- CuCr2O4 derived by the sol-gel method as a highly active and selective catalyst for the conversion of glycerol to 2,6-dimethylpyrazine: A benign and eco-friendly process
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Vapour phase dehydrocyclization of crude glycerol in conjunction with 1,2-propanediamine (1,2-PDA) was examined over CuCr2O4 obtained by different preparation methods. A high proportion of copper species interacted with Cr2O3 in CuCr2O4 derived from the sol-gel route with a low ratio of Cu2+/Cu0 demonstrating higher dehydrocyclization activity and 2,6-dimethylpyrazine (2,6-DMP) selectivity. X-ray photoelectron spectroscopy analysis of the reduced CuCr2O4 revealed a lower fraction of ionic Cu and a high percentage of metallic Cu in the near surface region. The HCOOH and pyridine adsorbed DRIFT spectra of CuCr2O4 revealed that strong basic and moderate Lewis acid sites are responsible for the selective formation of 2,6-dimethylpyrazine which is consistent with the catalyst poisoning studies on CuCr2O4 co-feeding with pyridine as both Br?nsted and Lewis acid site blocker and 2,6-lutidine as a selective Br?nsted acid site blocker during the dehydrocyclization reaction. The presence of isolated CuO and Cr2O3 species led to a high selectivity for 2,6-dimethylpiperazine. The high intrinsic activity of CuCrsol-gel was also concomitant with the Cu metal surface areas of the catalysts. The fresh, reduced and some of the used catalysts are characterized by BET-surface area, powder XRD, FTIR, XPS, TEM, H2-TPR, TPD of NH3, pyridine, 2,6-dimethylpyridine and HCOOH adsorbed DRIFT spectroscopy.
- Vankudoth, Krishna,Gutta, Naresh,Velisoju, Vijay Kumar,Mutyala, Suresh,Aytam, Hari Padmasri,Akula, Venugopal
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- The role of Lewis acid-base pair sites in ZnO-ZnCr2O4 catalysts for cyclization: Via dehydrogenative condensation of crude glycerol and 1,2-propanediamine for the synthesis of 2,6-dimethylpyrazine
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Nano-crystalline mixed oxides of ZnO-ZnCr2O4 (ZC) derived from Zn-Cr-HT precursors were examined for the vapor phase dehydrogenative condensation of crude glycerol and 1,2-propanediamine (1,2-PDA) to synthesize 2,6-dimethylpyrazine (1,2-DMP). The nature of the surface active sites is illustrated by BET-SA, XRD, ESR, H2-TPR, TPD of NH3, TEM, XPS, and pyridine and HCOOH adsorbed DRIFT spectroscopy. The role of acid-base sites in the product distribution is discussed using the catalytic activity data under a kinetic regime. The in situ IR studies revealed that the dehydration of glycerol occurs on weak Lewis acid sites and dehydrogenation takes place on strong basic sites on the catalyst surface. A relationship between surface acid-base strength and the 2,6-DMP rate is established.
- Vankudoth, Krishna,Padmasri, A. Hari,Sarkari, Reema,Velisoju, Vijay Kumar,Gutta, Naresh,Sathu, Naveen Kumar,Rohita,Akula, Venugopal
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- The invention relates to a propylene glycol and liquid ammonia as raw materials for preparing propylene diamine method and apparatus thereof
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The invention relates to a method for preparing propane diamine by taking propylene glycol and liquid ammonia as raw materials. Propylene glycol and liquid ammonia are mixed in a certain ratio and are pumped into a reactor by virtue of a pump, and reaction is carried out in presence of a catalyst and hydrogen. The method for preparing the propane diamine by taking the propylene glycol and liquid ammonia as the raw materials has the advantages that a novel catalyst is adopted, catalytic performance is excellent, and long-time operation can be easily carried out; propylene glycol is subjected to hydroamination for producing a propane diamine product at lower reaction pressure, and reaction conditions are adjusted and changed, so that composition of the product can be flexibly adjusted and changed, selectivity of a target product is improved, a reaction process is simple, one-time investment of a production unit and production cost are reduced, a reaction product and a catalyst can be simply separated, and large-scale continuous industrial production can be easily realized.
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Paragraph 0052-0053; 0089
(2017/08/31)
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- Structure of catalytically active Rh-In bimetallic phase for amination of alcohols
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The structure of Rh-In bimetallic catalysts supported on carbon for amination of alcohols was determined by XRD, TEM-EDX, XPS, CO adsorption and EXAFS. At low In/Rh ratio (In/Rh ≤ 0.2), Rh metal particles with sizes of a tetragonal RhIn alloy with a particle size of ～20 nm was formed. This tetragonal alloy has a structure with a = 0.315 nm and c = 0.328 nm where metal atoms are located at (0, 0, 0) and (0.5, 0.5, 0.5). The catalytic activity of the tetragonal RhIn alloy is much higher than that of Rh metal particles with or without indium oxide species. With an excess amount of In (In/Rh > 1) on the high Rh loading (20 wt%) catalyst, the cubic RhIn phase with a CsCl structure was observed instead of the tetragonal RhIn phase, and the catalytic activity was much decreased.
