DCC

1. Advanced Organic Chemistry
Synthetic reagent
Presentation
Dicyclohexylcarbodiimide(DCC)
S. Maheen Abdul Rahman,
M. Pharm.,
Department of Pharmaceutical
Chemistry

2. Table of contents:
Introduction
Properties
Preparation
DCC involving chemical reaction
Application

3. Introduction
N,N'-Dicyclohexylcarbodiimide:
 N′Dicyclohexylcarbodiimide (DCC or DCCD) is
an organic compound with the chemical formula (C6H11N)2C.
 Sheehan and Hess introduced the use of
dicyclohexylcorbodiamide (DCC) as a coupling reagent for
the preparation of amide bonds in 1955 . And DCC has been
used since then for peptide synthesis.

4. Properties
 DCC is a waxy white solid with a sweet odor. Its primary use
is to couple amino acids during artificial peptide synthesis.
 The low melting point of this material allows it to be melted
for easy handling.
 It is highly soluble in dichloromethane, tetrahydrofuran,
acetonitrile and dimethylformamide but insoluble in water.
 The melting point is 30-35oC
 The boiling point is 122-124oC
 And the molecular weight of DCC in 206.33 g/mol.

5. Prepration
Dicyclohexylcarbodiimide may be prepared by any of the
methods given below:
1. By the Oxidataion of N,N’- dicyclohexylthiourea eith
mercuric oxide(Mg2O)
2. By the Dehydration of Dicyclohexylurea with
p- toluene sulphonyl chloride in hot pyridine

6. DCC involving Chemical reaction:
1. Synthesis of Esters: The esterification of acids with primary or
secondary alcohols promoted by DCC
 Mechanism of Reaction: This reaction is catalysed by acids. The acid
in first step reacts with the reagent to form a compound I which is a
good leaving group. Subsequent reaction of compound I with alcoho in
second step to gives ester with the removal of dicyclohexylurea.

7. 2. Synthesis of amides: The amides not directly obtained by reacting acids with
amine, here the reagent first convert the acid to its anhydride form, which is
further reacts with amine to produce amide.

8. 3. Synthesis of Ethers: A mixture of phenol, alcohol and the reagent on
prolonged heating under the pressure to produce aryl alkyl ether.
4. Synthesis of Acid anhydride: The reagent gives excellent yield of acid
anhydride from carboxylic acids
And also this reagents to produce symmetrical anhydrides from N-
substituted amino acids(Phenylalanine derivatives)

9. 5. Synthesis of Diacyl peroxide: Diacyl peroxide can be synthesized
by the treatment of carboxylic acids with hydrogen peroxide under
the mild condition with DCC
6. Synthesis of lactones: [ DCC in pyridine ] has been found to be a
better reagent for the synthesis of lactone by the lactonization of γ-
hydroxy acids. And also this method has been widely used in the
synthesis of Reserpine.

10. 7. Synthesis of Lactams: Lactams are cyclic amides. Β- Lactams are
highly strained ring, sensitive to acids while most reagents for amide
linkage involves strongly acid reagents. This caused a serious
problems in penicillin synthesis. However , the difficulty was
overcome by using DCC for the amide linkage.
Di isopropyl carbodiimide also has been found to be a better
reagent for amide ring formation but it is very mild reagent!
8. Synthesis of Peptides: The amino acids in the amino function has
been protected by Pthalyl [C6H4(CO)2] or Carbobenzoxy
[C6H5CH2–O–C=O] condense with amino acid esters in the
presence of DCC at room temperature to gives Peptides.

11.  After hydrolysis of product the protecting group (Pthalyl group)
which is removed by hydrazine ( like Gabrial synthesis)
 Pthalyl and Carbobenzoxy groups are used as a protecting groups ,
since they can be easily substitutesd and easily removed after
synthesis of particular products by Hydrogenolysis with [Pt + H2].

12. Application
N,N'-Dicyclohexylcarbodiimide is a carbodiimide used to
couple amino acids during peptide synthesis which is
done by Sheehan and Hess in 1955.
N,N'-Dicyclohexylcarbodiimide is used as a dehydrating
agent for the synthesis of amides, ketones , nitriles as well
as in the inversion and esterification of secondary
alcohols.
DCC has been foun to be very useful reagent for the
synthesis of Lactam ring (β- lactum in penicillin)

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