627-91-8Relevant 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.]
Preparation method 6 -hydroxy caproic acid
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Paragraph 0056; 0071-0077; 0093; 0099-0101; 0107; 0113-0115, (2021/11/10)
The invention provides a preparation method of 6 -hydroxycaproic acid. The method comprises the following steps: 1) subjecting 1 and 6 - adipic acid to intramolecular dehydration to obtain adipic anhydride. 2) The adipic acid anhydride is reacted with fatty alcohol to obtain the adipic acid monoester. 3) The adipic acid monoester was subjected to a reduction reaction under hydrogen pressure to give 6 - hydroxycaproic acid. 1-hydroxycaproic acid is prepared by taking 6 - and 6 - adipic acid cheap and easily available as raw materials through intramolecular dehydration, ring opening esterification, hydrogenation reduction and the like.
NOVEL ESTERIFICATION CATALYST AND USES THEREOF
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Page/Page column 0026; 0028-0029, (2020/07/07)
Tin (II) glucarate is found to be effective alone and in combination with other tin compounds for catalyzing the reaction of carboxylic acids such as furan-2,5-dicarboxylic acid, terephthalic acid and adipic acid with alcohols such as the C1-C3 alcohols.