The Chemical EducatorISSN: 1430-4171 (electronic version) Abstract Volume 17
(2012) pp 094-097 Nitration of p-Anisaldehyde: The Effect of Temperature on Product DistributionKwesi Amoa* and Dereck Skeete Medgar Evers College/City University of New York;
Physical Environmental, and Computer Sciences Department, Brooklyn,
New York 11225,
kamoa@mec.cuny.edu Published: 8 June 2012 Abstract. In any organic chemistry class, students are faced with learning functional group transformation where the emphasis is placed on the effect of temperature on various chemical reactions. However, in a laboratory setting students rarely receive any practical hands-on experience in observing this effect. In this laboratory experiment, students nitrate p-anisaldehyde at –15 to –8 °C and from 25 to 40 °C using a nitric acid/sulfuric acid solution. Gas Chromatography/Mass Spectroscopy (GC/MS) analysis of the reaction mixture at a lower temperature range revealed a single compound, 4-methoxy-3-nitrobenzaldehyde (1), while GC/MS analysis of the reaction mixture at the higher temperature range revealed 4-methoxy-3-nitrobenzaldehyde (1) as the major product and three additional by-products – 2-nitroanisole (2), 4-methoxy-3,5-dinitrobenzaldehyde (3), and 2,4-dinitroanisole (4). This laboratory experiment can be used as a template for complementing undergraduate laboratory experiments that exclude the qualitative or quantitative effect of temperature on product distribution.
Key Words: Laboratories and Demonstrations; organic chemistry; aromatic compounds; electrophilic substitution; hands-on learning; inquiry-based laboratory instruction; gas chromatography; mass spectrometry; second-year undergraduate (*) Corresponding author. (E-mail: kamoa@mec.cuny.edu) Article in PDF format (125 KB) HTML format Supporting Materials: Experimental method; identification of by products; list of compounds and CAS registry; gas chromatograms; mass spectra; instructor notes (221 KB).
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