scholarly journals Synthesis of 11-(Piperazin-1-yl)-5H-dibenzo[b,e] [1,4]diazepine on Kilo Scale

2011 ◽  
Vol 8 (4) ◽  
pp. 1747-1749 ◽  
Author(s):  
Rahul S. Kalhapure ◽  
Bhushan P. Patil ◽  
Mahantesh N. Jadhav ◽  
Laxmikant A. Kawle ◽  
Sanjay B. Wagh
Keyword(s):  
Catalytic Hydrogenation ◽  
Chromatographic Purification ◽  
Purification Step ◽  
Key Steps

A synthesis of 11-(piperazin-1yl)-5 H-dibenzo[b,e][1,4]diazepine on kilo scale without any chromatographic purification step is reported. Key steps involved are Ullmann condensation, catalytic hydrogenation, and catalyzed cyclization.

scholarly journals Preparation and Validated Analysis of Anthocyanin Concentrate from the Calyces of Hibiscus sabdariffa

2017 ◽  
Vol 12 (1) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Lubomir Opletal ◽  
Lucie Chocholousova-Havlikova ◽  
Tomas Siatka ◽  
Lucie Cahliková ◽  
Miroslav Locarek ◽  
...  
Keyword(s):  
Analytical Method ◽  
Anthocyanin Content ◽  
Hibiscus Sabdariffa ◽  
Chromatographic Purification ◽  
Purification Step ◽  
Extraction And Purification ◽  
Medicinal Properties ◽  
The Individual ◽  
Method Of Extraction ◽  
Column Chromatographic

Extracts of Hibiscus sabdariffa calyces have been shown to have various medicinal properties, some of which have been reported to be due to anthocyanins present in the calyces. To study whether these claims are valid, it is necessary to produce an extract with a high anthocyanin content and to have available a method to identify and quantify the individual compounds in the product. A method of extraction and purification has been developed based on a polyamide column chromatographic purification step. Using this method, anthocyanin concentrates were produced containing from 57 to 64% of delphinidin-3-sambubioside plus cyanidin-3-sambubioside. A rapid, efficient and validated HPLC analytical method was developed and used for the analysis of the anthocyanin concentrate.

Exploratory synthetic investigations related to 12a-deoxypillaromycinone

2002 ◽  
Vol 80 (6) ◽  
pp. 728-738 ◽  
Author(s):  
Lan Wang ◽  
Sanath K Meegalla ◽  
Cheng-Lin Fang ◽  
Nicholas Taylor ◽  
Russell Rodrigo
Keyword(s):  
Double Bond ◽  
Catalytic Hydrogenation ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Step Procedure ◽  
Key Steps

Furfural is converted to suitably substituted AB synthon 21 for 12a-deoxypillaromycinone in 10 steps by a sequence involving the following key steps: intramolecular Diels-Alder reaction of a furan, 5-endo-trig cleavage of the oxabicyclo adducts 18, and catalytic hydrogenation of the double bond of a tetrasubstituted enone to produce 19. Enones 21a and 21b obtained by dehydrogenation of 19a and 19b, respectively, are then annulated with ethyl 2-methoxy-6-methylbenzoate in a four-step procedure to generate tetracyclic products 25 in 14 steps from furfural.

Stereospecific Synthesis of (+)-Muscarine from D-Glucose, Suitable for Preparation of 5-Substituted Analogues

1998 ◽  
Vol 63 (10) ◽  
pp. 1522-1527 ◽  
Author(s):  
Velimir Popsavin ◽  
Ostoja Beric ◽  
Ljubica Radic ◽  
Mirjana Popsavin ◽  
Vera Cirin-Novta ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Mitsunobu Reaction ◽  
Stereospecific Synthesis ◽  
Key Steps ◽  
Stereospecific Cyclization

A stereospecific synthesis of (+)-muscarine iodide (1) has been achieved starting from D-glucose as a chiral precursor. The key steps of the synthesis involved a stereospecific cyclization of 3,5-di-O-mesyl derivative 3 into the 2,5-anhydride 4, the stereospecific catalytic hydrogenation of unsaturated derivative 6, and the C-4 epimerization of alcohol 12 by Mitsunobu reaction.

scholarly journals A releasable disulfide-linked peptide tag facilitates the synthesis and purification of short peptides

2020 ◽  
Vol 56 (19) ◽  
pp. 2917-2920 ◽  
Author(s):  
Yuteng Wu ◽  
Alessandro Zorzi ◽  
Jack Williams ◽  
Christian Heinis
Keyword(s):  
Peptide Synthesis ◽  
Macrocyclic Compound ◽  
Short Peptides ◽  
Chromatographic Purification ◽  
Purification Step ◽  
Compound Libraries ◽  
Peptide Tag

A peptide synthesis and purification strategy that omits a throughput-limiting chromatographic purification step offers access to large macrocyclic compound libraries.