- Takanashi, Tsukasa,Tamura, Masazumi,Nakagawa, Yoshinao,Tomishige, Keiichi
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p. 28664 - 28672
(2014/07/22)
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- METHOD FOR PRODUCING AMINES FROM GLYCERIN
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The present invention relates to a process for preparing amines by reacting glycerol with hydrogen and an aminating agent from the group of ammonia and primary and secondary amines in the presence of a catalyst at a temperature of from 100° C. to 400° C. and a pressure of from 0.01 to 40 MPa (from 0.1 to 400 bar). Preference is given to using glycerol based on renewable raw materials. The catalyst preferably comprises one metal or a plurality of metals or one or more oxygen compounds of the metals of groups 8 and/or 9 and/or 10 and/or 11 of the Periodic Table of the Elements. The invention further relates to the use of the reaction products as an additive in cement or concrete production and in other fields of use. This invention further provides the compounds 1,2,3-triaminopropane, 2-aminomethyl-6-methylpiperazine, 2,5-bis(aminomethyl)piperazine and 2,6-bis(aminomethyl)piperazine.
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Page/Page column 12-13; 14
(2010/10/03)
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- METHOD FOR PRODUCING AMINES FROM SUGAR ALCOHOLS
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The present invention relates to a process for preparing amines by reacting sugar alcohols with hydrogen and an aminating agent selected from the group of ammonia and primary and secondary amines in the presence of a catalyst at a temperature of from 100° C. to 400° C. and a pressure of from 1 to 40 MPa (from 10 to 400 bar). The catalyst preferably comprises one metal or a plurality of metals or one or more oxygen compounds of the metals of groups 8 and/or 9 and/or 10 and/or 11 of the Periodic Table of the Elements. The sugar alcohol is preferably obtained by hydrogenating the corresponding sugars. The invention further relates to the use of the reaction products as an additive in cement or concrete production and in other fields of use.
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Page/Page column 10
(2010/12/29)
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- 5-HT2 RECEPTOR LIGANDS
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Described herein are 5-HT2 receptor-selective compounds of Formula I: STR1 wherein: A and B are independently selected, optionally substituted, saturated or unsaturated 5-or 6-membered, homo-or heterocyclic rings;X 1 is selected from CH 2, O, NH, S, C=O, CH--OH, CH--N(C 1-4 alkyl) 2, C=CHCl, C= CHCN, N--C 1-4 alkyl, N-acetyl, SO 2 and SO;X. sub.2---is selected from N=, CH 2--, CH=, C(O)--, O--, and S--;R 1 is C 1-6 alkyl optionally substituted with a substituent selected from OH, halo, C 1-4 alkyl and C 1-4 alkoxy; andR 2, R 3 and R 4 are independently selected from H and R 1 ;and acid addition salts, solvates and hydrates thereof. Their use as ligands for serotonin 5-HT2 receptor identification and in a drug screening program, and as pharmaceuticals to treat indications in which the 5-HT2 receptor is implicated, such as hypertension, thrombosis, migraine, vasospasm, ischemia, depression, anxiety, schizophrenia, sleep disorders and appetite disorders is also described.
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- Antiatherosclerotic and antithrombotic 1-benzopyran-4-ones and 2-amino-1,3-benzoxazine-4-ones
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This invention relates to compounds of Formula I STR1 which are useful in association with a pharmaceutical carrier as antiatherosclerotic agents. In addition, various compounds of Formula I are useful inhibitors of cell proliferation.
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- Antiatherosclerotic and antithrombotic 2-amino-6-phenyl-4H-pyran-4-ones
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This invention relates to compounds of Formula I STR1 which are useful as antiatherosclerotic agents and inhibitors of cell proliferation for the treatment of proliferative diseases. In addition, various compounds of Formula I are useful inhibitors of platelet aggregation.
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- A New Method for Obtaining Isotopic Fractionation Data at Multiple Sites in Rapidly Exchanging Systems
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A new method for rapidly and conveniently obtaining isotopic fractionation factors in dilute aqueous solutions of compounds containing rapidly exchanging OH, NH, and SH groups is described.Shifts in the positions of NMR peaks for spectroscopically observable nuclei induced by isotopic substitution are the basis of this procedure which has the unique capability of separately measuring the isotopic exchange constants simultaneously for several different groups in the same molecule.The results for a series of alcohols, amines, thiols, phenols, acids, and amides with use of 13C NMR spectroscopy are reported.Atypically low values of Kfrac are observed in several cases, indicating that there are strong internal hydrogen bonds in competition with those to water, yielding conformational information.
- Jarret, Ronald M.,Saunders, Martin
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p. 2648 - 2654
(2007/10/02)
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- Alicyclic Nitrosamines and Nitrosamino Acids as Transnitrosating Agents
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Many alicyclic nitrosamines act as nitrosating agents under mild conditions (pH 1-3, in the presence of nucleophilic catalysts such as thiocyanate).All nitrosopiperazines, nitrosomorpholines, and nitrosamino acids tested were found to act as nitrosating agents, and certain nitrosopiperidines also showed this capability.Acyclic nitrosamines are far less reactive than functionally similar cyclic compounds.
- Singer, Sandra S.,Singer, George M.,Cole, Barbara B.
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p. 4931 - 4935
(2007/10/02)
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