Synthesis of Isopentyl Acetate PDF

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Chemistry 261 -- Synthesis Experiment Report Form Experiment 9: Synthesis of isopentyl acetate

Name: Carly White

Date: 04/26/18

For Experiment 9, you will keep your notebook as you have previously. You should write your data in your notebook as you collect it. The format shown below may be used. Once all observations are recorded and data is collected, transfer them to this report form. Attach your notebook copy pages and IR and NMR spectra to this report form when submitting your final report. mass of distilled banana oil product: 2.8 percent yield: 0.16

Reaction yield data table

compound

quantity

isopentyl alcohol

1.02

acetic acid

1.98

actual

moles

boiling point

1.1

0.03

2.8

3.19

288oF

0.16

0.19

288oF

isopentyl acetate theory

appearance/odor

Clear, banana aroma

Check out dates & times for instruments: IR: 04/19/18 11:43 AM NMR: 04/17/18 12:06 PM

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Chemistry 261 -- Synthesis Experiment Report Form Experiment 9: Synthesis of isopentyl acetate IR of isopentyl acetate product Wavenumber (cm-1) 2959.8

Sharp

Medium

CHs t r et c h

1739.7

Sharp

Strong

C=O s t r et c h

1366.7

Sharp

Medium

CH2 stretch

1227.8

Sharp

Strong

C-O stretch

Appearance

Intensity

Inference

Isopentyl acetate reference IR data Wavenumber (cm-1) 2966.3

Sharp

Medium

1699.4

Sharp

Strong

1432.2

Sharp

Medium

1234.0

Sharp

Medium

Appearance

Intensity

1

H-NMR isopentyl acetate product

Chemical shift (ppm) 1.62

0.64

2

3.08

0.55

1.10

Quartet

J (Hz) 3

2 nt 3

3

Singlet

N/A

2 nt 0

1.08

1

Multiplet

2

3 nt 2

2.00

0.34

2

Quarter

2

2 nt 3

6.75

0.56

6

Doublet

1

2 nt 3

Integration

#H’s

Multiplicity

Inference

Assignmen t

Compound structure with NMR assignments:

O

H3C

CH3 C

C O

C C

CH3

2

Chemistry 261 -- Synthesis Experiment Report Form Experiment 9: Synthesis of isopentyl acetate

Isopentyl acetate reference 1H-NMR data Chemical shift (ppm) 3.7

0.68

2

2 nt 3

2.9

0.45

1

2 nt 0

2.6

0.56

3

3 nt 2

1.7

1.02

3

3 nt 2

0.9

0.64

2

2 nt 3

Integration

#H’s

Multiplicity

In this lab we learned how to react our products and get our ester product. As we got through the steps of reacting the products and doing the experiment our product smelled like bananas meaning we did the distillation separation correctly. If we hadn’t done it correctly we couldn’t have got the ester and therefore the smell of the ispentyl acetate. We then used our samples and found out the boiling point, and compared it to the literature boiling point we recorded in our tables at the beginning of the lab. We also did the IR spectrum, the NMR, and then used these spectrums to analyze our data. Some of the errors we could have encountered in this experiment is not doing the distillation correctly. If some of the product escaped we would not have the correct ratio. We could also read the spectrums wrong, this would lead to us drawing and labeling our structure for our compound wrong. We could also have done the percent yield calculations wrong. Another source of error would be reading the temperature wrong on the thermometer. If we missed when it started boiling the temperature we recorded could be wrong. This lab is important as it gives us practice doing distillation and then reading and recording data from our spectrum. This is important in determining how pure our substance was and that would determine how well we separated the products out in our distillation. We then need it to use that information to draw the structure of our compounds. It is important to be able to know how to draw the compounds from the spectrums because sometimes if a researcher doesn’t know what the product is they can use it to figure out what compound they have based on the spectrums. Practicing how to prepare and read the spectrums is very important.

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Chemistry 261 -- Synthesis Experiment Report Form Experiment 9: Synthesis of isopentyl acetate 1. The Fischer esterification reaction is equilibrium. Give two things you did in this experiment to drive the reaction toward the ester product. Explain how each action drives the reaction toward the ester. 1. We did a distillation, which is how we got our product as it separates our products. 2. We did this twice so our compound was a pure separation of the ester.

2. What is the point of extracting the reaction mixture with 5% sodium bicarbonate Why is it necessary to ensure all connections are tight and with O-rings when the ester is distilled? It is important because if there is no O-ring and the cap is not on tight then the ester will escape and we will not get any in the flask. 3. Give one example of a Fischer esterification in real life. An example would be in fruits, esters are made in the fruits, which give them certain smells. These smells may be used to attract pollinators or other animals so they can eat and disperse the seed. Plants carry out this type of reaction.

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