CHEM 221 Synthesis of Phenacetin via Williamson Ether Synthesis PPT

hello please help with organic chem ll lab report help please due by mondaythank you!!!!!video for experimentFor this experiments use the amounts of reactants given in the procedure to calculate your theoretical yield.

Use 0.240 g as your actual yield.

THE LABORATORY NOTEBOOK
Use a bound notebook with duplicate pages to minimize the possibility for losing pages.
This can be purchased in the bookstore. The first two pages should be reserved for a Table of
Contents. Write your notes in such a way that a reader will know exactly what you did and
could repeat your work. Record your observations in ink directly into the notebook as you do
the experiment. Transcribing data later from a scratch copy could result in miscopied or lost
data.
Each experiment that will be done will be posted to Moodle and a copy should not be
brought to the lab session. You need to read the experiment before coming to lab, and have a
procedure outlined in your notebook. The key word here is “outlined”. Do not copy the
procedure word for word into your notebook! As you proceed through the experiment, you
should record thorough observations and detailed procedures of what you are actually doing.
Most of the labs will require the full time, and there simply is not an extra 30-60 minutes for you
to be reading the material for the first time.
Full Lab Report. In addition to a title, the report should contain the following sections:
I. Introduction. A short (1 or 2 sentence) summary of the concept (purpose) behind the
experiment.
II. Main reactions (side reactions). Only required when chemical reactions take place (not
physical changes). This section is not necessary for many of the early experiments where no
reaction occurs.
III. Table of reactants and products. Set up a Table of Reactants and Products as an aid in
summarizing the amounts and properties of reagents and catalysts being used and product(s)
being formed. Only those reactants, catalysts, and products that appear in the main reaction
should be listed in the table; many other reagents may be used in the work-up and purification of
the reaction mixture, but these should not be entered in the table. Include the name, molecular
weight, weight used, boiling points, melting points, density, and solubility. For those
experiments that do not involve a reaction, you should give the structure and relevant properties
of compounds used.
IV. Procedure. You will be required to write a procedure in your notebook before coming to
class. Be sure that the procedure contains enough detail so that you can perform the experiment .
Note any deviations from the lab handout procedure.
V. Observations. While performing the experiment, keep notes on what was observed. One
way to do this efficiently is to divide the page into two columns – one for procedure and one for
observations.
VI. Calculations. All math must be shown with actual amount measured in lab. Examples are
theoretical yield, percent recovery, percent yield, percent composition, Rf, etc.
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VII. Results and conclusions. Calculated yields, measured physical properties, and graphical
results should be shown here. Spectroscopic data should also be included. Make a brief
summary of results from the experiment, such as identity of the product or unknown. Give
evidence that supports your conclusions, for example melting point, yield, or IR data.
The written notebook, as well as lab techniques and product quality will contribute to
your lab grade. Remember to turn in the original white copy from your notebook at the
beginning of the lab session after the experiment. There will be a penalty for lateness (see the
laboratory syllabus).
General format of the sections in the lab report and how they should appear in your lab
notebook. If you follow this guide, you are likely to improve your lab grade.
Introduction: (5 pts.)
The purpose of this lab is … Keep brief and use complete sentences
Reaction with mechanism: (10 pts.)
Mechanism must be with the chemicals YOU are using in lab. R- will not be accepted.
Table (must be in table format and do not include solvents) (15 pts.)
Molecular
Amount
mol or nmol Density if
weight
actually
used for
applicable
(g/mol)
used in g,
main
mg, or mL
reactants
(must
specify)
Name and
structure
of
compound
used
Same as
above for
as many
as
applicable
Last space
mol
used for
expected
product
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Melting
point (ºC) if
applicable
Boiling
point (ºC)
if
applicable
Procedure and observation are next to each other (not procedure and then observation below it).
Observations should correlate with the procedure step. Leave room for any procedural changes
the instructor may give, you can use the observation space if need be.
Procedure: (10 pts.)
Numbered step by step instructions
Observations: (10 pts.)
Some examples
1. heat to 156ºC
2. dissolve in sol’n
3.
4. weigh 350 mg of reagent
in briefing – change temp 165ºC
