320-51-4Relevant articles and documents
Characterization of degradation products of regorafenib by LC-QTOF-MS and NMR spectroscopy: Investigation of rearrangement and odd-electron ion formation during collision-induced dissociations under ESI-MS/MS
Baira, Shandilya Mahamuni,Srinivasulu, Gannoju,Nimbalkar, Rakesh,Garg, Prabha,Srinivas,Talluri, M.V.N. Kumar
, p. 12091 - 12103 (2017)
Regorafenib is an oral multikinase inhibitor, and it was subjected to stress conditions (hydrolysis, oxidative, thermal and photolytic) as per ICH specified conditions. The drug showed considerable degradation under hydrolysis (acidic, basic and neutral) and oxidative stress conditions, whereas it was stable under other stress conditions. A total of five degradation products (DPs) were observed and these were analyzed by using a UHPLC-DAD system. Chromatographic separation was achieved on an Acquity CSH C18 column (100 × 2.1 mm, 1.7 μ) using 0.1% formic acid and acetonitrile:methanol (80:20%, v/v) as the mobile phase in gradient mode. All DPs were characterized by LC-MS/MS, and the major degradation product (DP1) was isolated by using an HPLC preparative system from a degradation mixture and analyzed using NMR (1D and 2D NMR) and IR experiments. It was observed that protonated DP1 and DP3 undergo rearrangement reactions during collision-induced dissociations under positive electrospray ionization conditions. Additionally, in silico toxicity of the drug and its degradation products (DP1-DP5) was evaluated using TOPKAT and DEREK toxicity prediction software tools.
Preparation and characterization of diazenyl quinolin-8-ol with trifluoromethyl substituents
Yazdanbakhsh, Mohammad R.,Mahmoodi, Nosrat O.,Dabiry, Shahram
, p. 192 - 194 (2006)
The synthesis and properties of new monoazo dyes derived from the diazonium salts of 2-trifluoromethyl phenylamine and 4-chloro-3-trifluoromethyl phenylamine are considered.
Catalytic production of anilines by nitro-compounds hydrogenation over highly recyclable platinum nanoparticles supported on halloysite nanotubes
Aepuru, Radhamanohar,Bustamante, Tatiana M.,Campos, Cristian H.,Leal-Villarroel, Edgardo,Mangalaraja, Ramalinga Viswanathan,Shanmugaraj, Krishnamoorthy,Torres, Cecilia C.,Vinoth, Victor
, (2021/07/28)
Pt-nanoparticles supported on halloysite-nanotubes (HNTs) were selectively deposited onto the inner (Pt(IN)/HNT) or outer (Pt(OUT)/HNT) surface of the support to evaluate their operational stability on the cleaner and efficient hydrogenation of nitro compounds to produce their corresponding anilines. The formation of Pt0-aggregates on the inner or outer surfaces was observed, with mean particles sizes of 2.4–2.9 nm. The catalysts were evaluated using ethanol as solvent and nitrobenzene as a model substrate at a temperature of 298 K, under 1 bar of H2 pressure. The Pt(IN)/HNT catalyst showed better catalytic performance than Pt(OUT)/HNT, which was mainly attributed to the confinement effect of the Pt-nanoparticles inside the HNTs. However, the operational stability showed that Pt(OUT)/HNT retained its catalytic performance after 15 cycles, while the Pt(IN)/HNT catalyst suffered deactivation after the 5th cycle. The best catalytic system showed a moderate-to-high efficiency in the efficient hydrogenation of 7 nitro compounds used to produce their corresponding anilines, which are important pharmaceutical building blocks.
Noble metal nanoparticles supported on titanate nanotubes as catalysts for selective hydrogenation of nitroarenes
Aepuru, Radhamanohar,Bustamante, Tatiana M.,Campos, Cristian H.,Mangalaraja, Ramalinga Viswanathan,Shanmugaraj, Krishnamoorthy,Torres, Cecilia C.,de León, J. N. Díaz
, (2021/09/22)
Platinum (Pt) and palladium (Pd) nanoparticles (NPs) supported on titanate nanotubes (TiNTs) Pt@TiNT and Pd@TiNT were prepared for the liquid-phase hydrogenation of nitroarenes at 25 °C Initially, TiNT was modified with 3-aminopropyl-trimethoxysilane to provide a strong anchoring site to trap the Pt and Pd NPs, which prevent the metal NPs from leaching. As-prepared 1 wt% of metal loading catalysts were characterized by transmission electron microscopy (TEM), nitrogen adsorption–desorption isotherms, X-ray diffraction, and X-ray photoelectron spectroscopy measurements. The TEM images confirmed that the Pt (1.70 ± 0.19 nm) and Pd (2.80 ± 0.43 nm) NPs were mainly confined into the channel of TiNTs. Both catalysts exhibited excellent catalytic performances for the reduction of nitrobenzene as a model compound under mild reaction conditions. The superior catalytic activity for the hydrogenation of nitroarenes is attributed to the small size of the Pt and Pd NPs. However, the operational stability showed that Pt@TiNT retained its catalytic performance after 10 cycles, while Pd@TiNT suffered deactivation by metal sintering after the sixth cycle. The Pt@TiNT system exhibited high efficiency in the hydrogenation of different substituted nitroarenes of pharmaceuticals interest, and it showed an excellent activity and selectivity toward the production of desired substituted anilines.
