John Wiley and Sons, New York, USA.
• [2] Frick, J.G., Harper, R.J. (1984). Acetals as Crosslinking Reagents for Cotton. J Appl Polym Sci; 1433-1447.
• [3] Shelke, K., Sapkal, S., Kategaonkar, A., Shingate, B., Shingare, M.S. (2009). An efficient and green procedure for the preparation of acylals from aldehydes catalyzed by alum [KAl(SO4)2.12H2O]. South Afr J Chem; 62, 109-112.
• [4] Van Heerden, F.R., Huyser, J.J., Bardley, D., Williams, G., Holzapfel, C.W. (1998). Palladium-catalysed substitution reactions of geminal allylic diacetates. Tetrahedron Lett; 39, 5281-5283.
• [5] Andberg, M., Sydness, L.K. (1998). The chemistry of acylals. Part II. Formation of nitriles by treatment of acylals with trime-thylsilyl azide in the presence of a Lewis acid. Tetrahedron Lett; 39, 6361-6364.
• [6] Li, Y.Q., Cheng, L.H. (2001). A rapid and convenient synthesis of acylals from aldehydes and acetic anhydrides catalyzed by SnCl4/SiO2. Chin Chem Lett; 12, 565-568.
• [7] Nagy, N.M., Jakab, M.A., Konya, J., Antus, S. (2002). Convenient preparation of 1,1-diacetates from aromatic aldehydes cata-lyzed by zinc-montmorillonite. Appl Clay Sci; 21, 213-216.
• [8] Wang, Y.Y., Xu, Y.N., Wang, Z.Z., Dai, L.Y. (2010). A new approach to the synthesis of pentaerythritol diacetals (diketals) cata-lyzed by SO3H-functionalized ionic liquids. Chin Chem Lett; 21, 524-528.