carboxylic acid and carboxylic acid derivatives carboxylic acid and carboxylic acid derivatives dr....
TRANSCRIPT
Carboxylic acidand carboxylic acid
derivatives
Dr. Nabila Al Jaber
Carboxylic acid R-COOH Ar-COOH Aliphatic (carboxylic cid) aromatic (benzoic acid)
1) replace ane by -ic acid
Nomenclature :
Common IUPAC Formula No. C
Formic acidAcetic acidPrpionic acidButyric acidvaleric acid
Salicylic acid
Benzoic acid
Methanoic acidEthanoic acidPrpanoic acidButanoic acidPentanoic acid
2-hydroxy ben. a
HCOOHCH3COOH
CH3CH2COOH
CH3(CH2)2COOH
CH3(CH2)3COOH
12345
OH
COOH
COOH
2) Longest continuous chain
CH3CH2CHCH2CH2COOH 4-Methyl hexanoic acid CH3
C-C-C-C-C-COOH
CH3CH2CHCH2CH2COOH γ-Methyl hexenoic acid CH3
CH3-CH-CH-COOHCH3CH3
commmone: -- Dimethyl butyric acidIUPAC: 2,3-Dimethyl butanoic a
CH3-CHBr-CHCl-CO2H
3-Bromo-2-chlorobutnoic acid
3) In cyclic ring ------ cycloalkane carb. a'
COOHCOOH
COOH
cyclopropanecarb.ac.
cyclobutanecarb.ac.
cyclopentanecarb.ac.
cyclohexanecarb.ac.
COOH
COOH 2-Cyclohexene carboxylic acid3
5) Aromatic acid by common name
CO2H CO2H
(comm.) Phthalic a'
(comm.) Terephthalic a'
CO2H
CO2H
CO2H
benzoic acid
OH
CO2H
Salycilic acidO- hydroxy benzoic acid
CH2CH2COOH
3-Phenyl-propionic acid
OH
HOOC
Hydroxy-phenyl-acetic acid
Physical properties
1] They form hydrogen 2] comp. 1-7 soli in H2O . 3] mor than 7 carbon less soli. (bec. R
increased)4] Aromatic acids insoluble. In H2O5] BP. Acid > Alcohol
Deac. gps inc. acidity Acti gps dec. acidity
COOH
NO2NO2
COOH
NO2
COOH COOH
CH3
> > >
inc. acidity
OHCOOH COOH OH
inc acidity
HCOOH > CH3COOH > CH3CH2COOH > CH3 CH2 CH2COOH
More acidity
Substitution with halogen :
CH3CH2COOH < CH2Cl-CH2COOH (more acidic)
CH3CH2COOH < CH2ClCOOH < CHCl2COOH < CCl3COOH
More acidity
Preparation of carboxylic acid
1] Oxidation
a) 1 alcohols & Aldehydes
CH3CH2OH KMnO4 / H+ CH3CHO CH3COOHheat
CH2OH CHO COOH
KMnO4 / H+
or K2Cr2O7 /H+
heat
Preparation of carboxylic acid
RCH2OH
Cu / Heat
or KMnO4 / H+
or CrO3 / pyridineR-CHO
K2Cr2O7 / H+RCOOH
b) of alkyl benzene
CH3 COOH
KMnO4 / H+
or K2Cr2O7 /H+OCH3 OCH3
COOHKMnO4 / H+
or K2Cr2O7 /H+
CH3
NO2 NO2
COOH
KMnO4 / H+
or K2Cr2O7 /H+
CH2CH2CH3
2)Hydrolysis of nitriles
RCN +H2O
R-COOH
RCOO
R-X + NaCNheat
OH
H+
(K,Na,..)
RCH2NH21)Li AL H4, ether
2)H3O or H2 / Pt amine
(K<Na..)
CH3CH2Cl1)NaCN
CH3CH2CN + H2O 2) Hheat
CH3CH2CO2H
CH2Cl
1)NaCN
CH2CN
2) H
heat
CH2CO2H
+ H2O
3] Carbonation of Grignard reagent:
R-Mg X R-COOMgX H3O RCOOHCO21) 2)
CH3-Mg Br CH3-COOMgBr2) H3O
CH3COOH+ Mg(OH)Br
1)CO2
Mg Br COOH
1)CO22) H3O+
Preparation of carboxylic acid
• Hofmann Reaction
• Collb’s Reaction
O
+ NaOHI2
OH
O
+ CHCl3
Reactions of acids
1)Salt formation:
it react with strong base & we can use CaOH, NaOH or KOH
RCOOH + KOH RCOOK + H2O
RCOOH + NaOH RCOONa + H2Osodi. acetate
reaction with weak base
RCOOH + NaHCO3 RCOONa + CO2 + H2O
Sodium bicarb. Can be used to distinguish between carboxylic acid and phenols
OH
+ NaHCO3NO reaction
Reactions of acids
2) Formation of Easter:
RCOOH R'-OH / H+heat R-COO-R' + H2O
OH
COOH
CH3CH2OH OHCOOC2H5H+ / heat
3) Formation of amide:
RCOOH NH3 or R-NH2 ,heat R-CONH2
CH3COOH heatCH3-CONH2
NH3 ,
Reactions of acids
4) Formation of acid anhydride:
2 RCOOH R-C-O-C-RO O
2 CH3CH2COOH CH3CH2-C-O-C-CH2CH3O OH2SO4
H2SO4
5) Formation of acid chloride:
2 RCOOH SOCl3 PCl3 R-C-ClO
2 CH3COOHO
or PCl5
SOCl3 PCl3or PCl5
CH3-C-Cl
,
,
2
2
Reactions of acids
Reactions of acids
Addition anti marco.
