Catalytic acetylation of (+)-cedrol with heterogeneous catalyst H2SO4/SiO2 under solvent free conditions

Abstract

ISSN: 2410-9649 Elvia et al. / Chemistry International 1(3) (2015) 196-201 iscientic.org. 197 www.bosaljournals/chemint/ editorci@bosaljournals.com household cleaners, and detergents (Bhatia et al., 2008). Cedrol can be converted to cedryl acetate by acetylation. Acetylation of alcohols is an important and routinely utilized transformation in organic chemistry (Subhan et al., 2001). Specifically, acetylation refers to that process of introducing an acetyl group into a compound, namely, the substitution of an acetyl group for an active hydrogen atom. A reaction involving the replacement of the hydrogen atom of a hydroxyl group with an acetyl group (CH3 CO) yields a specific ester, the acetate. The most notable of acetic anhydride is for the acetylation of alcohols used reagent combination for this reaction in the presence of acid or base catalysts (Pearson et al., 1999). Tertiary alcohols have been esterified in good yields using acetic anhydride with calcium hydride or calcium carbide, t-butanol can be esterified to t-butyl acetate in 80% yield under these conditions (Pearson et al., 1999). Various catalyst such as zeolite H-FER (Subhan et.al., 2001), Zr(HSO4)4 (Chakraborti et al, 2009), silver triflate (Das et al., 2011), silica sulfuric acid (Shirini et al., 2005), lithium (bisfluorosulfonyl)-imide (Li et al., 2012), iodine (Phukan, 2004) and heteropolyacid (Heravi et al., 2007) have also been used for the acetylation of alcohols. Most of these reported catalyst used Ac2O as acetylating agent. Herein we report the acetylation of (+)cedrol compound by using acetic anhydride in the presence of a catalytic amount of H2SO4/SiO2 under solvent free conditions (Scheme 1). Silica sulfuric acid as an efficient and reusable heterogeneous catalyst was used for the preparation of 2H-indazolo[2,1-b]phtalazine-triones (Shaterian et al., 2008) and it was efficient reagent for the acetylation of alcohols in solution and under solvent free conditions (Shirini et al., 2004). MATERIALS AND METHODS