Synthesis of Isopentyl Acetate
by Markus Arnoldini
Laboratory Report
Synthesis of
Isopentyl Acetate
O
O
by Markus Arnoldini
1
Synthesis of Isopentyl Acetate
1.
by Markus Arnoldini
Method
Esterification of glacial acetic acid and isopentyl alcohol, using sulfuric acid as
catalyst.
2.
Reaction Equation
O
O
H2SO4
-H2O
+
OH
3.
O
HO
Mechanism
HSO4
H2SO4
O
OH
OH
+
OH
OH
OH
HO
HO
HO
HO
O
H
HO
O
H2SO4
HSO4
HSO4
OH
HO
-H2O
H 2O
O
O
HSO4
O
O
2
Synthesis of Isopentyl Acetate
4.
by Markus Arnoldini
Physical properties of the substances
Isopentyl alcohol [1]
molar weight
density
melting point
boiling point
refraction index
WGK
GK (CH)
R-phrases
HO
S-phrases
88.15 g/mol
0.81 g/cm3 (20 ºC)
-117 ºC
131 ºC (1013 hPa)
1
R 10 (Flammable)
R 20 (Harmful by
inhalation)
R 37 (Irritating to
respiratory system)
R 66 (Repeated exposure
may cause skin dryness or
cracking)
S 46 (If swallowed, seek
medical advice
immediately and show this
container or label)
Glacial acetic acid [1]
molar weight
density
melting point
boiling point
refraction index
WGK
GK (CH)
R-phrases
O
OH
S-phrases
3
60.05 g/mol
1.05 g/cm3 (20 ºC)
17 ºC
116 - 118 ºC (1013 hPa)
1.37 (20 ºC)
1
3
R 10 (Flammable)
R 35 (Causes severe burns)
S 23 (Do not breathe
fumes)
S 26 (In case of contact
with eyes, rinse
immediately with plenty of
water and seek medical
advice)
S 45 (In case of accident or
if you feel unwell, seek
medical advice
immediately. Show the
label where possible.)
Synthesis of Isopentyl Acetate
by Markus Arnoldini
Sulfuric acid (5N) [1]
molar weight
density
melting point
boiling point
refraction index
WGK
GK (CH)
R-phrases
S-phrases
H2SO4
1.15 g/cm (20 ºC)
1
2
R 35 (Causes severe burns)
S 26 (In case of contact
with eyes, rinse
immediately with plenty of
water and seek medical
advice)
S 30 (Never add water to
this product)
S 36/37/39 (Wear suitable
protective clothing, gloves
and eye/face protection)
S 45 (In case of accident or
if you feel unwell, seek
medical advice
immediately. Show the
label where possible.)
3
Sodium Hydrogencarbonate [1]
O
C
HO
O
Na
molar weight
density
melting point
boiling point
refraction index
WGK
GK (CH)
R-phrases
S-phrases
84.01 g/mol
2.22 g/ cm3
270 °C
1
5
-
molar weight
density
melting point
boiling point
refraction index
WGK
GK (CH)
R-phrases
S-phrases
120.37 g/mol
2.66 g/cm3 (20 ºC)
1
-
Magnesium sulfate [1]
MgSO4
4
Synthesis of Isopentyl Acetate
by Markus Arnoldini
Isopentyl acetate [1]
O
O
molar weight
density
melting point
boiling point
refraction index
WGK
GK (CH)
R-phrases
S-phrases
5.
130.19 g/mol
0.87 g/cm3 (20 ºC)
-78 ºC
141 ºC
1
5
R 10 (Flammable)
R 66 (Repeated exposure
may cause skin dryness or
cracking)
S 23 (Do not breathe
fumes)
S 25 (Avoid contact with
eyes)
Experimental accomplishment
7.5 ml of isopentyl alcohol were put in a 100 ml three neck round bottom flask and 10
ml of glacial acetic acid were added. While stirring, 2 ml of H2SO4 were added drop
by drop to the reaction mixture, which was then brought to reflux at 160 °C for 1 h. In
this time, the solution turned dark brown. Then it was cooled down to room
temperature and washed first with distilled water, then with saturated solutions of
NaHCO3 and NaCl and the organic phase was then dried over MgSO4. An amount of
2.788 g pure isopentyl acetate was received by the following distillation.
For the calculation of the yield the molar amount of received product was
divided by the molar amount of reactants used, and then multiplied by 100. This
calculation yields a percentage of 30.435 %:
0.021mol
 100%  30.435%
0.069mol
5
Synthesis of Isopentyl Acetate
6.
by Markus Arnoldini
Experimental setup
Calciumchloride duct
Reflux-cooler
drop flask with H2SO4
Thermometer
three-neck round bottom flask
LaboB ib©
300
50
1500
AN
AN
AUS
AUS 1000
100
o
0 U/min
250
500
C
200
150
750
Seperatory funnel
600
Beaker to collect water phase
800 mL
400
200
6
Synthesis of Isopentyl Acetate
7.
by Markus Arnoldini
Analytical results
Refraction index at room temperature: 1.404
Peaks in IR Spectrum (in cm-1):
2850-3000:
1700-1780:
1420-1480:
1350-1400:
1200-1280:
C-H stretch, aliphatic
C=O
CH2
CH3
C-O
8.
Sources
[1]
[2]
http://ch.chemdat.info/mda/ch/de/
meanings of R-phrases:
http://www.chemie.fu-berlin.de/chemistry/safety/r-saetze_en.html
meanings of S-phrases:
http://www.chemie.fu-berlin.de/chemistry/safety/s-saetze_en.html
[3]
7