scholarly journals Multistep batch-flow hybrid synthesis of a terbinafine precursor

2021 ◽  
Author(s):  
Tamás Hergert ◽  
Béla Mátravölgyi ◽  
Róbert Örkényi ◽  
János Éles ◽  
Ferenc Faigl
Keyword(s):  
Methyl Ether ◽  
Lithium Salt ◽  
Scale Up ◽  
Hybrid Process ◽  
High Yield ◽  
Grignard Reaction ◽  
Efficient Synthesis ◽  
Synthetic Process ◽  
Synthesis Route ◽  
Selective Addition

AbstractA three-step batch-flow hybrid process has been developed for an expeditious synthesis of the enynol key intermediate of antifungal terbinafine. This procedure involves consecutive organometallic steps without the necessity of any in-line purification: after a metalation by n-butyllithium, a selective addition of the lithium salt was elaborated followed by a Grignard reaction resulting in a high yield of 6,6-dimethylhept-1-en-4-yn-3-ol. Moreover, as an alternative to tetrahydrofuran, cyclopentyl methyl ether was used as solvent implementing a safe, sustainable, yet selective synthetic process. Even on a laboratory-scale, the optimized batch-flow hybrid process had a theoretical throughput of 41 g/h. Furthermore, the newly developed process provides an efficient synthesis route to the key-intermediate, while making acrolein obsolete, minimizing side-products, and enabling safe and convenient scale-up.

scholarly journals A Facile Synthesis of 3-(Chloromethyl)-2-methyl-1,1′-biphenyl

2019 ◽  
Vol 31 (12) ◽  
pp. 3009-3011
Author(s):  
Lele Zhang ◽  
Songbo Cheng ◽  
Hang Hu ◽  
Defeng Xu
Keyword(s):  
High Risk ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
High Yield ◽  
Synthesis Process ◽  
Lithium Aluminum ◽  
Efficient Synthesis ◽  
Facile Synthesis ◽  
Synthetic Process ◽  
Safety Issues

3-(Chloromethyl)-2-methyl-1,1′-biphenyl is a key intermediate for the preparation of bifenthrin, an insecticide which belongs to pyrethroid. The traditional synthetic process of 3-(chloromethyl)-2-methyl- 1,1′-biphenyl is complicated and involves high-toxic and high-risk reagents such as thionyl chloride, lithium aluminum hydride and methyl iodide, which causes significant environmental problems and safety issues. Herein, a facile and efficient synthesis process of 3-(chloromethyl)-2- methyl-1,1′-biphenyl was developed. The synthetic process is shortened from 6 steps to only 4 steps and avoids the use of high-toxic and high-risk reagents. Moreover, 3-(chloromethyl)-2-methyl-1,1′-biphenyl can be obtained by simple purification process in high yield (73.9 %). Compared with the traditional synthetic process, the synthetic process of 3-(chloromethyl)-2-methyl-1,1′-biphenyl reported here is more environmental friendly and efficient.

scholarly journals β-Ketophosphonates with Pentalenofuran Scaffolds Linked to the Ketone Group for the Synthesis of Prostaglandin Analogs

2021 ◽  
Vol 22 (13) ◽  
pp. 6787
Author(s):  
Constantin I. Tănase ◽  
Constantin Drăghici ◽  
Miron Teodor Căproiu ◽  
Anamaria Hanganu ◽  
Gheorghe Borodi ◽  
...  
Keyword(s):  
Lithium Salt ◽  
Methyl Esters ◽  
Secondary Compounds ◽  
Molecular Structures ◽  
Keto Group ◽  
High Yield ◽  
Oxidation Reactions ◽  
Prostaglandin Analogues ◽  
X Ray ◽  
Oxidation Of Alcohols

