20_13_16.html.ppt [Read-Only] PDF Amines do not react with

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by alkaline hydrolysis. An application of Ppt-amino acids to the solid phase peptide synthesis is given. N(C?H?) 3. Ppt-Cl + H?N-CHR-CO?R'. Ppt-NH-CHR-CO?R'.

Ligand Displacement Reactions in Octahedral Complexes- Acid

Base hydrolysis reactions may be defined as the reactions in which a hydroxo complex is formed due to the replacement of a ligand by hydroxyl ion. Base

Chapter 6 Amines and Amides

products of amide synthesis and hydrolysis reactions. • Learn some of the important properties of base. (high pH) acid. (low pH) amine alkylammonium.

20_13_16.html.ppt [Read-Only]

Amines do not react with carboxylic acids to give amides. In basic solution the carboxylic acid product ... Acid-catalyzed amide hydrolysis proceeds via.

HYDROLYSIS 2016.pdf

Hydrolysis reactions are generally enhanced by both acids and bases and three independent reaction mechanisms account for neutral acid and base hydrolysis.

Chapter 5 Carboxylic Acids and Esters

predict the products of ester synthesis and hydrolysis reactions. When they react with each other acids and bases cancel each others properties in a ...

Carbonyl Chemistry (12 Lectures) Aldehydes and Ketones

Carboxylic acid derivatives undergo a cleavage reaction with water (hydrolysis) to yield carboxylic acids. – When the reaction is acid-catalyzed the mechanism

Reaction Mechanism of Transition Metal Complexes – I

Ligand Displacement Reactions in Octahedral Complexes- Acid Hydrolysis. Base Hydrolysis. The general scheme for the ligand displacement reactions in

BIOCHEMISTRY REVIEW Overview of Biomolecules

hydrolyzed by heating in strong acid or strong base. Peptide bonds can be broken by a group of enzymes known as proteases (exo vs. endopeptidase).

20_18_20.html.ppt [Read-Only]

O. H. +. +. Page 8. Hydrolysis of Nitriles. In basic solution the carboxylic acid product is deprotonated to give a carboxylate ion. +. –. RCO. O. HO. +. –.

20.13
20.13

Preparation of Amides

acyl chlorides (Table 20.2) acyl chlorides (Table 20.2) anhydrides (Table 20.3) anhydrides (Table 20.3) esters (Table 20.6) esters (Table 20.6)Preparation of Amides

Preparation of Amides

Amides are prepared from amines by acylation

with: with:

Preparation of Amides

Amines do

Amines do notnotreact with carboxylic acids to givereact with carboxylic acids to give amides. The reaction that occurs is proton amides. The reaction that occurs is proton--transfertransfer (acid (acid--base).base). RCOH RCOHO O +R'R'NNHH22RCO RCOO O +R'R'NNHH33+

If no heat

If no heat--sensitive groups are present, the sensitive groups are present, the resulting ammonium carboxylate salts can be resulting ammonium carboxylate salts can be converted to amides by heating. converted to amides by heating.

Preparation of Amides

Amines do

RCNNHR'HR'O

O +HH22OO

Example

COH COHO O H

H22NN225°C

225°C

+HH22OO (80 (80--84%)84%) CNH CNHO O 20.14
20.14

Lactams

Lactams are cyclic amides. Some are industrial

chemicals, others occur naturally. chemicals, others occur naturally. N NH HO Oe e--Caprolactam*: used toCaprolactam*: used to prepare a type of nylon prepare a type of nylona ab bgg d d e e *Caproic acid is the common name for hexanoic acid. *Caproic acid is the common name for hexanoic acid.

Lactams

Lactams are cyclic amides. Some are industrial

chemicals, others occur naturally. chemicals, others occur naturally.

Penicillin G: a

Penicillin G: a bb--lactam antibioticlactam antibiotica abb CH CH33 CH CH33S S CO

CO22HHO

ON NC

C66HH55CHCH22CNHCNHO

O 20.15
20.15

Imides

Imides have 2 acyl groups attached to the

nitrogen. nitrogen. RC

RCNNCRCRO

OO OR' R'

Imides

The most common examples are cyclic imides.

