Hello, suziescrew.
Searching for this answer seems to require just the right combination
of chemical terms and plain English. Specifically, it means knowing
that HNO3 is nitric acid and EtOH is ethanol.
The clearest procedure is this experiment posting from the Department
of Chemistry at Pennsylvania State University, available at:
http://courses.chem.psu.edu/chem36/Experiments/Exp121.pdf
The textbook source is Macroscale and Microscale Organic Experiments,
2nd. Edition, by K. L. Williamson. Houghton Mifflin, Boston, 1994,
page 494.
"Procedure: Nitric Acid Oxidation of Benzoin
?
"Heat a mixture of 100 mg of benzoin and 0.35 mL of concentrated
nitric acid in a small beaker placed in boiling water for about 11
min. Carry out the reaction in the hood to avoid breathing evolved
nitrogen oxides. Be sure all the benzoin gets washed down inside the
tube and is oxidized. When reaction is complete, add 2 mL of water to
the reaction mixture, cool
to room temperature, and stir the mixture for a minute or two to
coagulate the precipitated product.
"Remove the solvent with a Pasteur pipette, and wash the solid with 2
mL more water. Dissolve the solid in 0.5 mL of hot ethanol, and add
water dropwise to the hot solution until the solution appears to be
cloudy, indicating it is saturated. Heat to bring the product
completely into solution, and allow it to cool slowly to room
temperature. Cool the tube in
ice, and isolate the product using the Hirsch funnel. Scrape the
benzil onto a piece of filter paper, squeeze out excess solvent, and
allow the solid to dry."
If you're interested, the Home Page for Penn State's "Introductory
Organic Laboratory" course is available at:
http://courses.chem.psu.edu/chem36/
linking to this and other experiments.
Search Strategy:
benzoin benzil HNO3
Good luck!
brotine-ga |
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