Preparation and Properties of a Stable Organic Cation: A Microscale Experiment for Organic Chemistry

• Published in: Journal of chemical education Vol. 73; no. 6; p. A124
• Main Authors: Manfredi, K. P, McGrew, L. A
• Format: Journal Article
• Language: English
• Published: Easton Division of Chemical Education 01-06-1996; American Chemical Society
• Subjects: Carbon; Carbon 13; Chloride; Climate; Hydrochloric acid; Inhalants; NMR; Nuclear magnetic resonance; Organic chemistry; Research Methodology; Steam; Vacuum distillation; Water; New York; United States > US; The Microscale Laboratory; Second-Year Undergraduate; Hands-On Learning / Manipulatives; Synthesis; Organic Chemistry
• ISSN: 0021-9584; 1938-1328
• DOI: 10.1021/ed073pA124

This article describes the microscale synthesis and characterization of the flavylium cation. It is a suitable experiment for students in the second semester of organic chemistry laboratory. Crossed-Aldol condensation of salicylaldehyde with acetophenone, follwed by acid-catalyzed cyclization, is used to prepare the cation. It is characterized using 13C NMR spectroscopy. Students are assisted in assigning the resonances by the Mulliken charge distribution, obtained by semi-empirical MO calculations using SPARTAN (Wavefunction, Inc.). The cation is isolated as the stable ferrichloride salt.