A carbodiimide is a functional group consisting of the formula N=C=N. Carbodiimides hydrolyze to form ureas, which makes them rarely found in nature. In organic chemistry functional groups are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules. ... Hydrolysis is a chemical process in which a molecule is cleaved into two parts by the addition of a molecule of water. ... Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO. Urea is also known as carbamide, especially in the recommended International Non-proprietary Names (rINN) in use in Europe. ...

Carbodiimide formation

Carbodiimides are formed by dehydration of ureas or from thioureas. Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO. Urea is also known as carbamide, especially in the recommended International Non-proprietary Names (rINN) in use in Europe. ... Thiourea is related to urea, where an oxygen atom is replaced by a sulfur atom. ...

Uses of carbodiimides

In synthetic organic chemistry, compounds containing the carbodiimide functionality are dehydration agents and are often used to activate carboxylic acids towards amide or ester formation. Additives, such as N-hydroxybenzotriazole or N-hydroxysuccinimide, are often added to increase yields and decrease side reactions. Organic synthesis is the construction of organic molecules via chemical processes. ... Organic chemistry is the part of chemistry concerned with the composition, structure, properties, reactions and synthesis of organic compounds. ... Structure of a carboxylic acid The 3D structure of the carboxyl group A space-filling model of the carboxyl group Carboxylic acids are organic acids characterized by the presence of a carboxyl group, which has the formula -C(=O)-OH, usually written as -COOH. In general, the salts and anions... Amide functional group In chemistry, an amide is one of two kinds of compound. ... General formula of a carboxylate ester. ...

Carbodiimides can also react with amines to form guanidines. Ammonia Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ... Guanidine is a crystalline compound of strong alkalinity formed by the oxidation of guanine. ...

Amide formation mechanism

The formation of an amide using a carbodiimide is straightforward, but with several side reactions complicating the subject. The acid 1 will react with the carbodiimide to produce the key intermediate: the O-acylisourea 2, which can be viewed as a carboxylic ester with an activated leaving group. The O-acylisourea will react with amines to give the desired amide 3 and urea 4. General formula of a carboxylate ester. ...

The side reaction of the O-acylisourea 2 produce both desired and undesired products. The O-acylisourea 2 can react with an addition carboxylic acid 1 to give a carboxylic anhydride 5, which can react further to give the desired amide 2. The main undesired reaction pathway involves the rearrangement of the O-acylisourea 2 to the stable N-acylurea 6. The use of solvents with low-dielectric constants such as dichloromethane or chloroform can minimize this side reaction. Acid anhydrides have the general formula (RCO)2O, and appear to be the dehydration product of two carboxylic acid molecules. ... Dichloromethane or Methylene chloride is a chemical compound widely used as a solvent for organic materials. ... PEL-TWA (OSHA) 50 ppm (240 mg/m3) IDLH (NIOSH) 500 ppm Flash point non-flammable RTECS number FS9100000 Supplementary data page Structure & properties n, εr, etc. ...

DCC

DCC
Chemical name	N,N'-dicyclohexylcarbodiimide
Chemical formula	C13H22N2
Molecular mass	206.33 g/mol
Melting point	30-34 °C (dec.)
CAS number	538-75-0
SMILES	C2(CCCCC2)N=C=N C1CCCCC1
Disclaimer and references

DCC (acronym for N,N'-dicyclohexylcarbodiimide) was one of the first carbodiimides developed. It is widely used for amide and ester formation, especially for solid-phase peptide synthesis. DCC has achieved popularity mainly because of its high yielding amide coupling reactions and the fact that it is quite inexpensive. IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... The molecular mass (abbreviated MM) of a substance, called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Dicyclohexylcarbodiimide (DCC) is an organic compound primarily used to couple amino acids during artificial protein synthesis. ... In chemistry, solid-phase synthesis is a method in which molecules are bound on a bead and synthesized step-by-step in a reactant solution; compared with normal synthesis in a liquid state, it is easier to remove excess reactant or byproduct from the product. ... Peptides (from the Greek πεπτος, digestible), are the family of short molecules formed from the linking, in a defined order, of various α-amino acids. ...

