Cart
Article
Nucleophilic Addition vs. Substitution: A Puzzle for the Organic Laboratory
Hi-Res PDFPurchase the full-text
- PDF/HTML,
figures/images,
references and tables,
(where available)
Abstract
An experiment has been devised that allows a student to prove that nucleophilic addition to a keto group predominates over nucleophilic substitution at an ester group in a case in which both are theoretically possible. The student reacts ethyl 2-acetyl-3-oxobutanoate with hydrazine and with phenylhydrazine and shows, by 1H NMR spectroscopy, that the products are 4-carbethoxypyrazoles and not 4-acetylpyrazolones. Students may also use 1H NMR to show that ethyl 2-acetyl-3-oxobutanoate is 100% enolized in carbon tetrachloride solution.
The experiment asks the student to solve a puzzle, which adds to the student's interest and sense of excitement. It can also be used to teach students how to conduct a literature search. The products obtained are described in the literature, so students can be asked to compare their melting points with those of other workers.
Keywords (Audience):
Second-Year UndergraduateKeywords (Domain):
Organic ChemistryKeywords (Pedagogy):
Hands-On Learning / ManipulativesKeywords (Subject):
Learning TheoriesCiting Articles
Citation data is made available by participants in CrossRef's Cited-by Linking service. For a more comprehensive list of citations to this article, users are encouraged to perform a search in SciFinder.
This article has been cited by 4 ACS Journal articles (4 most recent appear below).
A Nitration Reaction Puzzle for the Organic Chemistry Laboratory
Milton J. Wieder and Russell BarrowsJournal of Chemical Education2008 85 (4), 549A Nitration Reaction Puzzle for the Organic Chemistry Laboratory
Milton J. Wieder and Russell BarrowsJournal of Chemical Education2008 85 (4), 549Treatment of phenylacetic acid with 90% HNO3 yields a product, I, whose observed melting point is 175–179 °C and whose equivalent weight is approximately 226 grams. Treatment of phenylacetic acid with 70% HNO3 yields a product, II, whose observed melting ...
The State of Organic Teaching Laboratories
Gail HorowitzJournal of Chemical Education2007 84 (2), 346The State of Organic Teaching Laboratories
Gail HorowitzJournal of Chemical Education2007 84 (2), 346This review explores the dramatic changes that have taken place in the organic chemistry laboratory course over the last two to three decades. The most significant changes have been in the areas of pedagogy and technology. Significant inroads have been ...
Use of Optical Rotation and NMR Signal Counting To Identify Common Aldoses
John AlmyJournal of Chemical Education2004 81 (5), 708Use of Optical Rotation and NMR Signal Counting To Identify Common Aldoses
John AlmyJournal of Chemical Education2004 81 (5), 708An inexpensive, small scale experiment for second semester organic students describes the unambiguous identification of a common aldose "unknown" from five possible candidates: glucose, mannose, galactose, arabinose, or xylose. The aldose is first reduced ...
A Discovery Approach to Three Organic Laboratory Techniques: Extraction, Recrystallization, and Distillation
Gail HorowitzJournal of Chemical Education2003 80 (9), 1039A Discovery Approach to Three Organic Laboratory Techniques: Extraction, Recrystallization, and Distillation
Gail HorowitzJournal of Chemical Education2003 80 (9), 1039This article describes three discovery-based experiments geared toward the beginning organic chemistry laboratory student. Each experiment focuses on one of the following purification techniques: extraction, recrystallization, or distillation. Unlike ...
Tools
-
Add to Favorites
-
Download Citation
-
Email a Colleague -
Permalink
Order Reprints
Rights & Permissions
Citation Alerts
History
- Received: August 03, 2009
ACS
Network
Facebook
Tweet This
CiteULike
Newsvine
Digg This
Delicious