β-Ketophosphonates with pentalenofurane fragments linked to the keto group were synthesized. The bulky pentalenofurane skeleton is expected to introduce more hindrance in the prostaglandin analogues of type III, greater than that obtained with the bicyclo[3.3.0]oct(a)ene fragments of prostaglandin analogues I and II, to slow down (retard) the inactivation of the prostaglandin analogues by oxidation of 15α-OH to the 15-keto group via the 15-PGDH pathway. Their synthesis was performed by a sequence of three high yield reactions, starting from the pentalenofurane alcohols 2, oxidation of alcohols to acids 3, esterification of acids 3 to methyl esters 4 and reaction of the esters 4 with lithium salt of dimethyl methanephosphonate at low temperature. The secondary compounds 6b and 6c were formed in small amounts in the oxidation reactions of 2b and 2c, and the NMR spectroscopy showed that their structure is that of an ester of the acid with the starting alcohol. Their molecular structures were confirmed by single crystal X-ray determination method for 6c and XRPD powder method for 6b.

Enantioselective synthesis of (R)-tolterodine using lithiation/borylation–protodeboronation methodology

2012 ◽  
Vol 90 (11) ◽  
pp. 965-974 ◽  
Author(s):  
Stefan Roesner ◽  
Varinder K. Aggarwal
Keyword(s):  
Enantioselective Synthesis ◽  
High Yield ◽  
Magnesium Bromide ◽  
Efficient Synthesis ◽  
Boronic Ester ◽  
Better Than

The synthesis of the pharmaceutical (R)-tolterodine is reported using lithiation/borylation–protodeboronation of a homoallyl carbamate as the key step. This step was tested with two permutations: an electron-neutral aryl Li-carbamate reacting with an electron-rich boronic ester and an electron-rich aryl Li-carbamate reacting with an electron-neutral boronic ester. It was found that the latter arrangement was considerably better than the former. Further improvements were achieved using magnesium bromide in methanol leading to a process that gave high yield and high enantioselectivity in the lithiation/borylation reaction. The key step was used in an efficient synthesis of (R)-tolterodine in a total of eight steps in a 30% overall yield and 90% ee.

ChemInform Abstract: A NEW EFFICIENT SYNTHESIS OF IODOMETHYL METHYL ETHER

1978 ◽  
Vol 9 (50) ◽  
Author(s):  
M. E. JUNG ◽  
M. A. MAZUREK ◽  
R. M. LIM
Keyword(s):  
Methyl Ether ◽  
Efficient Synthesis

scholarly journals Synthesis of deoxymannojirimycin using a Ruthenium-catalysed hydrogen borrowing reaction

2021 ◽  
Author(s):  
◽  
Victoria Skinner
Keyword(s):  
Scale Up ◽  
Ruthenium Catalyst ◽  
High Yield ◽  
One Pot ◽  
Unfolded Protein ◽  
Unit Operations ◽  
Hepatocarcinoma Cells ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Reaction Vessels

<p>1-Deoxymannojirimycin (DMJ) has been investigated as a potential anti-cancer therapy due to its specific inhibition of class I α-mannosidase enzymes, which has been shown to trigger ER stress and the Unfolded Protein Response (UPR) pathway, leading to apoptosis in human hepatocarcinoma cells. Current methods for the synthesis of DMJ consist of multiple steps and often result in poor yields. The objectives of this research project were to develop a scale-up suitable synthesis of deoxymannojirimycin (DMJ), and to assess the feasibility of telescoping key-reactions to reduce the number of unit operations. Synthetic efforts focused on the key conversion of 1 to 2 have previously involved separate oxidation and reduction steps. In our laboratory; attempts to use hydrogen-borrowing chemistry had taken >48hr and not been achieved in high yield. The highlights of this work were that this conversion was ultimately realised in 95% yield in 24hr, and that the final deprotection of (2) could be telescoped into the process removing reaction-workup and chromatographic steps. The ruthenium catalyst used in the hydrogen borrowing reaction was found to be extremely air-sensitive, with reactions taking place in carefully prepared reaction vessels under an atmosphere of dry argon gas. The catalyst was also found to exhibit sensitivities to materials such as metal needles and polymer tubing, preventing sampling and monitoring of the reaction during synthesis. This study demonstrated that a one-pot synthesis is feasible,compressing the final steps in the synthesis of DMJ in excellent yield. The difficulty arises from the sensitive nature of the ruthenium catalyst, and the extreme care required in the preparation of the glassware and reagents used in synthesis. Many aspects of this development require further investigation, including the sampling, monitoring and quality control of each synthetic step.</p>

scholarly journals Synthesis of deoxymannojirimycin using a Ruthenium-catalysed hydrogen borrowing reaction

