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All total 56 Articles be foundRegioselective C-H Thioarylation of Electron-Rich Arenes by Iron(III) Triflimide Catalysis
Dodds, Amy C.,Sutherland, Andrew
, p. 5922 - 5932 (2021/05/04)
A mild and regioselective method for the preparation of unsymmetrical biaryl sulfides using iron(III) catalysis is described. Activation of N-(arylthio)succinimides using the powerful Lewis acid iron(III) triflimide allowed the efficient thiolation of a range of arenes, including anisoles, phenols, acetanilides, and N-heterocycles. The method was applicable for the late-stage thiolation of tyrosine and tryptophan derivatives and was used as the key step for the synthesis of pharmaceutically relevant biaryl sulfur-containing compounds such as the antibiotic dapsone and the antidepressant vortioxetine. Kinetic studies revealed that while N-(arylthio)succinimides bearing electron-deficient arenes underwent thioarylation catalyzed entirely by iron(III) triflimide, N-(arylthio)succinimides with electron-rich arenes displayed an autocatalytic mechanism promoted by the Lewis basic product.
Preparation method of novel severe depression treatment drug
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Paragraph 0025; 0027; 0029-0031; 0036, (2021/10/30)
The invention provides a preparation method of novel medicament for treating severe depression, and belongs to the field of drug synthesis. A specific scheme of the invention is as follows: 2,4 - dimethyl thiophenol is used. 2 - Bromoiodobenzene, piperazine is a starting material, cuprous iodide is used as a catalyst, one-pot method is used for preparing the, and an organic base is added in the reaction system. To the preparation process, the reaction can be effectively carried out in a homogeneous phase, so that the reaction speed is obviously increased, and the product yield is greatly improved. The problem that in the prior art, homogeneous phase cannot be formed in a reaction system, the reaction time is over 40 hours, and the cost is not greatly reduced in industrial production is solved. Due to the adoption of triethylamine, N, N - diisopropylethylamine and other organic amines, the reaction can be carried out in a homogeneous phase, so that the secondary reaction is reduced, the yield and the purity are greatly improved. The piperazine does not need to be simultaneously added with the starting materials, the feeding step is optimized, the side reaction is reduced, the processes such as filtering are not increased, the procedures in industrialization are not increased, and the investment of equipment and the like is increased.
Study of the isomeric Maillard degradants, glycosylamine and Amadori rearrangement products, and their differentiation via MS2 fingerprinting from collision-induced decomposition of protonated ions
Wang, Shaolan,Lin, Jinsheng,Li, Dan,Huang, Tianpei,Zhu, Wenquan,Chen, Wenbin,Li, Min,Shen, Weiyang
, (2021/04/14)
Rationale: The focus of this work was to study glycosylamine and Amadori rearrangement products (ARPs), the two major degradants in the Maillard reactions of pharmaceutical interest, and utilize their MS2 fingerprints by liquid chromatography/high-resolution tandem mass spectrometry (LC/HRMS2) to quickly distinguish the two isomeric degradants. These two types of degradants are frequently encountered in the compatibility and stability studies of drug products containing primary or secondary amine active pharmaceutical ingredients (APIs), which are formulated with excipients consisting of reducing sugar functionalities. Methods: Vortioxetine was employed as the primary model compound to react with lactose to obtain the glycosylamine and ARP degradants of the Maillard reaction, and their MS2 spectra (MS2 fingerprints) were obtained by LC/MS2. Subsequently, the two degradants were isolated via preparative HPLC and their structures were confirmed by one- and two-dimensional (1D and 2D) nuclear magnetic resonance (NMR) determination. Results: The MS2 fingerprints of the two degradants display significantly different profiles, despite the fact that many common fragments are observed. Specifically, protonated glycosylamine shows a prominent characteristic fragment of [Mvort + C2H3O]+ at m/z 341 (Mvort is the vortioxetine core), while protonated ARP shows a prominent characteristic fragment of [Mvort + CH]+ at m/z 311. Further study of the Maillard reactions between several other structurally diverse primary/secondary amines and lactose produced similar patterns. Conclusions: The study suggests that the characteristic MS2 fragment peaks and their ratios may be used to differentiate the glycosylamine and ARP degradants, the two isomeric degradants of the Maillard reaction, which are commonly encountered in finished dosage forms of pharmaceutical products containing primary and secondary amine APIs.
