Fmoc-OSu Chemical Properties

Melting point:

150-153 °C(lit.)

Boiling point:

150-153°C

Density 

1.3460 (rough estimate)

refractive index 

1.5000 (estimate)

storage temp. 

2-8°C

solubility 

Soluble in dimethyl sulfoxide and dimethyl formamide.

form 

Microfine Powder

color 

White or almost white

Sensitive 

Moisture Sensitive

BRN 

3569540

Stability:

Moisture Sensitive

InChI

InChI=1S/C19H15NO5/c21-17-9-10-18(22)20(17)25-19(23)24-11-16-14-7-3-1-5-12(14)13-6-2-4-8-15(13)16/h1-8,16H,9-11H2

InChIKey

WMSUFWLPZLCIHP-UHFFFAOYSA-N

SMILES

C(OCC1C2=C(C=CC=C2)C2=C1C=CC=C2)(=O)ON1C(=O)CCC1=O

CAS DataBase Reference

82911-69-1(CAS DataBase Reference)

Safety Information

Hazard Codes 

Xi,N,Xn

Risk Statements 

36/37/38-51/53-43-22

Safety Statements 

22-24/25-26/37/39-26-61-37-24

RIDADR 

UN 3077 9 / PGIII

WGK Germany 

3

F 

10-21

Hazard Note 

Moisture Sensitive

HazardClass 

9

HS Code 

29251995

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

Fmoc-OSu Usage And Synthesis

Description

Fmoc-OSu (N-(9-Fluorenylmethoxycarbonyloxy)succinimide) is a reagent used in solid-phase peptide synthesis (SPPS) for Fmoc protection of amino groups, particularly amino acids. This reagent contains an Fmoc functional group, which is stable under acidic conditions and cleaves under alkaline conditions. Fmoc-OSu reacts with amino groups to form stable amide bonds, helping to reduce the occurrence of side reactions. Additionally, Fmoc-OSu can also be used as a fluorescent reagent.

Chemical Properties

White powder

Uses

N-protecting reagent for oligonucleotide and peptide syntheses

Uses

Reagent for the preparation of pure Fmoc amino acids free from contamination by Fmoc-dipeptides.

Uses

N-(9-Fluorenylmethoxycarbonyloxy)succinimide is used in conjunction with Isothiocyanate to conduct partial Edman Degradation on biologically active peptides.

Mechanism of action

The protective mechanism of Fmoc-OSu involves the amine group (R-NH₂) of the protected molecule acting as a nucleophile and attacking the carbonyl carbon of the Fmoc-OSu molecule, forming a tetrahedral intermediate. where the nitrogen of the amine is now bonded to the carbonyl carbon of the Fmoc group, yielding an Fmoc-protected amine and a succinimide. The Fmoc group is typically removed using bases such as piperidine, which can remove the Fmoc group without hydrolyzing the peptide backbone. In solid-phase peptide synthesis (SPPS), the removal of the Fmoc group occurs via a two-step mechanism: first, the acidic proton at the 9-position of the naphthalene ring system is removed using a mild base (preferably a secondary amine), followed by a β-elimination reaction, generating a highly reactive dibenzofuran (DBF) intermediate, which is immediately captured by the secondary amine to form a stable adduct.

Purification Methods

Recrystallise the carbonate from CHCl3/Et2O, or from pet ether (b 40-60o). [Pauet Can J Chem 60 976 1982, Lapatsaris et al. Synthesis 671 1983.]

Fmoc-OSu(82911-69-1)Related Product Information

• Fmoc-Aib-OH
• Bismaleimide
• Tris(trimethylsilyl)phosphate
• Barium carbonate
• Zinc carbonate
• N-Hydroxysuccinimide
• 9-Fluorenylmethyl chloroformate
• Lithium carbonate
• Ethylene carbonate
• Ammonium carbonate
• O-Phthalimide
• Dimethyl carbonate
• Sodium carbonate
• Succinimide
• Calcium carbonate
• DIALIFOS
• N-Methoxy-N-methylacetamide
• 9-Fluorenemethanol