Undergraduate Organic Laboratory Research Articles

Levulinic Acid Promoted Cyclization Cascade. A Holistic Research-Based Approach to an Undergraduate Organic Spectroscopy Laboratory

Levulinic Acid Promoted Cyclization Cascade. A Holistic Research-Based Approach to an Undergraduate Organic Spectroscopy Laboratory

Two-Step Synthesis of 4-Hydroxy-3,5-dimethylphenyl Benzoate: Undergraduate Organic Laboratory of Electrophilic Aromatic Substitution and Nucleophilic Aromatic Substitution

Two-Step Synthesis of 4-Hydroxy-3,5-dimethylphenyl Benzoate: Undergraduate Organic Laboratory of Electrophilic Aromatic Substitution and Nucleophilic Aromatic Substitution

Applying Reuse and Reduce in an Undergraduate Organic Laboratory: Sustainable Practices

In this section of Resonance, we invite readers to pose questions likely to be raised in a classroom situation. We may suggest strategies for dealing with them, or invite responses, or both. “Classroom” is equally a forum for raising broader issues and sharing personal experiences and viewpoints on matters related to teaching and learning science.Amidst the Covid-19 pandemic, we have planned a strategy for our institution which aims towards reuse and reduce principles of Green Chemistry. Organic preparations in the undergraduate curriculum can be utilized for other sister laboratory experiments such as recrystallization, determination of physical constants (m.pt) and detection of extra elements, detection of functional group and in qualitative analysis. The product of preparation can also be subjected to a second synthesis. This approach will reduce the amount of chemicals needed for carrying out experiments other than organic preparations. This paper illustrates a few organic preparations which can be reused for other companion laboratory exercises. This approach may set a model towards sustainability for other undergraduate laboratories.

An Updated Simple SN2 Reaction for the Undergraduate Organic Laboratory

An Updated Simple S_N2 Reaction for the Undergraduate Organic Laboratory

Facile Amide Bond Formation with TCFH-NMI in an Organic Laboratory Course.

A new undergraduate organic laboratory experiment has been developed for amide bond formation between biorenewable 2-furoic acid and either of two substituted piperazines to prepare medicinally relevant amide products using a procedure with industrial significance. The reactions proceeded smoothly under ambient conditions using the combination of N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate (TCFH) and N-methylimidazole (NMI) in a minimal volume of acetonitrile with a direct crystallization upon addition of water. Students successfully collected their product by filtration and then characterized it by NMR (1H, 13C, COSY, DEPT-135, HSQC), IR, MS, and melting point. Students also explored the reaction mechanism and compared green chemistry aspects of their procedure with literature routes. A virtual version of the experiment was adapted for remote instruction.

Green Oxidative Synthesis of 2-Nitrobenzaldehyde: An Oxidative Synthesis Experiment for the Undergraduate Organic Laboratory

Green Oxidative Synthesis of 2-Nitrobenzaldehyde: An Oxidative Synthesis Experiment for the Undergraduate Organic Laboratory

Microwave‐assisted Groebke‐Blackburn‐Bienaymé multicomponent reaction to synthesize imidazo fused heterocycles via in‐situ generated isocyanides from N‐formylamines: An undergraduate organic laboratory experiment

AbstractA one‐pot methodology is developed for the direct conversion of N‐formylamine, 2‐amino pyridine, and aldehyde into 2,3‐substituted imidazo[1,2‐a]pyridine heterocycles using I2‐PPh3‐Et3N reagent system under microwave irradiation. During the reaction, I2‐PPh3‐Et3N converts N‐formylamine into isocyanide, which in the presence of in‐situ generated hydrogen iodide (HI) undergoes Groebke‐Balckburn‐Bienaymé (GBB) multicomponent reaction with aldehyde and 2‐aminopyridine. The in‐situ generated HI eliminates the need for an external catalyst for the GBB reaction. The developed process incorporates the use of readily accessible and cheap reagents and also avoid a separate step for the synthesis of isocyanides having disagreeable odor. Fourteen different GBB based heterocycles have been synthesized to demonstrate the feasibility of the optimized protocol. The preparation of N‐formylamines utilized in the synthesis is also elaborated and the overall process was optimized to be suitable for a typical undergraduate organic laboratory experiment. One of the final products was characterized using FT‐IR, 1H NMR, 13C NMR, DEPT, COSY, HSQC, HRMS, and single‐crystal X‐ray diffraction. Overall, the experiment will be useful in the organic chemistry curriculum to teach about multicomponent reactions, the importance of isocyanides in organic synthesis, formylation of amines, application of microwave irradiation in organic synthesis, and structural elucidation of small organic molecules.

