6850-40-4Relevant academic research and scientific papers
Effect of Zr on catalytic performance of unsupported Ni(Zr)Mo and Ni(Zr)W sulfide catalysts for quinoline hydrodenitrogenation
Jiang, Zongxuan,Li, Can,Liu, Tiefeng,Liu, Xinyi,Zhang, Cen
, (2020/08/19)
To increase the dispersion of active species and full utilization of active metals are of great importance for hydrodenitrogenation (HDN) performance of unsupported hydrotreating catalysts. Herein, a series of unsupported Ni(Zr)MoS and Ni(Zr)WS catalysts were prepared from Ni(Zr) layered double hydroxide (LDH) precursors. The Zr species remarkably promote the dispersion and reducibility of NiMo and NiW composite species. Also, the total HDN rate constants are increased from 2.42 h?1 to 9.18 h?1 for Ni(Zr)MoS and from 5.68 h?1 to 23.0 h?1 for Ni(Zr)WS, and exhibit a maximum at a Zr/Ni atomic ratio of about 0.04. The HDN selectivities indicate that the Zr species increase the number of superficial active sites without affecting their structure. The present work shows that the crystallinity of LDH precursors is crucial to the structure of unsupported sulfide catalysts, and a suitable amount of Zr could be a dispersive promoter to increase the HDN activity.
Ring opening of 1,2,3,4-tetrahydroquinoline and decahydroquinoline on MoS2/γ-Al2O3 and Ni-MoS 2/γ-Al2O3
Gutierrez, Oliver Y.,Hrabar, Ana,Hein, Jennifer,Yu, Yanzhe,Han, Jinyi,Lercher, Johannes A.
, p. 155 - 168 (2013/01/14)
The hydrodenitrogenation of decahydroquinoline (DHQ) and quinoline on MoS2/γ-Al2O3 and Ni-MoS 2/γ-Al2O3 proceeds via two routes. The first one proceeds via DHQ → propylcyclohexylamine → propylcyclohexene → propylcyclohexane, and the ring opening in DHQ is the rate-limiting step. The second route proceeds via 1,2,3,4-tetrahydroquinoline (14THQ) → o-propylaniline → propylcyclohexylamine and propylbenzene with the ring opening of 14THQ and the hydrogenation of o-propylaniline being the rate determining steps (the intrinsic rate of C(sp3)-N bond cleavage being slower in 14THQ than in DHQ). The active sites for the ring opening via Hofmann elimination are acidic -SH groups and basic S2- ions. The parallel conversion of dibenzothiophene (DBT) via direct desulfurization provides increasing concentrations of S2- ions and -SH groups. Nickel facilitates the adsorption of H2S and H2 and the mobility of hydrogen. Thus, the presence of DBT and Ni accelerates the rate of the C(sp3)-N bond cleavage. H2S as sulfur source enhances the ring-opening steps in a minor extent than DBT. The presence of -SH groups and the effect of Ni on them were probed by TPR, TPD and IR-spectroscopy of adsorbed 2,6-dimethylpyridine.
Novel selective inhibitors of neutral endopeptidase for the treatment of female sexual arousal disorder. Synthesis and activity of functionalized glutaramides
Pryde, David C.,Maw, Graham N.,Planken, Simon,Platts, Michelle Y.,Sanderson, Vivienne,Corless, Martin,Stobie, Alan,Barber, Christopher G.,Russell, Rachel,Foster, Laura,Barker, Laura,Wayman, Christopher,Van Der Graaf, Piet,Stacey, Peter,Morren, Debbie,Kohl, Christopher,Beaumont, Kevin,Coggon, Sara,Tute, Michael
, p. 4409 - 4424 (2007/10/03)
Female sexual arousal disorder (FSAD) is a highly prevalent sexual disorder affecting up to 40% of women. We describe herein our efforts to identify a selective neutral endopeptidase (NEP) inhibitor as a potential treatment for FSAD. The rationale for this approach, together with a description of the medicinal chemistry strategy, lead compounds, and SAR investigations are detailed. In particular, the strategy of starting with the clinically precedented selective NEP inhibitor, Candoxatrilat, and targeting low molecular weight and relatively polar mono-carboxylic acids is described. This led ultimately to the prototype development candidate R-13, for which detailed pharmacology and pharmacokinetic parameters are presented.
