lab 4
preiou5
organic_chem_lab_2.docx
4. When the reaction is complete, “work up” your reaction by first dragging and dropping the separatory
funnel (located in a drawer) on the flask and then adding H2O to the funnel. Extract the organic layer
in the funnel by clicking on the top layer and dragging it to the cork ring on the lab bench. Your target
compound should now be in this flask.
List the starting materials, solvent, reagent, and products formed: Et2O Diethylether, m-chlorophenol acid, 1-methyl-cyclohexene, m-chloropebenzoic acid
How long did it take to finish the reaction? 40 minutes
What are the TLC values (Rf) for (a) Starting Materials: (b) Products:
Write a mechanism for this reaction:
Chapter 2
IR and NMR Spectra
After completing a reaction and working up the products, it is still necessary to confirm that the correct
product was formed. The most common tools used for this analysis are Infrared (IR) and Nuclear
Magnetic Resonance (NMR) spectroscopy. In the virtual laboratory, only 1H NMR spectra are available.
Details on interpreting IR and NMR spectra are found in your textbook. Your instructor may or may not
ask you to perform this section depending on how your class is structured.
5. To collect an IR spectrum of your product, click on the IR spectrometer located underneath the
laboratory clock and drag the salt plate icon to the flask on the lab bench. A window containing the
IR spectrum for your product should now open. Identify the relevant peaks in the IR spectrum and
record the position and associated functional group for each in the IR table below. The IR spectrum
can also be saved to the lab book for later analysis.
|
IR List position (cm-1) & functional group |
4. |
|
1. |
5. |
|
2. |
6. |
|
3. |
7. |
6. To collect a 1H NMR spectrum of your product, click on the NMR magnet located to the right of the
chalkboard and drag the NMR sample tube to the flask on the lab bench. A window containing the
NMR spectrum for your product should now open. You can zoom into various portions of the NMR
spectrum by clicking and dragging over the desired area. The Zoom Out button is used to zoom back
out to view the full spectrum. Identify all of the peaks in the NMR spectrum and record the chemical
shift, the splitting, and the number of hydrogens for each peak in the NMR table below. The NMR
spectrum can also be saved to the lab book for later analysis.
|
1H NMR Structure: Cl 1-Chloro-1-methyl-cyclohexane |
Peak |
Chemical Shift (δ) |
Multiplicity† |
H‡ |
Peak |
Chemical Shift (δ) |
Multiplicity† |
H‡ |
|
n/a |
1 |
|
|
|
7 |
|
|
|
|
n/a |
2 |
|
|
|
8 |
|
|
|
|
n/a |
3 |
|
|
|
9 |
|
|
|
|
n/a |
4 |
|
|
|
10 |
|
|
|
|
n/a |
5 |
|
|
|
11 |
|
|
|
|
n/a |
6 |
|
|
|
12 |
|
|
|
† Specify the multiplicity as a singlet (s), doublet (d), triplet (t), quartet (q), or multiplet (m).
† Specify the number of hydrogens associated with each peak.
7. Do the IR and NMR spectra you measured and recorded in the tables above confirm that you
synthesized the assigned target compound? Explain.
