2620-05-5Relevant articles and documents
Proton Chelating Ligands Drive Improved Chemical Separations for Rhodium
Narita, Hirokazu,Nicolson, Rebecca M.,Motokawa, Ryuhei,Ito, Fumiyuki,Morisaku, Kazuko,Goto, Midori,Tanaka, Mikiya,Heller, William T.,Shiwaku, Hideaki,Yaita, Tsuyoshi,Gordon, Ross J.,Love, Jason B.,Tasker, Peter A.,Schofield, Emma R.,Antonio, Mark R.,Morrison, Carole A.
, p. 8720 - 8734 (2019)
Current methods for the extraction of rhodium carry the highest carbon footprint and worst pollution metrics of all of the elements used in modern technological applications. Improving upon existing methods is made difficult by the limited understanding of the molecular-level chemistry occurring in extraction processes, particularly in the hydrometallurgical separation step. While many of the precious metals can be separated by solvent extraction, there currently exist no commercial extractants for Rh. This is due to its complicated mixed speciation upon leaching into hydrochloric acid, which gives rise to difficulties in designing effective reagents for solvent extraction. Herein we show that the diamidoamine reagent N-n-hexylbis(N-methyl-N-n-octylethylamide)amine transports Rh(III) from aqueous HCl into an organic phase as the monoaquated dianion [RhCl5(H2O)]2- through the formation of an outer-sphere assembly; this assembly has been characterized by experimentation (slope analysis, FT-IR and NMR spectroscopy, EXAFS, SANS, and ESI-MS) and computational modeling. The paper demonstrates the importance of applying a broad range of techniques to obtain a convincing mode of action for the complex processes involved in anion recognition in the solution phase. A consistent and comprehensive understanding of how the ligand operates to achieve Rh(III) selectivity over the competitor anion Cl- has emerged. This knowledge will guide the design of extractants and thus offers promise for improving the sustainability of metal extraction from both traditional mining sources and the recycling of secondary source materials.
Photodegradation of metolachlor: Isolation, identification, and quantification of monochloroacetic acid
Wilson, Ruth I.,Mabury, Scott A.
, p. 944 - 950 (2000)
The photolysis of metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2- methoxy-l-methylethyl) acetamide] in a sunlight simulator under actinic radiation was investigated. The focus of the study was to determine the extent of monochloroacetic acid (MCA) production. MCA was concentrated and derivatized from photolysate as the n-propyl ester using propanol and sulfuric acid and then identified as the ester using GC/MS and GC/ECD. On the basis of regression analysis, it was shown that the direct photodegradation of ~10 μM metolachlor followed pseudo-first-order kinetics with respect to the metolachlor concentration, and the half-life of the herbicide (~74 h) was independent of the pH of the medium. Photolysis in synthetic field water (SFW) resulted in a significant reduction of photolysis time (t 1/2 ~ 9 h). Direct photolysis experiments indicate a 5.19 ±0.81% (n=3) conversion of metolachlor to MCA, while photolysis in synthetic field water and in a Don River water sample resulted in 29.8 ± 4.6% (n = 3) and 12.6 ± 4.1% (n = 3) conversion, respectively; MCA was shown to be hydrolytically stable over the time course of the photoreaction. The photodegradation of alachlor, butachlor and a model chloroacetanilide, 2-chloro-N-methylacetanilide, in SFW were also investigated.
Intramolecular carbene C-H insertion reactions of 2-diazo-2-sulfamoylacetamides
Que, Chuqiang,Huang, Peipei,Yang, Zhanhui,Chen, Ning,Xu, Jiaxi
, (2019)
The intramolecular C-H insertions of carbenes derived from 2-diazo-2-sulfamoylacetamides were studied. 2-Diazo-2-sulfamoylacetamides were first prepared from chloroacetyl chloride and secondary amines through acylation followed by sequential treatments with sodium sulfite, phosphorus oxychloride, secondary amines, and 4-nitrobenzenesulfonyl azide. The results indicate that: (1) 2-diazo-N,N-dimethyl-2-(N,N-diphenylsulfamoyl)acetamide can take the formal aromatic 1,5-C-H insertion in its N-phenylsulfonamide moiety to afford the corresponding 1,3-dihydrobenzo[c]isothiazole-3-carboxamide 2,2-dioxide derivative; (2) no aliphatic C-H insertions occur for 2-diazo-2-(N,N-dialkylsulfamoyl)acetamides; and (3) for 2-diazo-N-phenyl-2-(N-phenylsulfamoyl)acetamides, the formal aromatic 1,5-C-H insertion in the N-phenylacetamide moiety is favorable to afford the corresponding 3-sulfamoylindolin-2-one derivatives as sole or major products. The intramolecular competitive aromatic 1,5-C-H insertion reactions of 2-diazo-2-sulfamoylacetamides with aryl groups on both amide and sulfonamide groups reveal that the N-aryl substituents on acetamide are more active than those on sulfonamide. The chemoselectivity is controlled by electronic effect of the aryl group.
