Organic Synthesis Laboratory Research Articles

Cover Feature: Visible Light‐Triggered Radical Annulation of ortho‐Thioaryl Ynones: A General Approach to Prepare 3‐Sulfenylthiochromones (ChemCatChem 7/2023)

The Cover Feature shows the office environment of an organic synthesis laboratory, centered around a “synthetic tools desk,” which is a place where ideas are discussed on a daily basis. In their Research Article, R. H. Bartz et al. demonstrated one of the few cases in which an intramolecular EDA-complex (the molecule on the desk) is used as a species that can absorb blue light (440 nm) and trigger an annulative radical process. In this sophisticated synthetic transformation, thiols are used as reactants, giving rise to the “most wanted” 3-sulfenylthiochromones. This strategy circumvents the classical use of photocatalytic species in light-mediated reactions, as well as the use of oxidants and heating, readily yielding the desired products in a short reaction time. Taken together, the main features of the developed approach meet some principles of green chemistry and promote sustainable chemistry. More information can be found in the Research Article by R. H. Bartz et al..

UJI EFEKTIFITAS EKSTRAK KULIT KULIM (Scorodocarpus borneensis Becc) SEBAGAI REPELLENT ANTI NYAMUK

The use of Scorodocarpus borneensis Becc as wood causes its availability in nature to decrease. An alternative step to utilize and maintain the availability of Kulim in nature is to utilize Scorodocarpus borneensis Becc’s bark extract. The bioactive substances and scent of Scorodocarpus borneensis Becc are considered capable of repelling insects and replacing DEET in chemical mosquito repellent raw materials. The use of Kulim wood extract is considered to be far better than the use of chemicals that can affect human health. This research was conducted in three laboratories, namely the forestry laboratory, organic chemistry laboratory and natural synthesis and chemical engineering laboratory. The parameters to know the quality of the extract from the bark of the Scorodocarpus borneensis Becc’s branch were yield observation, color observation, odor test and skin sensitivity, phytochemical test and the extract effectiveness test against mosquitoes which were expected to be in accordance with the criteria of the pesticide commission of the Department of Agriculture in 1995. The results showed that the yield from Scorodocarpus borneensis Becc’s wood extract was found to be worth 0.83%, the color of the extract was brown because it used water solvent, the distinctive aroma of the Scorodocarpus borneensis Becc was not found in the extract because it was dominated by tannins and the extract felt warm on the skin, phytochemical tests showed that the kulim extract contained substances such as saponins, phenolic, steroids and tannins as well as the effectiveness test of the extract against mosquitoes found a protection result of 44% which has not been able to meet the standard of repellent protection criteria from the Pesticide Commission of the Department of Agriculture in 1995.

Lessons Learned from Laboratory Vacuum Pump Exhaust Explosion: Discussion and Preventative Strategies

Here, we wish to report an explosion which occurred in an organic synthesis laboratory during an attempted evaporation of solvent via rotary evaporation. The explosion, which occurred inside of a vacuum pump cabinet, resulted in a fire and damages to the laboratory but no injuries. This “Lessons-Learned” article describes the direct cause of the event as determined by the Office of Environmental Health and Radiation Safety and proposes casual factors that should be considered to prevent this incident from occurring in other laboratories.

Residual Solvent Signal of CDCl3 as a qNMR Internal Standard for Application in Organic Chemistry Laboratory

A nuclear magnetic resonance (NMR) spectrometer is a key instrument in the organic synthesis laboratory for structure determination, reaction control, and compound purity analysis. In addition to qualitative analysis, the application of NMR for quantitative analysis (qNMR) is gaining popularity. qNMR allows for simple quantification of crude product mixtures, determination of reaction yields, and purity of organic compounds. The determination of NMR yield requires the addition of an internal standard to each sample. Herein, we report a method where CDCl3 residual solvent signal is used as an internal standard for qNMR after quantification in the solvent batch. This method significantly simplifies sample preparation and allows straightforward recovery of the analyte by the simple evaporation of the NMR solvent. The accuracy of the method is comparable to qNMR with 1,3,5-trimethoxybenzene as an internal standard if the herein described guidelines are followed.

