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.
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.
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.
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.