Exercise No. 10
Reactions and Preparations of Carboxylic Acid and Derivatives
1. By means of a suitable reaction, show how each of the ff. compounds can be prepared
from propionic acid. More than one step may be required.
a. ethyl propionate
H+
+ CH3 -CH2-OH
+ H2O
ethyl propionate
Ethanol
Water
b. propionyl chloride
+ SOCl2
+ SO2 + HCl
Hydrochloric acid
propionyl chloride
Sulfur dioxide
c. N-methyl propionamide
+ SOCl2
+ SO2 + HCl
Hydrochloric acid
propionyl chloride
+ H2N-CH2CH3
Sulfur dioxide
CH3-CH2-C-NH- CH3
O
N-methyl propionamide
propionyl chloride
d. propionic anhydride
+
NaOH
+ HCl
Cl
propionyl chloride
propionic anhydride
Hydrochloric acid
e. methyl propylamine (CH3NHCH2CH2CH3)
+
H2N-CH3
NH - CH3
N-methylpropanamide
LiAlH4
NH - CH3
H20
methylpropylamine
2. Write equations to show the reaction of propanoyl chloride with:
a. Water
+ HCl
+ H 2O
Hydrochloric acid
propionic acid
propanoyl chloride
b. Ammonia
+ NH3
+ NH4Cl
NH2
Ammonium chloride
propionamide / propanamide
c. Aniline
O
NH-C-CH2-CH3
+
+ HCl
N-phenylpropanamide
Hydrochloric acid
d) sodium acetate
+
+ NaCl
O
Sodium chloride
acetic propanoic anhydride
d. isopropyl alcohol
CH-CH3
+
CH3
+ HCl
Hydrochloric acid
isopropyl propanoate /
isopropyl propionate
f.
benzene + AlCl3
+
+ HCl
AlCl3
Hydrochloric acid
propiophenone
e. dimethylamine (CH3-NH-CH3)
+
+ HCl
Hydrochloric acid
N,N-dimethylpropionamide
3. By means of a series of equations outline a synthesis for each of the ff. compounds from
the indicated starting material. You may use any other reagents needed.
a. ethyl butanoate from n-butyl alcohol
KMnO4
n-butyl alcohol
butanoic acid
H2SO4
+
ethyl butanoate
ethanol
butanoic acid
b. propionyl chloride from n-propyl alcohol
KMnO4
+
+
PCl3
n-propyl alcohol
propanoic acid
propionyl chloride
c. benzamide from toluene
+ SOCl2
toluene
benzoyl chloride
benzoic acid
NH3
benzoyl chloride
benzamide
H3PO4
phosphoric
acid
d. sec-butyl acetate from 2-butene
O
O3
CH3-CH=CH-CH3
CH3-CH
O
CH-CH3
(CH3)2S
+
O
acetaldehyde
H2CrO4
H2SO4
+
sec-butyl acetate
2-butanol
acetic acid
acetaldehyde
e. n-butyric anhydride from n-butyl alcohol
KMnO4
n-butyl alcohol
NaOH
+
Butanoic acid
Butanoic acid
butanoyl chloride
n-butyric anhydride
4. Predict the products (if any) of the reaction of each of the ff. reagents with benzoic acid.
a. NaOH
+
NaOH
O-Na+
+
H20
water
sodium benzoate
b. LiAlH4
+
LiAlH4
benzoyl alcohol
c. PCl5
+
+
PCl5
benzoyl chloride
HCl
+ POCl
3
hydrochloric acid
phosphorus oxychloride
d. NaBH4
+
NO REACTION
NaBH4
e. CH3OH
+
O-CH3
CH3OH
+
H2O
water
methyl benzoate
f. H2, Pt, 1 atm, room temp.
H2
NO REACTION
Pt, 1 atm
g.
SOCl2
+
+
SOCl2
SO2
+
HCl
sulfur dioxide
benzoyl chloride
h.
hydrochloric acid
conc. HCl
conc. HCl
NO REACTION
5. Write the products of the following reaction sequences.
a) C6H5-CH3
i.
Br2, light
Br2, light
C6H5-CH3
ii.
+
HBr
NaCN
NaCN
C6H5-CH2Br
iii.
C6H5-CH2Br
benzyl bromide
benzyl cyanide
C6H5-CH2CN
sodium bromide
+ NaBr
H2O, heat
H2O,heat
C6H5-CH2CN
-
C6H5-CH2-C- O NH4 +
O
ammonium benzyl enolate
iv.
NaOH
NaOH
-
C6H5-CH2-C- O Na +
C6H5-CH2CN
+ NH3 + H2O
O
sodium benzyl enolate
b)
ammonia
water
OH
H+, heat
i.
OH
H+
+ H2O
heat
water
cylohexene
ii.
O3
O
CH
O3
CH
O
O
cylohexene ozonide
iii.