2021 ◽  
Author(s):  
◽  
Victoria Skinner
Keyword(s):  
Scale Up ◽  
Ruthenium Catalyst ◽  
High Yield ◽  
One Pot ◽  
Unfolded Protein ◽  
Unit Operations ◽  
Hepatocarcinoma Cells ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Reaction Vessels

<p>1-Deoxymannojirimycin (DMJ) has been investigated as a potential anti-cancer therapy due to its specific inhibition of class I α-mannosidase enzymes, which has been shown to trigger ER stress and the Unfolded Protein Response (UPR) pathway, leading to apoptosis in human hepatocarcinoma cells. Current methods for the synthesis of DMJ consist of multiple steps and often result in poor yields. The objectives of this research project were to develop a scale-up suitable synthesis of deoxymannojirimycin (DMJ), and to assess the feasibility of telescoping key-reactions to reduce the number of unit operations. Synthetic efforts focused on the key conversion of 1 to 2 have previously involved separate oxidation and reduction steps. In our laboratory; attempts to use hydrogen-borrowing chemistry had taken >48hr and not been achieved in high yield. The highlights of this work were that this conversion was ultimately realised in 95% yield in 24hr, and that the final deprotection of (2) could be telescoped into the process removing reaction-workup and chromatographic steps. The ruthenium catalyst used in the hydrogen borrowing reaction was found to be extremely air-sensitive, with reactions taking place in carefully prepared reaction vessels under an atmosphere of dry argon gas. The catalyst was also found to exhibit sensitivities to materials such as metal needles and polymer tubing, preventing sampling and monitoring of the reaction during synthesis. This study demonstrated that a one-pot synthesis is feasible,compressing the final steps in the synthesis of DMJ in excellent yield. The difficulty arises from the sensitive nature of the ruthenium catalyst, and the extreme care required in the preparation of the glassware and reagents used in synthesis. Many aspects of this development require further investigation, including the sampling, monitoring and quality control of each synthetic step.</p>

scholarly journals Pushing Nanomaterials past the Kilogram Scale—a Targeted Approach Integrating Scalable Microreactors, Machine Learning and High-Throughput Analysis

2020 ◽  
Author(s):  
Nicholas Jose ◽  
mikhail Kovalev ◽  
Eric Bradford ◽  
Artur Schweidtmann ◽  
Hua Chun Zeng ◽  
...  
Keyword(s):  
Machine Learning ◽  
High Throughput ◽  
Scale Up ◽  
Process Efficiency ◽  
High Yield ◽  
Synthesis Methods ◽  
High Throughput Analysis ◽  
Throughput Analysis ◽  
Highly Active ◽  
Technological Advances

Novel materials are the backbone of major technological advances. However, the development and wide-scale introduction of new materials, such as nanomaterials, is limited by three main factors—the expense of experiments, inefficiency of synthesis methods and complexity of scale-up. Reaching the kilogram scale is a hurdle that takes years of effort for many nanomaterials. We introduce an improved methodology for materials development, combining state-of-the-art techniques—multi-objective machine learning optimization, high yield microreactors and high throughput analysis. We demonstrate this approach by efficiently developing a kg per day reaction process for highly active antibacterial ZnO nanoparticles. The proposed method has the potential to significantly reduce experimental costs, increase process efficiency and enhance material performance, which culminate to form a new pathway for materials discovery.

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