93413-69-5Relevant articles and documents
Room-temperature Pd-catalyzed methoxycarbonylation of terminal alkynes with high branched selectivity enabled by bisphosphine-picolinamide ligand
Chen, Fen-Er,Ke, Miaolin,Liu, Ding,Ning, Yingtang,Ru, Tong
, p. 1041 - 1044 (2022/01/28)
We report the room-temperature Pd-catalyzed methoxy-carbonylation with high branched selectivity using a new class of bisphosphine-picolinamide ligands. Systematic optimization of ligand structures and reaction conditions revealed the significance of both
The total synthesis of (-) -strempeliopine: Via palladium-catalyzed decarboxylative asymmetric allylic alkylation
An, Yi,Chen, Fener,Li, Weijian,Li, Yaling,Tang, Pei,Wang, Zhenzhen,Wu, Mengjuan,Xue, Yansong
, p. 1402 - 1405 (2022/02/09)
In the work reported herein, the concise and enantioselective total synthesis of the Schizozygine alkaloid (-)-strempeliopine was developed. This synthetic strategy featured the palladium-catalyzed decarboxylative asymmetric allylic alkylation of N-benzoy
Simple RuCl3-catalyzed N-Methylation of Amines and Transfer Hydrogenation of Nitroarenes using Methanol
Sarki, Naina,Goyal, Vishakha,Tyagi, Nitin Kumar,Puttaswamy,Narani, Anand,Ray, Anjan,Natte, Kishore
, p. 1722 - 1729 (2021/04/19)
Methanol is a potential hydrogen source and C1 synthon, which finds interesting applications in both chemical synthesis and energy technologies. The effective utilization of this simple alcohol in organic synthesis is of central importance and attracts scientific interest. Herein, we report a clean and cost-competitive method with the use of methanol as both C1 synthon and H2 source for selective N-methylation of amines by employing relatively cheap RuCl3.xH2O as a ligand-free catalyst. This readily available catalyst tolerates various amines comprising electron-deficient and electron-donating groups and allows them to transform into corresponding N-methylated products in moderate to excellent yields. In addition, few marketed pharmaceutical agents (e. g., venlafaxine and imipramine) were also successfully synthesized via late-stage functionalization from readily available feedstock chemicals, highlighting synthetic value of this advanced N-methylation reaction. Using this platform, we also attempted tandem reactions with selected nitroarenes to convert them into corresponding N-methylated amines using MeOH under H2-free conditions including transfer hydrogenation of nitroarenes-to-anilines and prepared drug molecules (e. g., benzocaine and butamben) as well as key pharmaceutical intermediates. We further enable one-shot selective and green syntheses of 1-methylbenzimidazole using ortho-phenylenediamine (OPDA) and methanol as coupling partners.
Amino alcohols using the optically active amino alcohol derivative bi- Nord complex boron - -
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Paragraph 0064; 0071-0076; 0281-0283; 0285-0286, (2021/04/16)
Disclosed are an amino alcohol-boron-binol complex as an intermediate, including Complex 3-1-1 shown below, and a method for preparing an optically active amino alcohol by using the same, wherein a racemic amino alcohol is resolved in an enationselective manner using a boron compound and a (R)- or (S)-binol, whereby an amino alcohol derivative with high optical purity can be prepared at high yield.
Method for synthesizing venlafaxine by utilizing fixed bed hydrogenation equipment
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Paragraph 0031-0090, (2021/06/09)
The invention discloses a method for synthesizing venlafaxine by using fixed bed hydrogenation equipment, which comprises the following step: weighing methoxybenzyl cyanide and cyclohexanone as raw materials, and preparing an intermediate 1 under the action of sodium hydroxide. According to the method for synthesizing venlafaxine by using the fixed bed hydrogenation equipment, sodium hydroxide is used as alkali to produce the intermediate 1, so that ultra-low temperature and use of an active reagent are avoided, the production technical difficulty is reduced, a filled supported precious metal catalyst is adopted to carry out catalytic hydrogenation reaction, the intermediate 1 and hydrogen carry out reduction under the action of a catalyst loaded on one ore more of rhodium, palladium, and nickel, a cyan group of the intermediate 1 molecule is reduced into an amino group,venlafaxine is synthesized through fixed bed hydrogenation equipment, a supported catalyst is filled into a stainless steel reaction tube of the fixed bed hydrogenation equipment, the reactions can be carried out continuously, and the method has the characteristics of small reaction volume, large yield, safe production, and low production cost.
