1. Dehydration of 2-Butanol and Dehydrobromination of 2-Bromobutane;
Today:
Expt. #8
Dehydration of 2-Butanol
and
Dehydrobromination of 2-Bromobutane;
Analysis of Products by GC

2. Structure of 2-butanol? How many 2-butanols are there….?
Structure of 2-bromobutane?

3. Dehydration of 2-Butanol
Reaction equation?
Mechanism?
Rate equation?
Energy Diagram?
What intermediate(s) is(are) formed?
What product(s) can we expect?
CHEM 334 Expt 3 Lecture

4. MW 56.11
BP 0.9oC
MW 56.11
BP 3.7oC
MW 56.11, BP -6.3oC

5. B: = Base b Reaction Diagram? Rate equation?
Similarly: leading to 1-butene

6. Use this Set-up: Rubber septum Teflon tube Rubber septum Butenes
K. L. Williamson, Macroscale and Microscale Organic Experiments, 2nd. Edition, D.C. Heath, 1994, p.275
Use this Set-up:
Rubber
septum
Teflon tube
Rubber
septum
Butenes
Collection tube
Reaction tube
H2O
Sand bath

7. Gas Chromatography mixture 1) 2) 3) 4) compounds B A
K. L. Williamson, Macroscale and Microscale Organic Experiments, 2nd. Edition, D.C. Heath, 1994, p.269
Gas Chromatography
With packed column
mixture 1) 2) 3) 4)
compounds B A

8. GC Conditions:
Sample injection volume: mL GC column: 2m x 2mm (I.D.)
Stationary Phase: 0.19% Picric acid on Carbograph 2, 80/100
Oven temperature: 60oC
Moving Phase: Helium Column head pressure: 35 psi or more
Injector temperature: 66oC Detector temperature: 100oC Detector: Thermal Conductivity Detector (TCD)

9. GC Chromatogram of products of the dehydration of 2-butanol reaction3 2
Air Peak 1
Peak Area
Time (min)
r.t. (min)

10. Report Form #8 Part III, Question 2:
What is the maximum volume at STP of the butene mixture that could be obtained by the dehydration of 160 mg of 2-butanol?
STP?
PV = nRT
Units! Use correct R…

11. Next Friday: no classes (Veterans Day) Following Friday Lab Lecture: Exp.9, “Separation and Identification of an Unknown Mixture” (3 lab periods); IR, recryst., mp. s and other techniques you learnt this semester