Alkaline earth layered benzoates as reusable heterogeneous catalysts for the methyl esterification of benzoic acid

Abstract

Recebido em 9/8/11; aceito em 9/4/12; publicado na web em 2/7/12 This paper describes the synthesis and characterization of layered barium, calcium and strontium benzoates and evaluates the potential of these materials as catalysts in the synthesis of methyl benzoate. The methyl esterification of benzoic acid was investigated, where the effects of temperature, alcohol:acid molar ratio and amount of catalyst were evaluated. Ester conversions of 65 to 70% were achieved for all the catalysts under the best reaction conditions. The possibility of recycling these metallic benzoates was also demonstrated, evidenced by unaltered catalytic activity for three consecutive reaction cycles.

Mixing Effect on Stoichiometric Diversity in Benzoic Acid–Sodium Benzoate Cocrystals

“…PXRD patterns of NaBz, HBz, 1:1 and 2:1 cocrystals of HBz–NaBz are shown in Figure whose characteristic diffraction peaks are at 2θ = 6.4°, 23.8°, 6°, and 7.2°, respectively. ,,, In our present study, all harvested 2:1 cocrystals of HBz–NaBz are Form A . The diffraction patterns of NaBz and HBz in Figure a,b can easily be distinguished from the ones of both cocrystals in Figure c,d.…”

Biochemical studies on a versatile esterase that is most catalytically active with polyaromatic esters

“…polymers produced with versatile photo-reactivities) (Noh et al ., 2001 ; Chae et al ., 2002 ; Zhu et al ., 2011 ). Heterogeneous catalysts have successfully been used to produce PAH-like (naphthalene, anthracene, phenanthrene, benzyl and phthalate) derivatives (Noh et al ., 2001 ; Zhu et al ., 2011 ; Maruyama et al ., 2012 ). However, to the best of our knowledge, no study in the specialized literature has involved identification of potential applications for esterase/lipase-like proteins as catalysts for modifying PAHs.…”

“…Our data show that CN1E1 is, to the best of our knowledge, the first efficient and catalytically active esterase from the α/β-hydrolase family for PAH ester hydrolysis; this suggests that this protein may be applied to generate a unique set of complex a la carte aromatic molecules with improved or unknown properties (Storms and Farrar, 1995 ; Noh et al ., 2001 ; Chae et al ., 2002 ; Yen et al ., 2005 ; Jones and Sumner, 2006 ; Zhu et al ., 2011 ; Kita et al ., 2012 ; Maruyama et al ., 2012 ). We believe that CN1E1 may expand the enzyme toolbox for new biotechnological opportunities involving heterocyclic aromatic compounds for future studies due to the inherent properties of enzymes compared with chemical heterogeneous-based processes and the unusual substrate range and preference and regio-and enantio-selective properties of CN1E1 compared with previously reported esterases.…”

Isopropyl Octanoate Synthesis Catalyzed by Layered Zinc n-Octanoate

“…Laurates of transition metals and benzoates of alkaline earth metals have been employed successfully for the production of methyl laurate and methyl benzoate, respectively. 11,12 Research into new catalytic systems is facilitated by the use of alternative experimental designs, such as the Box-Behnken design (BBD), which is a factorial planning with three levels consisting of three interlocked 2 2 designs and a central point, in order to reduce the number of experiments that are required during the investigation of complex matrices. 13 BBD has mainly been applied to optimize extraction of several analytes, synthesis/ derivatization reactions, chromatographic separation and electrochemical processes, but has not yet been applied for esterification of octanoic acid with isopropanol.…”