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Derivative of carboxylic acids
Acid halide )1(
Nomenclature
oyl halide ‫ بـ‬alkane ‫ من اسم‬e ‫ باستبدال حرف‬-
alkanoyl halide
Alkane
yl chloride ‫ بـ‬ic ‫ أو من اسم الحمض باستبدال‬-
Preparations
Chemical reactions
Reaction of acid chloride with R-MgX
Hell volhard zelinski
H2 O
H3C C C Cl
propionyl chloride
Cl2
P
)2( Acid anhydride
H
H3C C
Cl
O
C Cl
anhydride ‫ التسمية تتم بذكر اسم الحمض متبوعاً بكلمــة‬-
Preparation
( 1 ) From acid chloride
)2( From acetylene
)3( From ketene
‫‪Chemical reactions‬‬
‫‪)3( Amide‬‬
‫ التسمية تتم بذكر اسم ‪ alkane‬محذوفاً منه حرف ‪ e‬واستبداله بـ ‪ amide‬أو اسم‬‫الحمض محذوفاً منه ‪ oic‬واستبدالها بـ ‪amide‬‬
Preparation of amides
)1( From acid chloride, anhydride, ester
)2( From nitriles
) 3 ( From ammonium salt
Chemical reactions
) 1 ( Hydrolysis
) 2 ( Hofmann degradation of amide
Q. Convert acetic acid to methyl amine
‫اإلجابـة‬
) 3 ( Dehydration
( 4 ) Action of nitrous acid
‫‪)4( Esters‬‬
‫ التسمية تتم كاآلتي‪-:‬‬‫‪ -1‬ذكر اسم `‪R‬‬
‫‪ -2‬ذكر اسم الحمض محذوفاً منه ‪ -ic‬ومضافاً اليه ‪ate‬‬
Ortho ester
Fats esters
.e.g
Preparation
4) CH3COOAg + C2H5Br
CH3COOC2H5 + AgBr
5) RCOOH + CH2N2
RCOOCH3 + N2
6) H2C C O + C2H5OH
CH3COOC2H5
7) CHCl3 + C2H5ONa
CH(OC2H5)3
Reactions of esters
Reaction with Grignard to form t-alc
Mechanism
Claisen condensation of ester
Mechanism
Substituted products of monocyclic acids
1. Halogenated acids
.‫ على حسب موقع الهالوجين‬δ ، γ ، β ، α ‫تقسم الى‬
Preparation of α-halo acid
1. Hell-Volhard-Zelinski reaction
Iodo derivative can be prepared as follow
2. From α-hydroxy acid
preparation of β-halogenated acid
alkene ‫الحظ اإلضافة تتم عكس قاعدة ماركنكوف في حاله اتصال سلسله‬-COOH ‫أو‬
‫بمجموعه الدهيد أو كيتون‬
2. From hydroxy acid
Preparation of γ-Halogenated acid
CH2=CH-CH2COOH + HBr
BrCH2CH2CH2COOH
Reactions of Halogenated acid
Effect of NaOH on Halogenated acids
1. Effect of NaOH on α-Halo acid
ClCH2COOH +NaOH
HOCH2COONa
2. Effect of NaOH on β -Halo acid
ClCH2CH2COOH +NaOH
CH2=CHCOOH
Acrylic acid
3. Effect of NaOH on γ – and δ-Halo acid
(B) Hydroxy acids
OH ‫ على حسب موقع‬δ ، γ ، β ، α ‫ تقسم الى‬-
‫ أسماء يجب حفظها‬-
Preparation of Hydroxyacids
1) Preparation ofα-hydroxy acid
1. From halogenated acid
2. From aldehyde or ketones
O
CH3CH +HCN
OH
CH3CH-CN
H3O
+
OH
CH3CH-COOH
Lactic acid
2) Preparation of β-hydroxy acid
Reformatsky reaction
3) Preparation of γ & δ-hydroxy acids
Chemical reactions
1) Action of heat
1- α-hydroxy acid
2- β-hydroxy acid
3- γ-hydroxy acid or δ-hydroxy acid
2) Action of PCl3
3) Reduction with HI
(C) Amino acids
Preparation of amino acids
(2) Streacker’s synthesis
(3) Gaberial synthesis
Gaberial synthesis can be used for synthesis amino acids & amines
a) For synthesis of amino acids e.g. Glycine
Question: Convert Phthalimide to Glycine ?