Synthesis method 4- chloro -3-(trifluoromethyl)-phenylisocyanate
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, (2020/03/29)
The invention belongs to the technical field of medicines, and concretely relates to 4 - chloro - 3 3 3 (trifluoromethyl) phenylisocyanate) synthesis method. o chlorotrifluorotoluene, acetic anhydride and concentrated nitric acid to obtain 4 - nitro - 2 2-trifluoromethyl chlorobenzene, 4 - nitro - 2 2-trifluoromethyl chlorobenzene, activated carbon, FeCl. 3 · 66H2 O And hydrazine hydrate react to obtain 4 - chlorine - 3 3-trifluoromethylaniline, 4 - chloride - 3 3-trifluoromethylaniline, triphosgene and a catalyst react to obtain 4 - chlorine - 3 3 3-trifluoromethyl)-phenylisocyanate . instead of the conventional nitric/sulfuric acid mixed acid system / reaction, risks low, nitrosation FeCl impurities, reduction process. 3 · 66H2 O/Activated carbon/hydrazine hydrate system replaces traditional iron powder reduction process, has avoided the production, of a large amount of iron mud waste residue and has reduced environmental protection pressure.
Regorafenib analogues and their ferrocenic counterparts: Synthesis and biological evaluation
Wilde, Myron,Arzur, Danielle,Baratte, Blandine,Lefebvre, Dorian,Robert, Thomas,Roisnel, Thierry,Le Jossic-Corcos, Catherine,Bach, Stéphane,Corcos, Laurent,Erb, William
, p. 19723 - 19733 (2020/12/04)
Approved by the FDA in 2012, regorafenib is one of the last chance treatments for colorectal cancer. While various analogues have already been prepared, ferrocenic derivatives have never been evaluated. In this study, we prepared various ferrocene-containing derivatives of regorafenib and recorded their biological activity in kinase and cellular assays. This led to the identification of a squaramide derivative which shows a good cellular activity and three ferrocene analogues with promising activity in both kinase and cellular assays. This journal is
Commercially Available CuO Catalyzed Hydrogenation of Nitroarenes Using Ammonia Borane as a Hydrogen Source
Du, Jialei,Chen, Jie,Xia, Hehuan,Zhao, Yiwei,Wang, Fang,Liu, Hong,Zhou, Weijia,Wang, Bin
, p. 2426 - 2430 (2020/03/30)
Tandem ammonia borane dehydrogenation and nitroarenes hydrogenation has been reported as a novel strategy for the preparation of aromatic amines. However, the practical application of this strategy is subjected to the high-cost and tedious preparation of supported noble metal nanocatalysts. The commercially available CuO powder is herein demonstrated to be a robust catalyst for hydrogenation of nitroarenes using ammonia borane as a hydrogen source under mild conditions. Numerous amines (even sterically hindered, halogenated, and diamines) could be obtained through this method. This monometallic catalyst is characteristic of support-free, excellent chemoselectivity, low-cost, and high recyclability, which will favor its future utilization in preparative reduction chemistry. Mechanistic studies are also carried out to clarify that diazene and azoxybenzene are key intermediates of this heterogeneous reduction.
Cobalt oxide NPs immobilized on environmentally benign biological macromolecule-derived N-doped mesoporous carbon as an efficient catalyst for hydrogenation of nitroarenes
Elhampour, Ali,Nanadegani, Zahra Soleimani,Nemati, Firouzeh,Rangraz, Yalda
, (2020/09/15)
Highly nitrogen-doped mesoporous carbon (N-mC) material incorporated cobalt oxide nanoparticles was synthesized through simple pyrolysis of environmentally friendly chitosan-polyaniline-Co(OAc)2 precursor in one-step. The as-prepared catalyst named CoO&at;N-mC with 14.65 ?wtpercent nitrogen content was characterized by different analysis techniques. The heterogeneous catalyst exhibits outstanding catalytic activity for the reduction of a variety of nitroaromatic compounds in the presence of NaBH4 as a reducing agent in water as a green solvent at 75 ?°C. Utilization of natural biological macromolecules such as chitosan as green and cheap starting material with harmless aniline and earth-abundant cobalt salt, facile synthesis, excellent product yield, short reaction time, high chemoselectivity, sustainable and mild reaction condition, and reusability of catalyst for at least five cycles without any significant decline in the catalytic efficiency are some prominent merits of this new nanocatalyst.