However, DCC does have some serious drawbacks, and its use is often avoided unless necessary, for several reasons:

1. The byproduct N,N'-dicyclohexylurea is mostly removed by filtration, but trace amounts remain and are often difficult to remove.
2. DCC is incompatible with traditional solid-phase peptide synthesis. The formed N,N'-dicyclohexylurea is mostly insoluble and is difficult to separate from the peptide resin.
3. Most importantly, DCC is a potent allergen, thus contact with skin can lead to a potentially dangerous allergic reaction.

It has been suggested that solid phase peptide synthesis be merged into this article or section. ... Peptides (from the Greek πεπτος, digestible), are the family of short molecules formed from the linking, in a defined order, of various α-amino acids. ... Insect trapped in resin. ... An allergen is any substance (antigen), most often eaten or inhaled, that is recognized by the immune system and causes an allergic reaction. ...

External links

• DCC Material Safety Data Sheet
• Organic Syntheses, Coll. Vol. 7, p.93; Vol. 63, p.183
• PubChem summary of DCC

DIC

DIC
Chemical name	N,N'-diisopropylcarbodiimide
Chemical formula	C7H14N2
Molecular mass	126.20 g/mol
Boiling point	145-148 °C
Density	0.806 g/cm3
CAS number	693-13-0
SMILES	CC(C)N=C=NC(C)C
Disclaimer and references

DIC (acronym for N,N'-diisopropylcarbodiimide) was developed as an alternative to DCC. DIC is identical to DCC in nearly every way except: IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... The molecular mass (abbreviated MM) of a substance, called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ...

1. As a liquid, DIC is easier to handle than DCC (which is a waxy solid).
2. The product, N,N'-diisopropylurea, is soluble in organic solvents and is easily removed by extraction. Hence, DIC is more often used in solid-phase synthesis.
3. Most importantly, DIC will not induce an allergic reaction.

In chemistry, liquid-liquid extraction is a useful method to separate components (compounds) of a mixture. ... In chemistry, solid-phase synthesis is a method in which molecules are bound on a bead and synthesized step-by-step in a reactant solution; compared with normal synthesis in a liquid state, it is easier to remove excess reactant or byproduct from the product. ...

References

• Tetrahedron Lett. 1994, 35, 5981.
• Int. J. Pept. Protein Res. 1994, 43, 184.

External links

• DIC Material Safety Data Sheet (PDF)
• PubChem summary of DIC

PDF is an abbreviation with several meanings: Portable Document Format Post-doctoral fellowship Probability density function There also is an electronic design automation company named PDF Solutions. ...

EDC

EDC
Chemical name	1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride
Chemical formula	C8H17N3 * HCl
Molecular mass	191.70 g/mol
Melting point	110-114 °C
CAS number	25952-53-8
SMILES	CCN=C=NCCCN(C)C
Disclaimer and references

EDC (acronym for 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride) is a water soluble carbodiimide which is typically employed in the 4.0-6.0 pH range. It is generally used as a carboxyl activating agent for the coupling of primary amines to yield amide bonds. Additionally, EDC can also be used to activate phosphate groups. Commons uses for this carbodiimide include peptide synthesis, protein crosslinking to nucleic acids and preparation of immunoconjugates. IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... The molecular mass (abbreviated MM) of a substance, called molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... The correct title of this article is pH. The initial letter is capitalized because of technical restrictions. ... In inorganic chemistry, a phosphate is a salt of phosphoric acid. ... Schematic diagram of a double-stranded nucleic acid. ...

References

• Nakajima, N; Ikada, Y; Bioconjug Chem. 1995, 6(1), 123-130. Abstract

External links

• PubChem summary of EDC