Gas Chromatography–Mass Spectrometric Analysis of Derivatives of Dibenzalacetone Aldol Products

The aldol condensation reaction is one of the many synthesis reactions carried out in second semester organic chemistry laboratories. This reaction was integrated into a novel experiment requiring students to synthesize dibenzalacetone derivatives using the crossed-aldol condensation by reacting different types of benzaldehyde derivatives with acetone, followed by analyzing those products using spectrometric and spectroscopic methods, especially gas chromatography–mass spectrometry (GC–MS). The main objective of this 2 week lab experiment compared to other procedures in the literature was the analysis of the final aldol product using GC–MS methods rather than solely nuclear magnetic resonance (NMR) spectroscopic methods. During the first week’s 3 h laboratory period, students completed the reaction with a known benzaldehyde derivative and acetone to synthesize their aldol product. In the second week, students calculated the percent yield of their product, determined the product’s melting point range, and analyzed the product by thin-layer chromatography, NMR, and GC–MS methods. Students also strengthened their skills of spectral interpretation using NMR spectroscopy, especially distortionless enhancement by polarization transfer NMR, an NMR technique rarely covered in undergraduate organic laboratory sections. Students spent more classroom time during week two, analyzing GC–MS data. Students were shown how to use molecular model kits to understand the fragmentation of compounds in the mass spectrum. As a result, the students who performed this experiment increased their general knowledge of GC–MS spectrometric techniques, including identification of compounds based on their fragmentation pattern.

Process Development of the Weiss–Cook Reaction for the Preparation of cis-1,5-Dimethylbicyclo[3.3.0]octane-3,7-dione in the Undergraduate Organic Laboratory

A four week laboratory experiment was designed on the basis of a modification of the Weiss–Cook reaction for the preparation of cis-1,5-dimethylbicyclo[3.3.0]octane-3,7-dione. In general, this very...

Approaches to Incorporating Green Chemistry and Safety into Laboratory Culture

A systems thinking approach to incorporating green chemistry and safety into laboratory culture is vital, as chemists will be at the molecular level of the innovative solutions to our global challenges. Training chemists to have the skills and culture to accomplish this feat in the safest way possible is pivotal to safe working conditions within the chemical industry and extends to society in a sustainable future for the planet. Today, we know green chemistry to be the framework for conducting chemistry in a manner that is conducive to life. In this article, we emphasize how framing green chemistry through the lens of systems thinking can build a culture of safety in the laboratory. This can shift the focus of safety culture from compliant to proactive, as assessing the risk of performing a reaction gives chemists ownership and control of their safety. The Guide to Green Chemistry Experiment for Undergraduate Organic Laboratories is highlighted as one approach. The guide utilizes the green chemistry metric, DOZN 2.0, which allows for a quantitative method toward recognizing and assessing the risks of hazards in a chemical reaction. Within the research enterprise, green chemistry is a cornerstone of the Green Laboratories movement and helps institutions to meet both safety and sustainability strategies. Yet, in order for these efforts to be successfully implemented, environmental health and safety (EH&S) and sustainability professionals must engage one another and communicate effectively. Understanding how motivational focus affects our perceptions and attitudes can allow stakeholders to better partner on Green Laboratories initiatives and more successfully implement these techniques.

Synthesis, Modification, and Application of Sulfonated Poly(styrene-co-maleic anhydride) as a Stain Blocker for Polyamides: Polymer Chemistry for the Undergraduate Organic Laboratory

A laboratory exercise for the synthesis of a sulfonated styrene-co-maleic anhydride polymer and its application as a stain blocker on nylon-6,10, is described. The effectiveness of the sulfonated polymer to prevent the conjugate base of an acid dye from staining the polyamide is demonstrated. This experiment is designed for second-semester, second-year undergraduate organic chemistry students. Specifically, this laboratory experiment focuses on providing experience with radical chain and step-growth polymerizations, interfacial reactions, electrophilic aromatic substitution (sulfonation), and the importance of intermolecular forces.

A Multioutcome Experiment for the Williamson Ether Synthesis

Williamson ether experiments are commonly performed by students in undergraduate organic chemistry instructional laboratory courses. In this multioutcome experiment, students were provided 4-bromophenol and one of three alkyl halides: 1-bromopentane, 1-bromobutane, or 1-bromo-3-methylbutane. The alkyl halides served as the unknown component of the experiment, and students were given these three as unknown candidates. After isolating the product from the reaction mixture, students analyzed their products using FT-IR and benchtop 1H NMR spectroscopies. The experimental results herein summarize the inclusion of this experiment in the large enrollment second-semester organic chemistry laboratory course over four semesters.

