Acetylation of 2-methoxynaphthalene with acetic anhydride over a HBEA zeolite

Zeolites as Catalysts for the Synthesis of Fine Chemicals

“…However, the results for the hydroxymethylation of guaiacol in the presence of mordenite with different Si/Al ratios show that the formation of mesoporous secondary structure during dealumination overlapped with the effect of the hydrophobicity in the more dealuminated catalyst, increasing the selectivity to diaryl by-products in comparison to mordenites having intermediate Si/Al ratios. Thus, it is possible to obtain conversions approximately of 20 and 60% selectivity to p-vanillin alcohol for samples with Si/Al ratios between 12 and 25, whereas for samples with higher Si/Al ratios (30)(31)(32)(33)(34)(35) the selectivity to p-vanillin alcohol is less than 40% and the diaryl by-products account for 60%. Allylation of guaiacol [59] is also a commercially important process that gives products such as eugenol, o-eugenol, and chavitol used in perfumeries, flavorings, essential oils, insect attractants, and in medicines as local antiseptic, analgesic, and UV light absorbers.…”

“…Because of the high melting point of the substrate and products, the acetylation of 2-MN is carried out in the presence of solvents, acetic anhydride being the preferred acylating agent. Because of the higher molecular size of 2-MN and 2-AMN, the reaction has been preferably performed over large pore zeolites: HY, HMor, H-Beta, and ITQ-7 [28][29][30][31][32][33][34][35], Beta zeolite being the most investigated. With this molecular sieve, the selectivity to 2-AMN is in general higher than with other large pore zeolites due to the pore dimensions.…”

“…Excellent yield (93%) of the Diels-Alder adduct is achieved after 3 hours at 60 • C. The use of furane derivatives as dienophiles is important, as they are interesting building blocks in the synthesis of biologically active compounds; however, furan is acid-sensitive and the Diels-Alder reaction of this diene using the conventional homogeneous acid catalyst leads generally to low yields. Ipaktschi [68] reported that Cu + -exchanged Y zeolite was very effective in catalyzing the Diels-Alder reaction of furan with dienophiles such as acrolein or methyl vinyl ketone at 0 • C, achieving adduct yields of 31 respectively (Scheme 25.12). Similar results were reported by Narayana et al [69] using Ce-exchanged Y zeolite, while Zn-Y zeolite is a less active and stereoselective catalyst.…”

Metal Triflates Incorporated in Mesoporous Catalysts for Green Synthesis of Fine Chemicals

“…Previous studies [43] showed that in the presence of zeolites, as catalysts, the nonpolar solvents determine a strong inhibition of acetylation by the very polar products (acetic acid, acetylated products), whereas highly polar solvents competed with the reactant molecules to enter the pores and adsorb on the acidic sites with, therefore, a significant limitation in the acetylation rate. Based on this, the first stage of our research was focused on a screening of different solvents in the acylation of phenol to ohydroxyacetophenone.…”

Acylations with Long-Chain Acid Anhydrides and Acyl Chlorides over Zeolite Beta

“…Several papers and reviews [10][11][12][13], in which zeolites were successfully used for production of important intermediates or products of fine chemicals by acylation were published. Acylation of anisole [14][15][16][17], veratrole [18,19], naphthalene [20,21], 2-methoxynaphthalene [22][23][24], toluene [25,26], isobutylbenzene [27], phenol [28,29] or heterocycles [30,31] belong among very important acylation reaction catalyzed with zeolite catalysts. The products of anisole and veratrole acylation are important flavor materials.…”