Paal--Knorr reactions are a classical method for synthesizing pyrroles, using 1,4-dicarbonyl compound and amine as reactants. It has the characteristics of green chemistry, as only two molecules of water are lost. In this teaching and learning experiment, 2,5-hexanedione and 4-"tert"-butylaniline were used to synthesize…

The helium-plasma (HePI) ionization mass spectrometry method was used to track the formation of reaction products and consumption of reactants by continually monitoring the vapors in the reaction headspace in real time. Two examples of the application procedure are presented here: a nucleophilic acyl substitution reaction and a 1,4-nucleophilic…

A renewed experimental procedure for the unknown carbonyl experiment has been developed using hydrazone synthesis, thin layer chromatography (TLC) analysis, and melting point determination to differentiate between structurally similar ketones and aldehydes in undergraduate organic chemistry practical courses. Benzaldehyde, p-tolualdehyde,…

In this two-session experiment for an organic chemistry lab, students prepare a macrocyclic host compound--namely, a pillar[5]arene--by means of a templated 1,4-dimethoxybenzene/formaldehyde cyclo-oligomerization (session 1), and then, they explore its molecular recognition properties toward the 1,8-diaminooctane guest with the aid of [superscript…

Discussion-based outcomes of organic chemistry laboratory experiments form a powerful tool to create a learning environment, facilitate teamwork, and build scientific skills and analytical ability for undergraduate science students. A Knoevenagel-type condensation reaction was selected to demonstrate these results by taking phenylacetonitrile and…

In primary organic chemistry, students learn about the dehydration of ethanol to ethylene with concentrated sulfuric acid. Similar reactions(the dehydration of alcohols) exist in nature. For example, various alkenes with aromas are synthesized from linalool, a monoterpene tertiary alcohol. In this laboratory experiment, we report experiments…

In this second-semester organic chemistry lab experiment, students work collaboratively using a combination of chemical synthesis and NMR spectroscopy to investigate the diastereoselectivity associated with the Meerwein-Ponndorf-Verley (MPV) reduction of two ketone substrates having carbonyl groups flanked by an [alpha]-chiral carbon with…

Tofu, a traditional Chinese food, is now popular worldwide. However, few people notice the chemistry that is involved in its production. To shed light on this, we have designed a simple demonstration for lower-level undergraduates in organic chemistry or biochemistry courses to help them understand the chemistry principles that underlie the…

Laboratory experiments provide training to students in experimental techniques and strengthen the understanding of the theory. Herein, a new introductory experiment for organic chemistry laboratory courses is described where students are trained in washing an unknown neutral organic compound using liquid/liquid extraction, isolating it via…

Applying the idea of green chemistry, we extended an esterification teaching experiment with isoamyl alcohol and acetic acid and reused isoamyl acetate in the transesterification reaction with KOH as the catalyst. As a result, isoamyl alcohol was produced and could be reused for the teaching experiment. The simplified experimental method achieved…

A comprehensive teaching experiment plan tailored forthird-yearundergraduates has been developed. Initially, instructors synthesize(E)-2-(4-((4-(2-hydroxyethoxy)-3-methylphenyl)­diazenyl)­phenoxy)-ethan-1-ol­(M-Azo-2)monomer as part of the preclass preparation. Subsequently, studentsperform an acylation reaction experiment to prepare an…

A discovery-based experiment for the synthesis of arylpropiolic acids via carboxylation of arylacetylenic Grignard reagents was developed. This experiment shows the "dual utility" of Grignard reagents. In the synthesis of arylpropiolic acids reported here, we have demonstrated the use of a Grignard reagent as a base in a "Grignard…

An undergraduate laboratory experiment has been developed for the synthesis of a reactive cross-linker that is useful in various highly visual demonstrations of organic reactivity, click chemistry, and biobased polymer synthesis. A triazolinedione-based cross-linker, which is known as a useful reagent for click chemistry, can be obtained from…

A multioutcome, discovery-based column (CC) and thin layer chromatography (TLC) experiment has been designed for introductory organic chemistry. Multiple outcomes were established using commercially available two- and three-component analgesic medications based on acetaminophen, acetylsalicylic acid (aspirin), and ibuprofen. A series of 11…

Hydrogels are soft water-rich materials with physical properties that can be easily tuned by modifying their network structure. For instance, increasing or decreasing the cross-linking density has a profound effect on their water absorption capabilities and mechanical strength. These physical changes are showcased in a new experiment for organic…