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ERIC Number: EJ920485
Record Type: Journal
Publication Date: 2010-Nov
Pages: 2
Abstractor: As Provided
Reference Count: 8
ISSN: ISSN-0021-9584
Fast Hetero-Diels-Alder Reactions Using 4-Phenyl-1,2,4-Triazoline-3,5-Dione (PTAD) as the Dienophile
Celius, Tevye C.
Journal of Chemical Education, v87 n11 p1236-1237 Nov 2010
A hetero-Diels-Alder reaction that proceeds rapidly and only requires a simple filtration to purify the product is presented. The dienophile, 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD), is prepared by the heterogeneous oxidation of 4-phenylurazole by the bromenium ion, Br[superscript +], generated in situ by the oxidation of potassium bromide by Oxone. PTAD is reacted with both cyclopentadiene and 1,3,5-cycloheptatriene, and the resulting products are analyzed by NMR spectroscopy. PTAD reacts with cyclopentadiene in the expected fashion; however, it reacts exclusively with the norcaradiene valence tautomer of 1,3,5-cycloheptatriene to form a single cycloadduct. The speed of these reactions allows for more of a three-hour laboratory period to be devoted to spectral characterization and data analysis than in similar experiments. This laboratory experiment is suitable for second- or third-year organic chemistry courses. (Contains 2 schemes.)
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:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A