Synthesis of asymmetrically substituted cyclen-based ligands for the controlled sensitisation of lanthanides
Borbas, K. Eszter,Bruce, James I.
, p. 2274 - 2282 (2007)
A series of unsymmetrical cyclen-based ligands incorporating an antenna and a quencher have been prepared for the complexation of the visible- (Eu, Tb) and near IR-emitting (Nd, Yb) lanthanides. Eu and Tb were sensitised with coumarin 2, and Nd and Yb with rhodamine. Both antennae were paired with nucleoside (uridine and adenosine) quenchers. The interaction between the quencher and the antenna can be regulated by the addition of the complementary base or DNA to the complexes, resulting in changes in the lanthanide luminescence intensity and lifetime. The Royal Society of Chemistry.
Synthesizing method for chloroacetamide compound
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Paragraph 0043-0045, (2019/10/01)
The invention discloses a synthesizing method for a chloroacetamide compound. In a reaction kettle, a secondary amine compound is dissolved in an organic solvent, the mixture is heated for reflux, chloroacetyl chloride is added into the mixture, a reflux reaction is conducted for 0.5-20 hours, and the chloroacetamide compound is obtained. According to the synthesizing method for the chloroacetamide compound, an acid binding agent is not used, discharging of wastewater in the after-treatment process is reduced, by keeping the reflux state of the system, hydrogen chloride gas generated from thereaction is exhausted out of the system and absorbed by water outside the system, high-purity hydrochloric acid is obtained, the waste is turned into wealth, the method comes up to the production standard of safety and environment protection, and discharging of waste gas, waste water and waste residues is reduced; according to the synthesizing method for the chloroacetamide compound, few operationsteps are utilized, the reaction speed is high, the product yield is high, the purity is high, the production cost is low, and the method is safe, friendly to the environment and suitable for industrial large-scale production.
Efficient synthesis, spectroscopic characterization and DFT based studies of novel 1-amide 4-sulfonamide-1,2,3-triazole derivatives
Bonyad, Sarvenaz Rouhi,Mirjafary, Zohreh,Saeidian, Hamid,Rouhani, Morteza
, p. 164 - 170 (2019/07/18)
In the present study, for the first time 1-amide 4-sulfonamide-1,2,3-triazole scaffolds were synthesized by using an azide-alkyne Huisgen cycloaddition reaction. The target products were obtained in moderate to good yields (45–75%) by using catalytic CuI and green system H2O/EtOH. The easy availability of the inexpensive starting materials, avoiding isolation and handling of hazardous organic azides and mild reaction conditions make this method a valuable tool for generating functionalized 1,2,3-triazole derivatives. The unambiguous characterization of synthesized compounds was accomplished by using various spectroscopic techniques such as 1H NMR, 13C NMR, and FT-IR. The information regarding optimized geometry, were obtained by applying DFT/B3LYP-6-31G(d) method. The electrophilicity index, 1H and 13C chemical shift values, lithium and sodium ion affinities of the desired product 3b have been also calculated by the mentioned method. As a whole, the calculated results were found in close agreement to that of experimental data. The studies revealed that the compound 3b possesses good Li+ and Na+ affinity and cation π interaction plays a vital role in the complexation of 3b. For the first time, nucleus–independent chemical shift index was used to confirm the cation π interaction of 3b.
Palladium-catalyzed olefination of aryl/alkyl halides with trimethylsilyldiazomethane via carbene migratory insertion
Mu, Qiu-Chao,Wang, Xing-Ben,Ye, Fei,Sun, Yu-Li,Bai, Xing-Feng,Chen, Jing,Xia, Chun-Gu,Xu, Li-Wen
supporting information, p. 12994 - 12997 (2018/11/23)
The direct olefination of aryl/alkyl halides with trimethylsilyldiazomethane (TMSD) as a C1- or C2-unit was achieved successfully via a metal carbene migratory insertion process, which offered a new access to afford (E)-vinyl silanes and (E)-silyl-substituted α,β-unsaturated amides in good yields and high chemoselectivity.