Innovative ways of suppression of fungal infections of plants:approaches, solutions, outlooks

In order to study the possibility of suppressing mycoses with fumigation pyrotechnic compositions, biologically active compositions were developed based on compounds synthesized according to original methods in the organic synthesis laboratory of the Federal State Scientific Institution "All-Russian Research Institute of Phytopathology", synthetic fungicides from the azole group, as well as natural antimycotics from the polyene group obtained by microbial fermentation of Streptomyces bacteria, followed by extraction of supernatants and preparative column chromatography of extracts. Pyrotechnic compositions of fumigation action were developed, including active substances of biologically active compositions (23 … 46%), oxidizer (22…56%), combustible substances (15…56%), flame arresters (14…34%), phlegmatizers (6…20%) and baking powder (4…8%). The stability of complexes of synthesized compounds with putative cellular targets: ergosterol; ergosterol-dependent membrane Na+/K+-ATPases; 14α-demethylases controlling the conversion of lanosterol to ergosterol; and squalene-monooxygenases catalyzing the synthesis of squalene–epoxidase, a lanosterol precursor, was studied using computer modeling methods in the B3LYP/DZP approximation using the ChemCraft and FireFly software package. It was found that the synthesized compounds with nitro groups in the molecule selectively coordinate with the Na+/K+-ATPase membrane enzyme site responsible for phosphorylation and binding to ATP. It is revealed that the nitrogen atom of synthesized benzoxazines selectively coordinates with the iron of Gemma 14α-demethylase, and the binding energy of the complex is significantly lower than the coordination energy of iron with the cysteine residue of the protein matrix of the enzyme. It was fixed that the synthesized compounds at a concentration of 16-500 mcg/ml have fungicidal activity against test cultures Fusauium graminearum, Alternarium alternata, Bipolaris soraciniana, comparable to the activity of comparison drugs phytolavin and previcur. It was fixed that the samples of pyrotechnic charges of fumigation action developed in the laboratory of organic synthesis of the Federal State Scientific Institution VNIIF have fungicidal activity against the phytopathogenic fungi F. graminearum, A. alternata, B. soraciniana with an effective action of 23 … 69% of the test cultures. For wheat affected by the tested crops, the effectiveness of pyrotechnic charges was in the range of 12 … 31% of the death of test crops. It is revealed that the fumigation method of plant mycosis suppression implemented in this work, integrated with modern methods of medical chemistry, organic synthesis and classical methods of chemical treatment, is an effective innovative solution and can be used in the development of food security strategies.

Synthesis of 1-Phenylthiourea: An Undergraduate Organic Chemistry Experiment Illustrating Carbonyl Transformations

The practical two-step synthesis of 1-phenylthiourea is reported here as an undergraduate experiment for the organic synthesis laboratory. The reactions involved in 1-phenylthiourea preparation are very useful didactic examples to illustrate concepts relating to carbonyl substitution and addition, the effect of pH on solubility of organic compounds, and many laboratory techniques, such as isolation, purification, and product analysis. The products were purified through precipitation, which involves changing the pH value, followed by recrystallization. The products were identified by melting point and infrared and NMR spectroscopy.

Teaching Practice of Organic Synthesis Laboratory Course Based on the Combination of Research and Systematicness

Teaching Practice of Organic Synthesis Laboratory Course Based on the Combination of Research and Systematicness

An idea to explore: A collaboration and cross training in an extended classroom-based undergraduate research experience between primarily undergraduate and research-intensive institutions.

Providing students with training in advanced laboratory skills is an essential part of scientific education. At the same time, engaging students in research is becoming equally important. Classroom-based undergraduate research experiences (CUREs) have emerged to fill this need, and can take many forms. In this article we describe reengineering an advanced organic synthesis laboratory at a primarily undergraduate institution into a CURE. This objective of this CURE is to provide small molecules relevant to an ongoing research program at a research-intensive institution. This new model cross trains students and provides a new structure for a CURE that could be adapted to other partnerships and institutions.

