1. Carboxylic acids: R-COOH, R-CO2H,
Common names:
HCO2H formic acid
CH3CO2H acetic acid
CH3CH2CO2H propionic acid
CH3CH2CH2CO2H butyric acid
CH3CH2CH2CH2CO2H valeric acid
C—C—C—C—C=O
δ γ β α used in common names

2. IUPAC nomenclature for carboxylic acids:
parent chain = longest, continuous carbon chain that contains the carboxyl group  alkane, drop –e, add –oic acid
HCOOH methanoic acid
CH3CO2H ethanoic acid
CH3CH2CO2H propanoic acid
CH3
CH3CHCOOH 2-methylpropanoic acid Br
CH3CH2CHCO2H 2-bromobutanoic acid
dicarboxylic acids:
HOOC-COOH oxalic acid
HO2C-CH2-CO2H malonic acid
HO2C-CH2CH2-CO2H succinic acid
HO2C-CH2CH2CH2-CO2H glutaric acid
HOOC-(CH2)4-COOH adipic acid
HOOC-(CH2)5-COOH pimelic acid

3. salts of carboxylic acids:
name of cation + name of acid: drop –ic acid, add –ate
CH3CO2Na sodium ethanoate
CH3CH2CH2CO2NH ammonium butanoate
(CH3CH2COO)2Mg magnesium propanoate
physical properties:
polar + hydrogen bond  relatively high mp/ bp
water insoluble exceptions: four carbons or less
acidic
soluble in 5% NaOH
RCO2H NaOH  RCO2-Na H2O
stronger stronger weaker weaker
acid base base acid

4. Carboxylic acids, syntheses:
oxidation of primary alcohols
RCH2OH K2Cr2O7  RCOOH
2. oxidation of alkylbenzenes (arenes)
ArR KMnO4, heat  ArCOOH
3. carbonation of Grignard reagents
RMgX CO2  RCO2MgX H+  RCOOH
4. hydrolysis of nitriles
RCN H2O, H+, heat  RCOOH

5. oxidation of 1o alcohols:
CH3CH2CH2CH2-OH CrO3  CH3CH2CH2CO2H
1-butanol butanoic acid
CH CH3
CH3CHCH2-OH KMnO4  CH3CHCOOH
2-methyl-1-propanol` methylpropanoic acid
oxidation of alkylbenzenes (arenes):

6. carbonation of Grignard reagent: R-X RMgX RCO2MgX RCOOH
Increases the carbon chain by one carbon.
Mg CO H+
CH3CH2CH2-Br CH3CH2CH2MgBr CH3CH2CH2COOH
n-propyl bromide butyric acid
Mg CO H+
Hydrolysis of a nitrile:
H2O, H+
R-CN R-CO2H
heat
H2O, OH-
R-CN R-CO H+  R-CO2H
R-X NaCN  R-CN H+, H2O, heat  RCOOH
1o alkyl halide
Adds one more carbon to the chain.
R-X must be 1o or CH3!

7. carboxylic acids, reactions:
as acids
conversion into functional derivatives
a)  acid chlorides
b)  esters
c)  amides
reduction
alpha-halogenation

8. RCO2H + Na  RCO2-Na+ + H2(g) with bases RCO2H + NaOH  RCO2-Na+ + H2O
as acids:
with active metals
RCO2H Na  RCO2-Na H2(g)
with bases
RCO2H NaOH  RCO2-Na H2O
relative acid strength?
ROH < HOH < RCO2H
ionization in water
HA H2O  H3O A-
Ka for carboxylic acids  10-5
Effect of substituent groups on acid strength? Ka
CH3COOH x 10-5
ClCH2COOH x 10-5
Cl2CHCOOH 5,530 x 10-5
Cl3CCOOH 23,200 x 10-5

9. Nucleophilic Acyl Substitution of Carboxylic Acids
Nucleophilic acyl substitution converts carboxylic acids into carboxylic acid derivatives, i.e., acid chlorides, anhydrides, esters and amides.
SOCl2
NH3, D, -H2O
amide
acid chloride
ROH H+ D
-H2O
acid anhydride
ester

10. acid chlorides

11. esters
“direct” esterification: H+
RCOOH R´OH  RCO2R´ H2O
-reversible and often does not favor the ester
“indirect” esterification:
RCOOH PCl3  RCOCl R´OH  RCO2R´
-convert the acid into the acid chloride first; not reversible
amides
“indirect” only!
RCOOH SOCl2  RCOCl NH3  RCONH2
amide

12. Reduction:
RCO2H LiAlH4; then H+  RCH2OH
1o alcohol
Alpha-halogenation: (Hell-Volhard-Zelinsky reaction)
RCH2COOH X2, P  RCHCOOH HX X
α-haloacid
X2 = Cl2, Br2