A two-hour synthesis of anti-Parkinson drug Safinamide Methanesulfonate

Synlett ◽  
2021 ◽  
Author(s):  
Vanessa Mayumi Higa ◽  
Alvaro Takeo Omori
Keyword(s):  
Microwave Irradiation ◽  
Ethyl Acetate ◽  
Real Time ◽  
Therapeutic Agents ◽  
Biologically Active ◽  
Green Solvents ◽  
Free Base ◽  
Chromatographic Purification ◽  
Purification Step ◽  
One Pot

The critical moment of COVID-19 outbreak requires a real time supply of therapeutic agents. Thus, the time economy in the synthesis of biologically active compounds has been increasingly decisive. In this work, we have developed a two-hour synthesis of anti-Parkinson drug safinamide methanesulfonate in 4 steps, with 64% overall yield. Microwave irradiation was used in the first three steps in a one-pot fashion. In fact, this presented protocol can provide Safinamide free base in one hour without chromatographic purification step. Also, green solvents such as methanol and ethyl acetate were applied.

Reflections on the Cognitive Interviewing Reporting Framework

Methodology ◽  
2013 ◽  
Vol 9 (3) ◽  
pp. 123-128 ◽  
Author(s):  
Gordon Willis ◽  
Hennie Boeije
Keyword(s):  
Research Design ◽  
Cognitive Testing ◽  
Level Of Detail ◽  
Cognitive Interviewing ◽  
Research Groups ◽  
Research Project ◽  
Reporting Framework ◽  
Full Explanation ◽  
Key Steps

Based on the experiences of three research groups using and evaluating the Cognitive Interviewing Reporting Framework (CIRF), we draw conclusions about the utility of the CIRF as a guide to creating cognitive testing reports. Authors generally found the CIRF checklist to be usable, and that it led to a more complete description of key steps involved. However, despite the explicit direction by the CIRF to include a full explanation of major steps and features (e.g., research objectives and research design), the three cognitive testing reports tended to simply state what was done, without further justification. Authors varied in their judgments concerning whether the CIRF requires the appropriate level of detail. Overall, we believe that current cognitive interviewing practice will benefit from including, within cognitive testing reports, the 10 categories of information specified by the CIRF. Future use of the CIRF may serve to direct the overall research project from the start, and to further the goal of evaluation of specific cognitive interviewing procedures.

The development of alternative energy sources: Prospects in Russia and the world

2020 ◽  
Vol 16 (5) ◽  
pp. 885-904
Author(s):  
M.E. Frai
Keyword(s):  
Alternative Energy ◽  
Systems Approach ◽  
Energy Resource ◽  
Current Situation ◽  
Energy Sources ◽  
The Sustainable Development ◽  
Energy Complex ◽  
Alternative Energy Sources ◽  
Governmental Institutions ◽  
Key Steps

Subject. The article discusses limited sources of energy nowadays and an ongoing survey of new ones. I focus on fuel and energy complexes worldwide and in Russia. Objectives. The study is to analyze the future use of alternative energy sources in the fuel and energy complex nationwide and worldwide. I review the existing energy sources of the fuel and energy complex in the global and regional markets, specifically the alternative ones. Methods. The study relies upon methods of statistics, analysis and systems approach. Results. The article demonstrates that the fuel and energy complex strongly depends on the current situation in the energy resource market, which is difficult to forecast. If we continue relying on traditional energy resources, we get exposed to some risks affecting the sustainable development of the economy. Russia should diversify the power engineering sector by developing alternative energy sources. The article sets forth the economic rationale for alternative sources and key steps Russia shall make. Conclusions and Relevance. Considering the current situation in the energy balance, alternative energy is what any advanced society seeks for, being supported by manufacturers, governmental institutions, and researchers, though low profitability and high infrastructure costs impede its development. In Russia, these challenges are even more palpable. However, even now Russia is able to find alternative energy solutions. In addition to advantages of alternative energy, which is globally proclaimed, they will also help Russia diversify and update the economic system.

Nanometer Scale Spectroscopic Visualization of Catalytic Sites During a Hydrogenation Reaction on a Pd/Au Bimetallic Catalyst

2020 ◽  
Author(s):  
hao yin ◽  
Liqing Zheng ◽  
Wei Fang ◽  
Yin-Hung Lai ◽  
Nikolaus Porenta ◽  
...  
Keyword(s):  
Catalytic Hydrogenation ◽  
Density Functional ◽  
Hydrogen Transfer ◽  
Bimetallic Catalyst ◽  
Local Environment ◽  
Hydrogenation Reaction ◽  
Boundary Density ◽  
Catalytic Sites ◽  
Powerful Analytical Tool ◽  
Tip Enhanced Raman Spectroscopy

<p>Understanding the mechanism of catalytic hydrogenation at the local environment requires chemical and topographic information involving catalytic sites, active hydrogen species and their spatial distribution. Here, tip-enhanced Raman spectroscopy (TERS) was employed to study the catalytic hydrogenation of chloro-nitrobenzenethiol on a well-defined Pd(sub-monolayer)/Au(111) bimetallic catalyst (<i>p</i><sub>H2</sub>=1.5 bar, 298 K), where the surface topography and chemical fingerprint information were simultaneously mapped with nanoscale resolution (≈10 nm). TERS imaging of the surface after catalytic hydrogenation confirms that the reaction occurs beyond the location of Pd sites. The results demonstrate that hydrogen spillover accelerates hydrogenation at the Au sites within 20 nm from the bimetallic Pd/Au boundary. Density functional theory was used to elucidate the thermodynamics of interfacial hydrogen transfer. We demonstrate that TERS as a powerful analytical tool provides a unique approach to spatially investigate the local structure-reactivity relationship in catalysis.</p>

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