N NHHO O O O

Phthalimide

N NHHO O O O

Succinimide

Preparation of Imides

Cyclic imides are prepared by heating the

ammonium salts of dicarboxylic acids. ammonium salts of dicarboxylic acids. N NHHO O O

OHOCCH

HOCCH22CHCH22COHCOHO

OO O NH

NH33OCCH

OCCH22CHCH22COCOO

OO O NH NH44+

NHNH44+

+heat heat 20.16
20.16

Hydrolysis of Amides

Hydrolysis of amides is irreversible. In acid

solution the amine product is protonated to solution the amine product is protonated to give an ammonium salt. give an ammonium salt.+ +R'R'NNHH33+ +RCOHRCOHO O RC

RCNNHR'HR'O

O +HH22OOHH++++

Hydrolysis of Amides

In basic solution the carboxylic acid product

is deprotonated to give a carboxylate ion. is deprotonated to give a carboxylate ion. RC

RCNNHR'HR'O

O+ +R'R'NNHH22--RCORCOO O HO

HO++--

Example: Acid Hydrolysis

(88 (88--90%)90%)CH

CH33CHCH22CHCNHCHCNH22O

O CH

CH33CHCH22CHCOHCHCOHO

O H

H22OOH

H22SOSO44

heat heat+ +NHNH44+ +HSOHSO44--

Example: Basic Hydrolysis

(95%) (95%)CH

CH33COKCOKO

O KOH KOHH H22OO heat heat+ +CH

CH33CNHCNHO

O Br BrNH NH22 Br Br Acid Acid--catalyzed amide hydrolysis proceeds viacatalyzed amide hydrolysis proceeds via the customary two stages: the customary two stages: 1)

1)formation of tetrahedral intermediateformation of tetrahedral intermediate

2)dissociation of tetrahedral intermediatedissociation of tetrahedral intermediateMechanism of Acid

Mechanism of Acid--CatalyzedCatalyzed

Amide Hydrolysis

First stage: formation of tetrahedral intermediateFirst stage: First stage: formation of tetrahedral intermediateformation of tetrahedral intermediate RC RCOH OH OH OHN

NHH22+

+HH22OORCRCNNHH22O OH

H++water adds to the

water adds to the carbonyl group of the carbonyl group of the amide amide this stage is this stage is analogous to the acid analogous to the acid-- catalyzed addition of catalyzed addition of water to a ketone water to a ketone

Second stage: cleavage of tetrahedral

intermediateSecond stage: Second stage: cleavage of tetrahedralcleavage of tetrahedral intermediate intermediate +H

H++RCOH

RCOHO O RC RCOH OH OH OHN

NHH22N

NHH44+

Mechanism of formation

of of tetrahedral intermediate tetrahedral intermediate

Step 1Step 1

Step 1

RC RCO O N

NHH22••

•••O

O•

•••++HHH H H H

Step 1Step 1

Step 1

O•

•••++HHH H H H RC RCO O N

NHH22••

quotesdbs_dbs10.pdfusesText_16

[PDF] 20_13_16.html.ppt [Read-Only] Amines do not react with

Preparation of Amides

Preparation of Amides

Preparation of Amides

Amides are prepared from amines by acylation

Amides are prepared from amines by acylation

Preparation of Amides

Preparation of Amides

Amines do

If no heat

Preparation of Amides

Preparation of Amides

Amines do

RCNNHR'HR'O

Example

Example

H22NN225°C

225°C

Lactams

Lactams

Lactams

Lactams

Lactams are cyclic amides. Some are industrial

Lactams are cyclic amides. Some are industrial

Lactams

Lactams

Lactams are cyclic amides. Some are industrial

Lactams are cyclic amides. Some are industrial

Penicillin G: a

CO22HHO

C66HH55CHCH22CNHCNHO

Imides

Imides

Imides

Imides

Imides have 2 acyl groups attached to the

Imides have 2 acyl groups attached to the

RCNNCRCRO

Imides

Imides

The most common examples are cyclic imides.

The most common examples are cyclic imides.

Phthalimide

Phthalimide

Succinimide

Succinimide

Preparation of Imides

Preparation of Imides

Cyclic imides are prepared by heating the

Cyclic imides are prepared by heating the

OHOCCH

HOCCH22CHCH22COHCOHO

NH33OCCH

OCCH22CHCH22COCOO

NHNH44+

Hydrolysis of Amides

Hydrolysis of Amides

Hydrolysis of Amides

Hydrolysis of Amides

Hydrolysis of amides is irreversible. In acid

Hydrolysis of amides is irreversible. In acid

RCNNHR'HR'O

Hydrolysis of Amides

Hydrolysis of Amides

In basic solution the carboxylic acid product

In basic solution the carboxylic acid product

RCNNHR'HR'O

HO++--

Example: Acid Hydrolysis

Example: Acid Hydrolysis

CH33CHCH22CHCNHCHCNH22O

CH33CHCH22CHCOHCHCOHO

H22OOH

H22SOSO44

Example: Basic Hydrolysis

Example: Basic Hydrolysis

CH33COKCOKO

CH33CNHCNHO

1)formation of tetrahedral intermediateformation of tetrahedral intermediate

2)dissociation of tetrahedral intermediatedissociation of tetrahedral intermediateMechanism of Acid