Carboxymethylation of cinnamylalcohol with dimethyl carbonate over the slag-based catalysts

Abstract

The carboxymethylation of cinnamylalcohol with dimethyl carbonate was performed using low-cost catalysts obtained from desulfurization slag. Processing of steel slag performed by different techniques was resulted in a wide range of the catalysts with different morphological and structural properties. Catalytic evaluation of the slag catalysts illustrated diversity of the obtained results strongly dependent on the surface area, crystal morphology and basicity. Catalytic materials demonstrated high variability of the conversion (8–85%) exhibiting similar selectivity to the desired product – cinnamyl methyl carbonate (ca. 80%). A significant impact of ultrasonication on catalytic activity was observed. Comparison of the synthesized samples with commercial basic materials illustrated competitive ability of the slag catalysts. Based on the results of catalytic evaluation and product analysis the reaction network was proposed and verified by thermodynamic analysis. A kinetic model was developed to describe concentration dependencies in carboxymethylation.

Carboxymethylation of Cinnamyl Alcohol with Dimethyl Carbonate over Graphitic Carbon Nitrides

“…95 %, which was confirmed by the experiments performed with triethylamine as the catalyst. [18] A blank experiment reported in the previous paper [19] showed ca. 10 % of CA conversion after 24 h with selectivity towards the desired product of 69 %.…”

“…200 min) similarly to the dependencies reported previously in. [19] Such an increase could be, in general, related to the apparent catalyst activation due to structural transformations, leaching of the catalytically active phase into the solution, removal of strongly adsorbed species of the reactants and products by methanol generated during the reaction as well as side transformations of CA and impurities presented in CA, such as hydrolysis of cinnamaldehyde to benzaldehyde. A reaction scheme featuring side products confirmed by NMR [19] is presented in Scheme 2.…”

“…[19] Such an increase could be, in general, related to the apparent catalyst activation due to structural transformations, leaching of the catalytically active phase into the solution, removal of strongly adsorbed species of the reactants and products by methanol generated during the reaction as well as side transformations of CA and impurities presented in CA, such as hydrolysis of cinnamaldehyde to benzaldehyde. A reaction scheme featuring side products confirmed by NMR [19] is presented in Scheme 2. In addition to the reactions illustrated in Scheme 2 other side products outside of carboxymethylation pathway can be initially formed in a reversible step, blocking the surface sites.…”

“…Moreover, DMC can be used for the production of polymers or as a solvent for the metathesis reaction and Michael condensation. [12][13][14][15] Preparation of carbonate esters from DMC and corresponding alcohols (Scheme 1) was reported using various solid base and acid catalysts [11,[16][17][18][19][20][21][22] along with the homogeneous ones. [23] Heterogeneous catalysts are considered to be more preferable providing a more sustainable technology.…”

“…80 %). [18,19] A theoretical study using DFT of 1-octanol carboxymethylation with DMC in the presence of AlCl 3 as a Lewis acid catalyst allowed to reveal a crucial role in proton-transfer processes of the dipole in AlÀ Cl covalent bonding. [20] Meanwhile, 99 % yield of methyl octyl carbonate was reported over aluminium chloride (90 °C, 19 h).…”