Investigation of The Analgesic and Anti-Inflammatory Activities of Launaea Nudicaulis From Southwest of Algeria

Lamia Salima Seddiki1, Nasser Belboukhari*1, Aminata ould el hadj khelil4, Mohd Roslan Sulaiman3, Mimouna Yakoubi1, Khaled Sekkoum1 and Abdelkarim Cheriti2 Author Affiliations 1Bioactive Molecules & Chiral Separation Laboratory, Algeria 2Phytochemistry and organic synthesis laboratory, Algeria 3Inflammatory and Pain Group, Faculty of Bioscience and Health, Malaysia 4Faculty of Science of Nature and Life, Algeria Received: November 13, 2019 | Published: November 21, 2019 Corresponding author: Nasser Belboukhari, Bioactive Molecules & Chiral Separation Laboratory. Fac exact sciences, University Tahri Mohamed, Bechar 08000, Algeria DOI: 10.26717/BJSTR.2019.23.003858

Flow Chemistry: Towards A More Sustainable Heterocyclic Synthesis

Flow Chemistry is a revolutionary field in Organic Chemistry. By changing the conventional methods and apparatus applied in the chemical synthesis, flow chemistry emerges as a game changer for organic synthesis laboratories, in both academia and industries. Considered as a sustainable practice, flow processes play an important role in the development of fine chemical products and in drug discovery development programs. This work aims to review the recent contributions on heterocyclic synthesis under continuous‐flow conditions, focusing in heterocycle ring formation and highlighting some of the most recent examples found in the literature, as well as some synthetic strategies aiming for the flow preparation of high‐value chemical products, such as APIs and agrochemicals.

Kainic Acid-Based Agonists of Glutamate Receptors: SAR Analysis and Guidelines for Analog Design

A comprehensive survey of kainic acid analogs that have been tested for their biological activity is presented. Specifically, this review (1) gathers and compares over 100 kainoids according to a relative activity scale, (2) exposes structural features required to optimize affinity for kainate receptors, and (3) suggests design rules to create next-generation KA analogs. Literature SAR data are analyzed systematically and combined with the most recent crystallographic studies. In view of the renewed interest in neuroactive molecules, this review aims to help guide the efforts of organic synthesis laboratories, as well as to inform newcomers to KA/GluK research.

Gene polymorphism IL17A (RS8193036; RS2275913) in the Brucellosis

Purpose: The study of association of polymorphisms IL17A gene (rs8193036; rs2275913) with brucellosis. Methods & Materials: Study Design: Case-control. Group of cases - 89 patients with brucellosis, and the control group was 414 people who did not suffer from brucellosis. Genotyping of IL17A (rs8193036; rs2275913) was carried out by the Real-time PCR method in the Organic synthesis laboratory of the “National Center of Biotechnologies”, Astana, Kazakhstan. Statistical calculations were carried out on a calculator for genetic calculations under the Gene Expert program. (http://gen-exp.ru/calculator_or.php). Results: It has been established that the factors predisposing to brucellosis can be the C allele and the CC genotype (OR (95% CI) = 4.42 (3.00-6.51) and 7.32 (4.39-12.20), respectively), and T allele, CT and TT genotypes of polymorphism rs8193036 of the gene IL17A (OR 95% CI) = 0.23 (0.15-0.33), OR (95% CI) = 0.43 (0.26-0, 72) and 0.19 (0.09-0.43), respectively) - the factors of resistance. Studies on the association of polymorphism rs2275913 of the IL17A gene revealed that the factors of predisposition to brucellosis are G and GG (OR (95% CI) = 2.26 (1.51-3.38) and 2.25 (1.40-3.61)), respectively, while the resistance factors may be the allele A (OR (95% CI) = 0.44 (0.30-0.66)) and the AA genotype (OR 95% CI) = 0.08 (0.01-0.61)). Conclusion: The results of our study indicate that in brucellosis there is a possible association of brucellosis with polymorphisms of the IL17A gene (rs8193036, rs2275913).

Synthesis of reference compounds related to Chemical Weapons Convention for verification and drug development purposes – a Brazilian endeavour

This paper deals with challenges that Brazilian Army Organic Synthesis Laboratory has been going through to access reference compounds related to the Chemical Weapons Convention in order to support verification analysis and for research of novel antidotes. Some synthetic procedures to produce the chemicals, as well as Quality Assurance issues and a brief introduction of international agreements banning chemical weapons are also presented.

Mechanochemical Organic Synthesis: The Art of Making Chemistry Green

Despite growing interest in mechanochemistry, its application in the organic-synthesis laboratory has still not reached the level of being commonplace. Inspired by this apparent underrepresentation of mechanochemical practice in the broad organic-chemistry community, this article aims to highlight some of the most interesting aspects of modern mechanosynthesis, with particular emphasis on the potential of mechanochemistry to allow reaction discovery and the development of novel synthetic approaches.

Flow Electrolysis Cells for the Synthetic Organic Chemistry Laboratory.

