818-88-2Relevant articles and documents
Silica-Mediated Monohydrolysis of Dicarboxylic Esters
Dyker, Gerald
supporting information, p. 6773 - 6776 (2021/12/31)
A new method for the monohydrolysis of dicarboxylic esters is presented, involving as key step a silanolysis at elevated temperatures at the silica gel surface. In the second step, the surface bound silyl esters are cleaved off under mild conditions, giving a straightforward and fast access to half esters. Based on recovered starting material generally yields well above 70 % are achieved, both, with stiff aromatic as well as flexible aliphatic substrates, as long as the ester groups involved are remote enough from each other. Otherwise competing reactions are becoming determinative, anhydride formation in the case of phthalates and decarbonylative fragmentation in the case of malonates. The new method was also successfully tested on a multigram scale with a minimalistic apparatus setup.
Synthetic method of octadecanedioic acid mono-tert-butyl ester
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Paragraph 0020-0021; 0025-0026; 0030-0031, (2020/11/22)
The invention relates to the field of organic synthesis, in particular to a synthesis method of octadecanedioic acid mono-tert-butyl ester, which comprises the following steps: carrying out reflux esterification on sebacic acid and methanol to obtain octadecanedioic acid monomethyl ester, reacting the octadecanedioic acid monomethyl ester with isobutene under the action of a composite catalyst, concentrating, alkalizing the concentrated solution, extracting, drying and filtering. Compared with the prior art, the method has the advantages that the selectivity is good, the reaction conversion rate is high, the total yield of a final product reaches 96% or above, and the purity reaches 95% or above. The adopted composite catalyst is different from a traditional acid catalyst, Fe is dopedin bismuth vanadate, bismuth vanadate crystal lattices can be introduced into defect positions, the crystallinity is changed, and the proton or electron trapping capacity of a semiconductor can be enhanced; photocatalyst activity is improved, the bismuth vanadate is loaded on the surface of lignin amine to form a core/membrane structure used for catalyzing esterification of carboxylic acid and olefin, and the catalyst can be separated and recycled by means of magnetic separation and the like, and can be repeatedly used for multiple times without reduction in catalytic effect.
Sulfonated porous organic polymer as a highly efficient catalyst for the synthesis of biodiesel at room temperature
Gomes, Ruth,Bhanja, Piyali,Bhaumik, Asim
, p. 110 - 116 (2015/11/11)
A new functionalized porous organic polymer bearing sulfonic acid groups (PDVTA-SO3H) at the pore surface with high surface area (SBET = 406 m2 g-1) and Bronsted acidity is reported. The material has been synthesized via post-synthetic sulfonation of the porous co-polymer poly-divinylbenzene-co-triallylamine (PDVTA-1) using chlorosulfonic acid as sulfonating agent. A detailed characterization of the -SO3H functionalized porous polymeric material has been carried out using N2 sorption, FT-IR and UV-vis spectroscopy, HR-TEM, FE-SEM, thermogravimetric and elemental analyses. Temperature programmed desorption of NH3 (TPD-NH3 analysis) of PDVTA-SO3H revealed a very high surface acidity of 2.3 mmol g-1. Such high acidity of PDVTA-SO3H has been explored to investigate its catalytic efficiency towards eco-friendly production of biodiesel via esterification of long-chain free fatty acids (FFA) to the respective fatty acid monoalkyl esters (FAMEs) at room temperature using methanol as reactant as well as solvent. The sulfonated porous polymer is found to be a very active and reusable solid acid catalyst giving high yields (~92-98%) of various biodiesel compounds under very mild reaction conditions.