Latent Bronsted Base Solvent-Assisted Amide Formation from Amines and Acid Chlorides
Otsuka, Rikuto,Maruhashi, Kazuo,Ohwada, Tomohiko
supporting information, p. 2041 - 2057 (2018/05/04)
Weakly basic amines, including even neutral amines such as nitroaniline and aminocarboxylic acids, react with acid chlorides very efficiently in N, N -dimethylacetamide (DMAC), without addition of a base, to give the corresponding amides in high yields. The role of DMAC and related solvents as latent Bronsted bases was studied in these amidation reactions. Less basic amines, such as aromatic amines, reacted with benzoyl chloride faster than more basic aliphatic amines.
Synthesis and structure-activity relationships of LP1 derivatives: N-methyl-N-phenylethylamino analogues as novel MOR agonists
Turnaturi, Rita,Parenti, Carmela,Prezzavento, Orazio,Marrazzo, Agostino,Pallaki, Paschalina,Georgoussi, Zafiroula,Amata, Emanuele,Pasquinucci, Lorella
, (2018/03/26)
The opioid pharmacological profile of cis-(-)-N-normetazocine derivatives is deeply affected by the nature of their N-substituents. Here, our efforts were focused on the synthesis and pharmacological evaluation of novel derivatives of the lead LP1, a multitarget opioid analgesic compound featuring an N-phenylpropanamido substituent. LP1 derivatives 5a-d and 6a-d were characterized by flexible groups at the N-substituent that allow them to reposition themselves relative to cis-(-)-N-normetazocine nucleus, thus producing different pharmacological profiles at the mu, delta and kappa opioid receptors (MOR, DOR and KOR) in in vitro and in vivo assays. Among the series, compound 5c, with the best in vitro and in vivo profile, resulted a MOR agonist which displays a KiMOR of 6.1 nM in a competitive binding assay, and an IC50 value of 11.5 nM and an Imax of 72% in measurement of cAMP accumulation in HEK293 cells stably expressing MOR, with a slight lower efficacy than LP1. Moreover, in a mouse model of acute thermal nociception, compound 5c, intraperitoneally administered, exhibits naloxone-reversed antinociceptive properties with an ED50 of 4.33 mg/kg. These results expand our understanding of the importance of N-substituent structural variations in the opioid receptor profile of cis-(-)-N-normetazocine derivatives and identify a new MOR agonist useful for the development of novel opioid analgesics for pain treatment.
Anti-proliferative activity, molecular modeling studies and interaction with calf thymus DNA of novel ciprofloxacin analogues
Suresh, Narva,Suresh, Amaroju,Yerramsetty, Suresh,Bhadra, Manika Pal,Alvala, Mallika,Sekhar, Kondapalli Venkata Gowri Chandra
, (2018/08/24)
Abstract: In our pursuit to expand new potential anticancer leads, a series of eighteen novel 1-cyclopropyl-6-fluoro-4-oxo-7-(4-substituted piperazin-1-yl)-1,4-dihydroquinoline-3-carboxylic acid analogues have been synthesized, characterized and evaluated anti-proliferative activity against five human cancer cell lines such as A549 (lung cancer), Mia Paca (pancreatic cancer), HeLa (cervical cancer), MDA MB-231 (breast cancer), MCF-7 (breast cancer) and normal embryonic kidney?cell line (HEK) were carried out using MTT assay. Few of the synthesized analogues exhibited potent anticancer activity against the cancer cell lines at a lower concentration. The synthesized compounds showed the less toxic effect on normal human embryonic kidney?cell line (HEK) compared with doxorubicin. Noticeably, compound 3o exhibited potent activity against all five cancer cell lines compared with ciprofloxacin. Further study exposed that compound 3o could competently intercalate into calf thymus DNA to form 3o-DNA complex which might block DNA replication to apply anti-proliferative activity. Docking simulation studies supported by molecular interactions with DNA type II topoisomerase. These derivates can become lead structures for the development of potential anticancer drugs. Graphical Abstract: Eighteen CP analogues were synthesized and evaluated for anti-proliferative activity. The interactions with DNA topoisomerase II were supported by molecular docking studies. 3o showed promising anticancer activity than CP against MCF7 cell line and interaction with calf thymus DNA was studied by fluorescence spectroscopy.[Figure not available: see fulltext.].