Pd-Co catalysts prepared from palladium-doped cobalt titanate precursors for chemoselective hydrogenation of halonitroarenes
Bustamante, Tatiana M.,Dinamarca, Robinson,Torres, Cecilia C.,Pecchi, Gina,Campos, Cristian H.
, (2019/12/24)
Bimetallic Pd-Co catalysts supported on the mixed oxides CoTiO3-CoO-TiO2 (CTO) were synthesized via the thermal reduction of Pd-doped cobalt titanates PdxCo1-xTiO3 and evaluated for the chemoselective hydrogenation of halonitroarenes to haloarene-amines. The nominal Pd mass percentage of the Pd-Co/CTO systems was varied from 0.0 to 0.50. After the thermal reduction of PdxCo1-xTiO3 at 500 °C for 3 h, Pd was completely reduced and Co was partially reduced, producing a mixture of ionic Co, metallic Co, and TiO2-rutile species to give the supported bimetallic catalysts. The metallic cobalt content increased with the Pd content of the precursor. The catalytic activity toward 4-chloronitrobenzene increased with the Pd content; however, >0.1 mass% Pd decreased the chemoselectivity toward 4-chloroaniline due to the formation of the hydrodehalogenation product—aniline. The 0.1Pd-Co/CTO system was used as a model catalyst to produce haloarene-amine building blocks for linezolid, loxapine, lapatinib, and sorafenib with >98% conversion, 96% chemoselectivity, and no hydrohalogenation products. Finally, recycling tests of the 0.1Pd-Co/CTO catalyst showed loss of activity and selectivity during the third cycle due to catalyst deactivation. Regeneration treatments, every two catalytic cycles, allowed six operation cycles without loss of chemoselectivity and only a slight decrease in catalytic activity during the last cycle.
Promotional effect of palladium in Co-SiO2 core@shell nanocatalysts for selective liquid phase hydrogenation of chloronitroarenes
Bustamante, Tatiana M.,Campos, Cristian H.,Fraga, Marco A.,Fierro,Pecchi, Gina
, p. 224 - 237 (2020/04/08)
This study describes the synthesis of palladium-promoted Co@SiO2 catalyst developed by electrostatic immobilization of Pd ionic precursor onto Co3O4 nanoparticles core, coated with a mesoporous SiO2 shell. The oxidized Pd-Co3O4@SiO2 (xPdCo-ox) and partially reduced Pd-Co@SiO2 (xPdCo-red) nanocatalysts were used in the direct synthesis of chloro-arylamines from chloronitroarenes employing heterogeneous hydrogenation process. The effect of palladium content (xPdCo; x = 0.0, 0.5, 1.0 and 3.0 Pd wt%) in the Co3O4 core of the structures on catalytic performance for the hydrogenation of 4-chloronitrobenzene (CNB) to 4-chloroaniline (CAN) was systematically studied. It was found that the incorporation of palladium ionic precursor promotes both Co3O4 core nanoparticles flocculation and an increase in the mesoporous shell thickness in the Pd-promoted catalysts compared to the pristine Co-SiO2 core-shell structure. The TPR, XRD, XPS and magnetic measurements results indicated that the palladium addition promoted the reduction of Co3O4 core during the isothermal H2 treatment at 873 K rendering metallic Pd° and Co° species. The catalytic CNB hydrogenation experiments showed that the 0.5PdCo-red catalyst inhibited both the hydrodechlorination and intermediates accumulation reaching 99% yield in CAN compared to 1.0PdCo-red and 3.0PdCo-red catalysts which provided aniline as undesired product. Additionally, the 0.5PdCo-red catalyst was easily recycled with a moderate catalytic activity after five consecutive reaction cycles. Finally, the catalytic hydrogenation performance of the 0.5PdCo-red catalyst for different pharmaceutical substituted chloro-nitroarenes such as 1-(4-chlorophenoxy)-2-nitrobenzene, 2-chloro-1-((3-fluorobenzyl)oxy)-4-nitrobenzene and 2-chloro-5nitrobenzotrifluoride was also evaluated and revealed high activity (>99% at 3 h of reaction) and selectivity towards the desired chloro-arylmines production, highlighting the potential of this catalyst in these processes.