Reaction of amino acids
1) Amphoteric character of amino acid
Amino acids are amphoteric because it contains both acidic –COOH
thus it is present in an inner salt (B) which is , group and basic group –NH2
Zeitter ion called
In acidic medium it exist in (C)
In basic medium it exist in (A)
Isoelectric point of amino acid
It is the pH at which the amino acid exists as the inner salt (B)
2) Reactions of amino group
a) Conversion to hydroxy acid
b) Acetylation
3) Effect of heat
1- α-amino acid
2- β-Amino acid
3- γ- Amino acid or δ- Amino acid
Dicarboxlic acids
Examples
General methods of preparation of dicarboxylic acids:1.oxidation of glycols:
2. hydrolysis of dinitriles:
Special methods:
Oxalic acid:
1.Heating sodium formate:
2. By passing dry CO2 over sodium metal heated to 360°
3. By the oxidation of sucrose with conc. HNO3 in
the presence of V2O5.
Malonic acid:
Preparation of diethylmalonate:
Diethylamalonate is much more important than the acid.
Succinic acid can also be prepared by reduction of malic
and tartaric acids with HI and red P.
Glutaric acid:
1. By the action of methylene iodide on ethylmalonate.
2. Oxidative fission of cyclopentanone with nitric acid in
the presence of V2O5.
Adipic acid:
1.Catalytic air oxidation of cyclohexane obtained from petroleum.
2. Oxidative fission of cyclohexanol or cyclohexanone
by nitric acid at 30-40°.
Phthalic acid:Is prepared by the catalytic oxidation of naphthalene or o-xylene
Reactions:
1.Dicarboxylic acids show the same characteristic reactions
as monocarboxylic acids.
2. Effect of heat
b) Malonic acid : acids of the type
where X is strongly electron attracting
(e.g. –COOH, -CONH2, -COOR, -COR, -CHO, -CN, -NO2)
lose CO2 even on mild heating.
(C) Succinic and glutaric acids yield the corresponding
cyclic anhydrides.
Heating adipic acid with Ba(OH)2, MnCO3 or the O2 give
cyclopentanone.
(e) Phthalic acid form phthalic anhydride on heating at 200°
Unsaturated and substituted acids
Nomenclature:
Ordinary methods of nomenclature can be applied to substituted acids,
but many acids have trival names.
Preparation:
1.Maleic acid:
(a) Rapid heating of malic acid to about 250°.
(b) Catalytic air oxidation of benzene at 400°.
(c) Air oxidation of crotonaldehyde.
2. Fumaric acid and malic acid:
3. Tartaric acid:
)1( Cyanohydrin synthesis from glyoxal :
(2) from dibromosuccinic acid
(3) Oxidation of maleic acid with neutral KMnO4
4. Citric acid:
1- From 1,3-dichloroacetone:
1,3-Dichloroacetone can be prepared by treating glycerol
with HCl followed by oxidation.
Reactions:
1- Addition of HX to α,β-unsaturated acids give β-haloacids.
2- Diels-Alder Reaction.
3- Heating tartaric acid gives pyruvic acid.
4- Heating citric acid to 175oC gives aconitic acid.
5. Reduction of tartaric acid with HI.
6- Citric acid loses water and CO on treatment with H2SO4
giving acetone dicarboxylic acid which on strong heating
decomposes into acetone and CO2.
Preparation of urea:
1. Urea may be obtained by the action of ammonia on ethyl carbonate
of phosgene
2- Partial hydrolysis of cyanamide with dilute H2SO4 at 70.
3-
Reactions of urea:
1- Urea is a very weak base. By accepting a proton on the oxygen atom,
urea forms a positive ion which is stabilized by resonance.
2- Hydrolysis: urea undergo hydrolysis in acid
or alkaline solutions or in water in the presence
of the enzyme urease present in soya beans.
3. Reaction with nitrous acid
4. reaction with acid chlorides
5- Reaction with hypobromite.
6- Reaction with malonic ester (Synthesis of barbituric acid).
Barbital, 5, 5-diethylbarbituric acid, is hypnotic. For their
synthesis a disubstituted malonic ester is condensed
with urea.