123-98-8Relevant articles and documents
Temperatures and enthalpies of solid-solid and melting transitions of the odd-numbered n-alkanes C21, C23, C25, C27, and C29
Chevallier, Virginie,Bouroukba, Mohammed,Petitjean, Dominique,Barth, Danielle,Dupuis, Paul,Dirand, Michel
, p. 1114 - 1122 (2001)
Very high purity samples of normal pentacosane and heptacosane are made by synthesis: the procedures for the C25 and C27 synthesis and the original conditions of their purification, particularly using the extraction by supercritical carbon dioxide, are described. Measurements of temperatures and enthalpies of the solid-solid transitions and of the melting transition were carried out by differential scanning calorimetry on the C25 and C27 synthetic samples and the odd-numbered homologous n-alkanes (from C21 to C29). The results show the importance of the effect of the impurities, particularly for the δ and γ crystal-crystal transition temperatures of C25 and C27. Several current data of the literature are also shown concerning the temperatures and the enthalpies of solid-solid and melting transitions of these five n-alkanes.
Synthesis of 1-Palmitoyl-2-((E)-9- and (E)-10-nitrooleoyl)- sn -glycero-3-phosphatidylcholines
Dietz, Ulrich,Frank, Andrea,Lehr, Alexander,Münch, Winfried,Nubbemeyer, Udo
supporting information, p. 3295 - 3304 (2019/08/28)
Extensive investigation of nitrated phospholipids in connection with various biologically important processes requires reliable access to suitable material. A selective chemical synthesis introducing a defined nitrofatty acid at the sn -2 position of a 2-lyso sn -glycero-3-phosphatidylcholine was developed. Given that the nitroalkene moiety of both reactant nitrofatty acid derivative and the product esters is characterised by particular sensitivity to nucleophile addition and, depending on the intermediate, subsequent olefin isomerisation and retro-Henry-type reaction, a reliable two-step ester formation was introduced. The activation of the nitrofatty acid succeeded after reaction with trichlorobenzoyl chloride, and the mixed anhydride could be isolated via extractive work-up. Subsequent reaction with 1-palmitoyl-2-lyso- sn -glycero-3-phosphatidylcholine enabled the sn -2 esterification to be achieved with high yield by using a minimum of reagents, avoiding the formation of side products and facilitating final isolation and purification.
Azelanitrile preparation method
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Paragraph 0068-0071, (2019/10/01)
The invention relates to an azelanitrile preparation method, which comprises: (1) dissolving glutaraldehyde in a solvent, adding a condensation catalyst and an optional cocatalyst, adding cyanoaceticacid in batches to maintain the temperature of the reaction solution of not more than 40 DEG C, and carrying out a condensation reaction, wherein a molar ratio of the glutaraldehyde to the cyanoaceticacid is 1:2; and (2) further adding a palladium carbon catalyst (Pd/C) to the condensation reaction liquid obtained in the step (1), introducing hydrogen gas, maintaining the pressure, heating, and carrying out a decarboxylation and hydrogenation reaction to obtain azelanitrile, wherein the hydrogen pressure is 3.0-4.0 MPa. According to the present invention, the method can perform the reaction by using the one-step method so as to eliminate the separation and purification process of the intermediate product, such that the reaction process is simple, and the cost is low.