Bisguanidinium-Catalyzed Epoxidation of Allylic and Homoallylic Amines under Phase Transfer Conditions
Chin, Kek Foo,Kabylda, Adil M.,Lee, Richmond,Leow, Dasheng,Li, Yongxin,Tan, Choon-Hong,Xia Ang, Esther Cai,Ye, Xinyi,Zhang, Xin
, p. 2684 - 2691 (2020/03/11)
A highly enantioselective epoxidation reaction of allylic and homoallylic amines has been disclosed using an ion pair catalyst, which consists of chiral cationic bisguanidinium [BG]2+ and an achiral tetraperoxyditungstate anion [W2O2(μ-O)(O2)4]2-. The terminal oxidant is a stoichiometric amount of aqueous hydrogen peroxide, an environmentally benign reagent. Up to 96% enantiomeric excess and 99% yields were achieved for 1,1′-disubstituted and 1,2-disubstituted allylic protected amines and 1,2-disubstituted homoallylic protected amines. The identity of the ion pair catalyst was uncovered using X-ray crystallography and revealed that the achiral tetraperoxyditungstate anion species [W2O2(μ-O)(O2)4]2- is nudged nicely into the central cavity of the chiral dication. The ion pair catalyst was also characterized using infrared (IR) and Raman spectroscopies. The synthesis of (-)-venlafaxine was achieved via this reported methodology to demonstrate its usefulness.
Enantioseparation of chiral pharmaceuticals by vancomycin-bonded stationary phase and analysis of chiral recognition mechanism
Li, Jiaxi,Liu, Ruixia,Wang, Liyang,Liu, Xiaoling,Gao, Hongjie
, p. 236 - 247 (2019/02/01)
The drug chirality is attracting increasing attention because of different biological activities, metabolic pathways, and toxicities of chiral enantiomers. The chiral separation has been a great challenge. Optimized high-performance liquid chromatography (HPLC) methods based on vancomycin chiral stationary phase (CSP) were developed for the enantioseparation of propranolol, atenolol, metoprolol, venlafaxine, fluoxetine, and amlodipine. The retention and enantioseparation properties of these analytes were investigated in the variety of mobile phase additives, flow rate, and column temperature. As a result, the optimal chromatographic condition was achieved using methanol as a main mobile phase with triethylamine (TEA) and glacial acetic acid (HOAc) added as modifiers in a volume ratio of 0.01% at a flow rate of 0.3?mL/minute and at a column temperature of 5°C. The thermodynamic parameters (eg, ΔH, ΔΔH, and ΔΔS) from linear van 't Hoff plots revealed that the retention of investigated pharmaceuticals on vancomycin CSP was an exothermic process. The nonlinear behavior of lnk′ against 1/T for propranolol, atenolol, and metoprolol suggested the presence of multiple binding mechanisms for these analytes on CSP with variation of temperature. The simulated interaction processes between vancomycin and pharmaceutical enantiomers using molecular docking technique and binding energy calculations indicated that the calculated magnitudes of steady combination energy (ΔG) coincided with experimental elution order for most of these enantiomers.
Preparation method of demethylvenlafaxine succinate compound
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Paragraph 0027; 0045; 0046; 0049, (2019/05/02)
The invention discloses a preparation method of a demethylvenlafaxine succinate compound. The preparation method is characterized in that 1-[2-amino-1-(4-methoxyphenyl)ethyl] cyclohexanol hydrochloride is taken as an initial material to prepare a demethylvenlafaxine succinate compound finished product with high purity by virtue of two-step reaction of methylation and demethylation as well as the reaction with succinic acid in a mixed solvent of acetone-water. The improved process is high in yield, low in cost, easy in operation and beneficial to the industrialized production.
A method for preparing venlafaxine hydrochloride (by machine translation)
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Paragraph 0036; 0037; 0039; 0040; 0042; 0043, (2019/04/10)
The invention provides a preparation method of venlafaxine hydrochloride, comprises the following steps: in the borohydride and of Lewis acids in reduction system under I compound formula II compound suitcase; the formula II compound acid formation to get to the venlafaxine hydrochloride; according to the present invention provides a preparation method of venlafaxine hydrochloride, the reaction process is safe, easy to control, and the cost is low, the ideal result, is suitable for industrial production. (by machine translation)
Efficient resolution of venlafaxine and mechanism study via X-ray crystallography
Liu, Zhi-Jin,Liu, Han,Chen, Xuan-Wen,Lin, Min,Hu, Yu,Tuo, Xun,Yuan, Zhong-Yi,Sun, Xiao-Xia
, p. 268 - 274 (2018/02/19)
Numbers of resolving factors were investigated to improve resolution of venlafaxine 1. An effective resolving agent, O,O′-di-p-toluoyl-(R, R)-tartaric acid 2, was screened using similar method of ‘Dutch resolution’ from tartaric acid derivatives. The resolution efficiency was up to 88.4%, when the ratio of rac-1 and 2 was 1:0.8 in THF with little water (10:1?v/v). Enantiomerically pure venlafaxine was prepared with 99.1% ee in 82.2% yield. The chiral resolution mechanism was first explained through X-ray crystallographic study. One diastereomeric salt with well solubility forms a columnar supramolecular structure as the acidic salt (R)-1·2, while the other diastereomeric salt with less solubility forms a multilayered sandwich supramolecular structure by enantio-differentiation self-assembly as the neutral salt 2(S)-1·2. The water molecules play a key role in the optical resolution, as indicated by the special structures of the diastereomeric salts.