Zn, H2O
O
O
CH
O
CH
C - CH2- CH2- CH2- CH2 -C
Zn
O
O
H
H2O
H
hexanedial
iv.
H2Cr2O7
O
O
O
H2Cr2O7
O
C - CH2- CH2- CH2- CH2 -C
C -CH2- CH2- CH2- CH2- C
OH
H
OH
H
adipic acid / hexanedioic acid
c) C6H5-CH2Br
i.
Mg/ dry ether
MgBr
Mg
Dry ether
ii.
benzyl magnesium bromide
HCHO
OH
CH2O
MgBr
C- H
H
iii.
2-phenylethanol
KMnO4
O
OH
KMnO4
C-H
C -OH
H
phenylacetic acid
d) benzene
i.
CH3I, AlCl3
CH3
AlCl3
+
+ CH3I
HI
hydroiodic acid
toluene
Ii. KMnO4
CH3
KMnO4
benzoic acid
ii.
SOCl2
SOCl2
+
SO2
+ HCl
sulfur dioxide hydrochloric acid
benzoyl chloride
iii.
benzene, AlCl3
AlCl3
+
benzophenone
e) CH3CH2CHO
i.
CH3MgBr
OH
CH3MgBr
CH3 - CH2 -CH -CH3
2-butanol
ii.
H2Cr2O7
O
OH
H2Cr2O7
CH3 - CH2 -CH -CH3
CH3 - CH2 -C -CH3
2-butanol
2-butanone
iii.
I2, base
O
O
CH3 - CH2 -C -CH3
I2
Na+
CH3 - CH2 -C -O
Base [NaOH]
+
CHI3
Iodoform
Sodium propionate
6. Write the equations showing the reactions of propanoic acid with:
a. thionyl chloride
+
+ SO2 + HCl
SOCl2
propionyl chloride
b. methanol
+
+ H2O
CH3OH
O-CH3
methyl propionate
c. Ammonia
water
+
NH3
-
NH4 +
ammonium propionate
7. Write equations to show how each of the ff. compounds could be converted into benzoic
acid.
a. Bromobenzene
MgBr
Mg
CO2
Dry ether
H+
+ MgBr(OH)
OMgBr
dry ice
benzoic acid
bromobenzene
b. Toluene
KMnO4
∆(Heat)
benzoic acid
toluene
c. Benzonitrile
+ H2O
H+
+ NH4
benzoic acid
benzonitrile
d. benzyl alcohol
KMnO4
benzyl alcohol
benzoic acid
8. Write equations to show each of the ff. compounds could be converted to n-butyric acid.
a. n-butyl alcohol
KMnO4
N-butyric acid
b. n-propyl alcohol
Br + H2O
+ HBr
Br Mg
MgBr CO2
COOMgBr
COOMgBr
N-butyric acid
H+
9. Write the equations to show how isobutyric acid could be converted to each of the
following using needed reagents
a. ethyl isobutyrate
H+
+
+ H2O
ethyl isobutyrate
b. isobutyryl chloride
+ PCl3
isobutyric acid
+ H3PO4
c. Isobutyramide
isobutyryl chloride
+ SO2 + HCl
+ SOCl2
isobutyric acid
NH3
+ NH4Cl
isobutyryl chloride
isobutyramide
d. magnesium isobutyrate
O-Mg+
+ MgCO3
isobutyric acid
+ CO2 + H2O
magnesium isobutyrate
e. isobutyl alcohol
4 (CH3)2CHCOOH + 3 LiAlH4
ether
+
[(CH3)2CHCH3O]4AlLi + 2LiAlO2 + 4H2 H
(CH3)2CHCH2OH
isobutyl acid
isobutyric acid
10. Write the balanced equations, naming all organic products (if any) for the reaction of –
butyryl chloride with:
a. H2O
+ HCl
+ H2O
butanoic acid
Hydrochloric acid
b. isopropyl alcohol
+
+ HCl
isopropyl butanoate
c.
Hydrochloric acid
p-nitrophenol
+ HCl
+
Hydrochloric acid
O
NO2
p-nitrophenyl butyrate
d. Ammonia
+ NH4Cl
+ NH3
Butanamide/ butyramide
ammonium chloride
e. toluene, AlCl3
+
AlCl3
+ HCl
Hydrochloric acid
COCH2CH2CH3
1-(4-methylphenyl)butan-1-one
f. nitrobenzene, AlCl3
+ HCl
AlCl3
+
Hydrochloric acid
1-(4-nitrophenyl)-1-butanone
11. An unknown ester C6H12O2 was hydrolyzed with water and acid to produce an acid X and
an alcohol Y. Oxidation of Y with chromic acid produced X. What was the structure of
the original ester. Write the equations for all the reactions that occur.
RCOOCH2R
H3O+
RCOOH
+ R’OH
H2CrO4
Ester
propyl propanoate
H3O+
H2CrO4
propanol (Y)
propanoic acid (X)