626-86-8Relevant articles and documents
Oxidation of cyclohexanone and/or cyclohexanol catalyzed by Dawson-type polyoxometalates using hydrogen peroxide
Dermeche, Leila,Idrissou, Yasmina,Mazari, Tassadit,Moudjahed, Mohammed,Rabia, Cherifa
, (2022/03/07)
The oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture using as catalyst, Dawson-type polyoxometalates (POMs) of formula, α- and β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 and hydrogen peroxide, carried out at 90 °C with a reaction time of 20 h, led to a high number of mono- and di-acids which were identified by GC-MS. Levulinic, 6-hydroxyhexanoic, adipic, glutaric and succinic acids, major products were evaluated by HPLC. Regardless of the substrate nature, all POMs exhibited high catalytic activity with 94–99% of conversion, whereas the formation of the different products is sensitively related to both the composition and symmetry of the POMs and the substrate nature. The main products are adipic acid in the presence of α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62, levulinic acid in the presence of α1-K7P2Mo5VW12O62 and β-K6P2W18O62 and 6-hydroxyhexanoic acid in the presence of α- and β-K6P2W18O62. Graphical abstract: High catalytic activity was observed with?α- and?β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 Dawson-type for the oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture, in the hydrogen peroxide presence, to several oxygenated products. Adipic, levulinic and 6-hydroxyhexanoic acids are the main products. The peroxo- species formed in situ could be the active sites.[Figure not available: see fulltext.]
An adipic acid monoethyl synthetic method (by machine translation)
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Paragraph 0027; 0028; 0029; 0030; 0031; 0031; 0032-0082, (2017/09/01)
An adipic acid monoethyl synthetic method, steps: firstly the adipic acid, acid, ethanol and water in the organic solvent heating and thermal insulation, and then removing the acid water level after the end of the thermal insulation layer, acid aqueous layer is re-used for the next round of the reaction, the organic layer obtained; the obtained organic layer concentrated, get the adipic acid monoethanol at the beginning of ester concentrate; will be adipic acid monoethanol at the beginning of ester concentrate extracted by the extractant continuous flow extraction purification, then the concentrated adipic acid monoethyl. The reaction mechanism is simple, short reaction time, adipic acid monoethyl of mol yield can be up to 97 - 98%, purity can be up to 99% or more; the consumption of acid and alkali is significantly reduced; the separate acid water layer can be repeatedly applied to the next round of reaction; simple process flow, simple operation, reducing the energy consumption, the labor intensity; reflect the green production; extraction process is simple, rapid and effective, and the extractant used after processing, saving the operation cost, easy industrialization enlarges the production and continuous operation. (by machine translation)
Selective monomethyl esterification of linear dicarboxylic acids with bifunctional alumina catalysts
Santacroce, Veronica,Bigi, Franca,Casnati, Alessandra,Maggi, Raimondo,Storaro, Loretta,Moretti, Elisa,Vaccaro, Luigi,Maestri, Giovanni
supporting information, p. 5764 - 5768 (2016/11/06)
An environmentally friendly protocol for the selective protection of dicarboxylic acids is reported using methanol as a cheap esterifying agent and alumina as a heterogeneous catalyst; the selectivity of the process has been ascribed to a balanced acidity/basicity of the bifunctional alumina catalyst.