Diastereoselective Synthesis and Characterization of Homoallylic <i>N</i>-<i>tert</i>-Butanesulfinyl Amines: An Asymmetric Synthesis Experiment for the Undergraduate Organic Laboratory

Diastereoselective Synthesis and Characterization of Homoallylic <i>N</i>-<i>tert</i>-Butanesulfinyl Amines: An Asymmetric Synthesis Experiment for the Undergraduate Organic Laboratory

Carbohydrate Characterization through Multidimensional NMR: An Undergraduate Organic Laboratory Experiment

Carbohydrates are an essential group of molecules to the organic chemistry classroom providing molecular relevance to a common ingredient in chemical biology. While the meticulous elucidation of the carbohydrate structures by Fischer and others is an engaging topic in the lecture, there are few laboratory experiments that can emulate carbohydrate complexity. Advanced and multidimensional NMR (2D NMR) techniques such as correlation spectroscopies (COrrelation SpectroscopY (COSY), 13C Distortionless Enhancement by Polarization Transfer (DEPT), and HETeronuclear CORrelation (HETCOR) or Heteronuclear Single Quantum Coherence (HSQC)) have become more routine as they require less time on today’s instruments and are taught more often in lecture. A laboratory experiment is described for second-year introductory undergraduate organic chemistry students that involves the transformation of nutraceutical N-acetyl-d-glucosamine to α-chloroglucosamine tetraacetate. After synthesis and simple workup, students collect four different NMR spectra from which they identify each 1H signal in the product. Students learn to identify each signal’s multiplicity and how multiple NMR experiments are used to characterize a product. Student confidence in NMR characterization was assessed on a small subset through postlab questions and pre- and postsurvey data.

New, Milder Hypervalent Iodine Oxidizing Agent: Using μ-Oxodi(phenyliodanyl) Diacetate, a (Diacetoxyiodo)benzene Derivative, in the Synthesis of Quinones

The synthesis of substituted 1,4-benzoquinones, a biologically important class of compounds, was developed using μ-oxodi(phenyliodanyl) diacetate, a (diacetoxyiodo)benzene-based oxidizing reagent, in order to introduce second-year undergraduate organic laboratory students in their second semester or advanced organic students to increasingly popular and environmentally friendly hypervalent iodine chemistry. This experiment develops on concepts found in the undergraduate organic chemistry curriculum; conveniently fits into approximately two 3 h lab modules; and utilizes regularly found equipment and inexpensive, commercially available chemicals.

Determination of the <i>p</i>/<i>o</i>-Isomer Product Ratios in Electrophilic Aromatic Nitration of Alkylbenzenes Using High Resolution <SUP>1</SUP>H NMR Spectroscopy

High resolution 1H NMR spectroscopy, an increasingly available instrumental method, is used in undergraduate organic laboratory practice as a simpler alternative to gas chromatographic method for the direct determination of the p/o ratios of the crude reaction product from the nitration of alkylbenzenes. The choice of isopropylbenzene as a substrate illustrates that steric effect can be significant in controlling regioselectivity in electrophilic aromatic substitution reactions.

Writing as a Mode of Learning: Staged Approaches to Chromatography and Writing in the Undergraduate Organic Lab

In an effort to provide our second-year organic chemistry students with experience in a scientific investigation, a staged writing approach to a chromatographic experiment was designed. Using best practices from writing in the disciplines approaches to learning, short lab exercises followed by writing assignments with periods of reflection and marker/tutor/instructor feedback were implemented. When combined with a guided peer review process by peer tutors, graded student performance in all sections of a lab report were improved. Four years of development and study found that students increase their written performance involving both the theory and principles of chromatography as well as the craft of writing when guided by a chemistry professional as well as a writing professional.

Overcoming the Hurdle from Undergraduate Lab to Research Lab: A Guided-Inquiry Structural Characterization of a Complex Mixture in the Upper-Division Undergraduate Organic Lab

This guided-inquiry, upper-division undergraduate organic lab experiment, a hybrid of problem-based learning (PBL); process-oriented, guided-inquiry learning (POGIL); and peer-led team learning (PLTL) has been developed to ease the transition from the undergraduate lab to a research lab environment. The characterization of a mixture of camphor and p-coumaric acid involves a complex separation as well as thoughtful NMR experiments and solvent selection. Technique and problem-solving instruction (involving thin-layer and column chromatography as well as 1D [coupling constant analysis] and 2D [COSY, HSQC, and HMBC] NMR spectroscopy) has been simplified for the instructor by the development of videos, detailed notes, and assignment worksheets.

Method for Small-Scale Production of Deuterochloroform.

Deuterochloroform (CDCl3) is a common deuterated solvent for nuclear magnetic resonance (NMR) analyses. The synthesis of significant amounts of CDCl3 for both research use and large undergraduate organic laboratories in a safe and inexpensive manner is appealing. Herein, we describe a convenient laboratory scale preparation of CDCl3 that employs a reduction and decarboxylation of hexachloro-2-propanone (HCP) catalyzed by various pyridines. A PVP catalyst gives cleaner reaction and greater catalyst stability through multiple rounds of recycling, justifying its higher cost compared to pyridine.

1-Dimensional Selective Nuclear Overhauser Effect NMR Spectroscopy To Characterize Products from a Two-Step Green Chemistry Synthesis

One dimensional (1-D) 1H and 13C NMR experiments are common tools used in undergraduate organic laboratories to characterize synthesized molecules. However, 1-D NMR spectra cannot always provide un...