most dissolved, but not all the sol’n turned
green
actual weight 0.348g (white powder)
Does not have to be complete sentences
One should be able replicate experiment by
what is written here
Does not have to be complete sentences
Actual amounts used
Colors, textures, odors, temperatures
Calculations: (15 pts)
Theoretical yield:
Must show all math with all reactants and the amount that YOU actually measured.
Identify limiting reagent and which is the theoretical yield of the product
Show ALL calculations
Results and Conclusion: (35 pts.)
This is written AFTER the lab
Data written in tabular form
Summarize data in paragraph form – refer reader to spectra if necessary
ON SPECTRA, DRAW THE STRUCTURE AND IDENTIFY PEAKS AS SHOWN ON
EXAMPLE and summarize in table
Attach all spectra and graphs
Filename: chem221(2)laboratorynotebook18
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THE WILLIAMSON ETHER SYNTHESIS
The Williamson ether synthesis is an organic reaction, forming an ether from an alkyl halide and
an alcohol. This reaction was developed by Alexander Williamson in 1850. It involves the
reaction of an alkoxide ion with a primary alkyl halide via an SN2 reaction.
The Williamson reaction is widely used in both laboratory and industrial synthesis, and remains
the simplest and most popular method of preparing ethers. Both symmetrical and asymmetrical
ethers are easily prepared.
Phenacetin (an analgesic) may be synthesized as an example of the Williamson ether synthesis
It was first synthesized in 1878 by Harmon Morse.
acetaminophen
1-iodoethane
phenacetin
PROCEDURE
1. Weigh an Extra-Strength Tylenol tablet. Pulverize the tablet with mortar and pestle. Weigh
out 0.22 g and place it in a dry 15-ml round-bottom flask along with 0.28 g of finely
pulverized K2CO3 (mortar and pestle) and 3.0 mL of butanone. Carefully add 0.28 mL of
ethyl iodide (1-iodoethane) with a syringe.
2. Add a stir bar; attach a microscale water-cooled condenser to the flask. Heat the mixture
under reflux directly on a hot plate at medium setting for 1 hour. In the meantime, obtain the
IR of acetaminophen.
3. Turn off the heat. Allow the mixture to cool down. Add 4 mL of water to the flask and
transfer its contents to a 16 x 125 mm test tube with a screw cap. Rinse round-bottom flask 4
times with 1 mL of tert-butyl methyl ether (BME) and add the rinsings to the test tube.
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4. Cap the test tube and shake the layers. Vent to release the pressure by unscrew the cap
momentarily. With a Pasteur pipet remove the lower (aqueous) layer. Transfer the aqueous
layer to another 16 x 125 mm, screw-cap test tube. Keep the organic layer in the original test
tube.
5. Extract the aqueous layer with 2.5 ml, of BME. Remove the aqueous layer with a Pasteur
pipet (save it until the end in a labeled test tube, and then discard it). Transfer the organic
layer to the screw-cap test tube with the original organic layer.
6. Add 2.5 ml, of 5% aqueous NaOH to the combined organic layers and shake well. Let the
layers settle and remove the lower aqueous layer with a Pasteur pipet. Repeat the extraction
with another 2.5-ml portion of 5% NaOH. Save the aqueous layers until the end of the
experiment.
7. Extract the organic layer with 2.5 ml, of saturated sodium chloride solution. If emulsions
form during these extractions, they can be broken by centrifugation (1000-2000 rpm for a few
minutes). Dry the organic layer by adding magnesium sulfate little by little with a
microspatula until the solid runs freely in the liquid. Let the system stand for 5 minutes with
occasional swirling.
8. Filter the mixture using a Pasteur pipet with a cotton plug and receive the filtrate in a dry,
pre-tared, 25-ml round-bottom flask. Evaporate off the solvent using a rota-vap. Weigh the
flask with the product. Calculate the crude % yield. Scrape out the crude phenacetin and
determine its melting point. yield. Scrape out the crude phenacetin and determine its melting
point.
9. Review recrystallization from mixed solvents and microscale recrystallization. Using a Craig
tube, recrystallize the product by dissolving it in the minimum amount of hot ethyl acetate.
Heat the system in a sand bath, and continuously stir it by rolling a microspatula between
your fingers. To the hot solution add hot hexane dropwise until the solution becomes cloudy.
Cool the solution to induce crystallization and collect the crystals by centrifugation.
Determine the weight and melting point.
10. Compare the IR of the product with the spectrum of acetaminophen. Interpret the 1H-NMR
of the product.
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Acetaminophen
3
Phenacetin
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H NMR of Phenacetin
Retrieved from https://www.chemicalbook.com/SpectrumEN_62-44-2_1HNMR.htm
Adapted from http://www.users.miamioh.edu/gungbw/CHM254_html/pdfs/williamsonethersyn.pdf
filename: Williamson Ether Synthesis Lab 21821
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