OH
O
HBrH2OOH
O
OH
O Br
HH
OH
H+
Nomenclature of carboxylic acid derivatives
When Oxygen of Carboxylic acid is replaced with Nu.------ Carb. a' deriv
OH
O
R
Nu
O
R Nu
O
Ar
R Cl
O
R OR'
O
R N
O OO
R-C-O-C-R
Acid chl. Ester AmideAcid anhydride
R O-(K or Na)
O
Salts
When Oxygen of Carboxylic acid is replaced with Nu.------ Carb. a' deriv
1] Salt:
H3C O- Na
O
Com. Sodium acetate
IU. Sodium etanoate
from Acet.a'.
from Ethan.a'.h
, K
2] Acid chloride
Cl
O
CH3CH2
(Com.) Proanyl chloride from propanoic a'(I) Propionyl chloride from propionic a'
I
Com.
Cl
O
Benzoyl chloride
3] Ester:The alkyl gp. Named 1st then the name of parent acid with ending –ate in place of -ic acid
OCH2CH3
O
CH3(Com.) Ethyl ethanoate from ethanoic a'
(I) Ethyl acetate from acetic a'
I
Com.
OCH3
O
H (Com.) Methyl formate from formic a'(I) Methyl methanoate from mthanoic 'a
O-CH3
O
Methyl benzoate Methyl salisylate
OCH3
O
OH
O-C-CH3
O
CH2-O-C-CH3
O
(I) Phenyl ethanoate(Com.) Phenyl acetate
(I) Benzyl ethanoate(Com.) Benzyl acetate
O-CH=CH2
O
CH3Vinyl acetate
4]Amides:
-oic acid or -ice a' by –amide .f 1 or 2 subst. on nitrogen we say N-subs. or N,N-disubs. (sub. Name 1st )
NH2
O
R NH2
O
ArOr
O
C-NH2Benzamide
NH2
O
CH3CH2Propanamide
C-NCH3
O
CH3C-N
CH3
C2H5
O
(I) N,N-Dimethyl benzamide(I) N,Ethyl-N-methyl benzamide
4] Acid anhydride:
replacing -acid with anhydride
O
C-O-C-R
O
R
O
C-O-C-R
O
Ar
O
C-O-C-CH3
O
CH3 Ethanoic anhydride
O
C-O-C-CH2CH3
O
CH3CH2(I) Propanoic anhydride (C) Propionc anhydride
R-CO-Cl > R-(CO)2O-R > RCO2R > RCO2H > RCONH2
Acid chloride Acid anhydride Ester Acid Amide
Order of reaction:
O
OO
Benzoic acid anhydride
O
O
O
Dihydro-furan-2,5-dione
Succinic anhydride
AMIDES
ESTERS
ANHYDRIDES
Overview Reaction
Reactions of acid derivatives
a) Acid chlorides:
R-C-ClO
R-C-OH + HClO
R-C-OR'O
R-C-NH2
O
R-C-NHR'O
R-C-NO
H2O/ H+
R'OH
NH3
R'NH2
R'2NH
+ HCl
+ HCl
+ HCl
R'
R' + HCl
Reduction:
Cl
O
R
1) Li Al H4 / ether
2) H3OR-CH2OH
B] Acid anhydride:
R-C-O-C-RO
R-C-OHO
R-C-OR'O
R-C-NH2
O
R-C-NHR'O
R-C-NO
H2O/ H+
R'OH
NH3
R'NH2
R'2NH
+ RCOOH
+ RCOOH
+ RCOOH
R'
R' + RCOOH
O
acid
Ester
Amid
2
O
O
R
O
ROH
COOH
O CH3
O
+CH3-COOHCOOH
acetyl salisilic acid + acetc acidCH3CH3
Reduction:
1) Li Al H4 / ether
2) H3O2 R-CH2OHO
O
R
O
R
C] Esters:
RCOOR' + H2O RCOOH + R'OHH+
RCOOR' + R''OH RCOOR'' + R'OHH+
RCOOR' + NH3 RCONH2+ R'OHH+
Reduction:
RCOOR' RCH2OH+ R'OH1)Li Al H4 / ether
2) H3O
CH3CH2CH2OH+ CH3OH1)Li Al H4 / ether
2) H3OCH3-CH2COOCH3
R-C-OO-R' 1) 2 R'' Mg X
2 ) H3O / H+R-C-R''
OH
R''
+ R' OH
d] Amide:R-C-NH2
OR-C-OH + NH3
O
R-C-NH2
OR-C-ONa + NH3
O
+ H2OH+
NaOH / heat
Reduction:
R-C-NH2
O
R-C-NHR'O
1) Li Al H4 / Ether2) H3O
1) Li Al H4 / Ether
2) H3OR-CH2NHR'
R-CH2NH2
R-C-NO 1) Li Al H4 / Ether
2) H3OR-CH2NR'2
R'
R'
Dehydration:O
P2O5
- H2OR-CN nitrileR-C-NH2
Hoffman degradation:
RCH2-C-NH2
O Br2/ NaOH
or NaOBrR-CH2NH2
OBr2/ NaOH
CH3NH2CH3-C-NH2