Electrosynthesis has much to offer to the synthetic organic chemist. But in order to be widely accepted as a routine procedure in an organic synthesis laboratory, electrosynthesis needs to be presented in a much more user-friendly way. The literature is largely based on electrolysis in a glass beaker or H-cells that often give poor performance for synthesis with a very slow rate of conversion and, often, low selectivity and reproducibility. Flow cells can lead to much improved performance. Electrolysis is participating in the trend toward continuous flow synthesis, and this has led to a number of innovations in flow cell design that make possible selective syntheses with high conversion of reactant to product with a single passage of the reactant solution through the cell. In addition, the needs of the synthetic organic chemist can often be met by flow cells operating with recycle of the reactant solution. These cells give a high rate of product formation while the reactant concentration is high, but they perform best at low conversion. Both approaches are considered in this review and the important features of each cell design are discussed. Throughout, the application of the cell designs is illustrated with syntheses that have been reported.

An extended channel length microflow electrolysis cell for convenient laboratory synthesis

A spiral, extended channel length microflow cell designed for routine and convenient application in an organic synthesis laboratory is described. The performance of the cell is demonstrated using two syntheses and it is shown that high selectivities and high conversions in a single pass can be achieved as well as the formation of products at a rate of up to 25mmol/h (~3g/h). The cell is also well suited to carrying out the optimisation of reaction conditions with electrolyses completed on a timescale of minutes.

Sitting above the maze: recent model discoveries in molecular science

The 2013 Nobel Prize in Chemistry has convinced the world that how important the role that computational sciences play in chemical and materials sciences. In this review, computational methods and rational molecule design, including quantum mechanics and molecular mechanics methods, have been applied to study electronic structures and the interactions in a number of important applications at molecular level. The applications which include bioactive compounds, drug candidates and photoactive molecules at Swinburne University in the past several years are discussed. The research is in close collaboration with world class experimental groups from spectroscopy, organic and medicinal synthesis laboratories and most recently to γ-ray spectroscopy as well as other theory groups in the world. Ionisation spectra of biomolecules and bioactive compounds including amino acids, DNA bases, cyclic dipeptides, drug candidates, complexes and photoactive molecules are discussed. Most recent projects such as infrared spectral studies of ferrocene, rational design of organic dyes in solar cell applications, and recent development in γ-ray spectra of positron annihilation in molecules are highlighted.

ChemInform Abstract: Planetary Ball Mills as Innovative Reactors in Organic Synthesis Laboratory.

ChemInform Abstract: Planetary Ball Mills as Innovative Reactors in Organic Synthesis Laboratory.

Purification of Olefin Metathesis Reaction Products via Straightforward and Low-Cost Protocols

From the point of view of an organic chemist, the discovery of novel and efficient carbon-carbon bond forming reactions is a continuous scientific quest. Olefin metathesis, a metal-catalyzed reaction, can be considered as one of the most robust tools in this respect. As a result, metathesis has been widely used over various chemistry and materials science fields. The increased popularity of this powerful transformation is mostly due to the development of highly efficient, functional group tolerant, and air- and moisture-stable ruthenium catalysts. However, the complete removal of ruthenium from the reaction products, in order to avoid undesired side-reactions, isomerization, or even the decomposition of products, is very often a highly challenging task. The present article focuses on the most straightforward and efficient methodologies for the removal of ruthenium residues from olefin metathesis post reaction mixtures. These purification protocols can be easily carried out in any common organic synthesis laboratory, needless of specialized reagents and experimental setup.

Natural Product Total Synthesis in the Organic Laboratory: Total Synthesis of Caffeic Acid Phenethyl Ester (CAPE), A Potent 5-Lipoxygenase Inhibitor from Honeybee Hives

Natural products play a critical role in modern organic synthesis and learning synthetic techniques is an important component of the organic laboratory experience. In addition to traditional one-step organic synthesis laboratories, a multistep natural product synthesis is an interesting experiment to challenge students. The proposed three-step synthesis describes the total synthesis of the caffeic acid phenethyl ester (CAPE), a potent 5-lipoxygenase inhibitor from honeybee hives. Recrystallization, flash column chromatography, and circular chromatography were used for purifications. Structure verification for CAPE and all intermediates uses infrared (IR) and nuclear magnetic resonance (NMR, 1H and 13C) spectroscopy and mass spectrometry (MS). This experiment is appropriate for a second-year organic chemistry laboratory.