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

Autor/inn/en	Hopson, Russell; Lee, Po Yin Bowie; Hess, Kathless M.
Titel	1-Dimensional Selective Nuclear Overhauser Effect NMR Spectroscopy to Characterize Products from a Two-Step Green Chemistry Synthesis
Quelle	In: Journal of Chemical Education, 95 (2018) 4, S.641-647 (7 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Zusatzinformation	ORCID (Hess, Kathless M.)
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
DOI	10.1021/acs.jchemed.7b00494
Schlagwörter	Organic Chemistry; Spectroscopy; Undergraduate Students; Science Laboratories; Laboratory Experiments; Science Experiments; Discovery Learning; Synthesis; Rhode Island + Suchen Sie Ihr Suchwort? Organische Chemie; Spektroskopie; Laboratory work; Laborarbeit; Entdeckendes Lernen
Abstract	One dimensional (1-D)[superscript 1] H and [superscript 13]C NMR experiments are common tools used in undergraduate organic laboratories to characterize synthesized molecules. However, 1-D NMR spectra cannot always provide unambiguous structure determination. In research laboratories, advanced NMR spectroscopy methods are employed for structural assignments of synthesized molecules. This experiment is designed to introduce undergraduate students to the application of an advanced method of [superscript 1]H NMR spectroscopy, the 1-D selective nuclear Overhauser effect (NOE) experiment, to fully characterize the structure of two compounds. The experiment features a two-step green chemistry synthesis to produce the two compounds. In the first step of the synthesis, 4-methylaniline ("para"-toluidine) is acetylated to form 4'-methylacetanilide ("para"-acetotoluidide). The 1-D selective NOE method is used to identify the two different methyl groups present in 4'-methylacetanilide and to assign the aromatic protons. For the second step of the synthesis, bromination of the aromatic ring of 4'-methylacetanilide is accomplished using Oxone and ammonium bromide in an aqueous solvent. The 1-D selective NOE method is applied to determine the regioselective product of the bromination reaction. The 1-D selective NOE experiment is readily accessible and easily implemented. Successful interpretation of the 1-D selective NOE results leaves students confident in making structural assignments that would otherwise be based solely on theory or software prediction. (As Provided).
Anmerkungen	Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01