1-Fluoro-2,4-dinitrobenzene

1-Fluoro-2,4-dinitrobenzene
IUPAC name 1-fluoro-2,4-dinitrobenzene
Other names Dinitrofluorobenzene
Identifiers
Abbreviations	DNFB
CAS number	70-34-8 Y
PubChem	6264
ChemSpider	21106037 Y
UNII	D241E059U6 Y
ChEBI	CHEBI:53049 N
ChEMBL	CHEMBL167423 N
Jmol-3D images	Image 1
SMILES O=[N+]([O-])c1cc(ccc1F)[N+]([O-])=O
InChI InChI=1S/C6H3FN2O4/c7-5-2-1-4(8(10)11)3-6(5)9(12)13/h1-3H N Key: LOTKRQAVGJMPNV-UHFFFAOYSA-N N InChI=1/C6H3FN2O4/c7-5-2-1-4(8(10)11)3-6(5)9(12)13/h1-3H Key: LOTKRQAVGJMPNV-UHFFFAOYAZ
Properties
Molecular formula	C6H3FN2O4
Molar mass	186.1 g mol−1
Appearance	yellow crystals[1]
Density	1.4718 g·cm−3 (54 °C)[2]
Melting point	25.8 °C[2]
Boiling point	296 °C[2]
Hazards
MSDS	[1]
EU classification	T
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

1-fluoro-2,4-dinitrobenzene, or Sanger's reagent (commonly called dinitrofluorobenzene or DNFB), is a chemical used for polypeptide sequencing.

Preparation

In 1936, Gottlieb presented a synthesis in which 1-chloro-2,4-dinitrobenzene reacted with potassium fluoride (KF) in nitrobenzene:^[3]

Uses

Frederick Sanger

In 1945, Frederick Sanger described its use for determining the N-terminal amino acid in polypeptide chains, in particular insulin.^[4] Sanger's initial results suggested that insulin was a smaller molecule than previously estimated (molecular weight 12,000), and that it consisted of four chains (two ending in glycine and two ending in phenylalanine), with the chains cross-linked by disulfide bonds. Sanger continued work on insulin, using dinitrofluorobenzene in combination with other techniques, eventually resulted in the complete sequence of insulin (consisting of only two chains, with a molecular weight of 6,000).^[5]

Following Sanger's initial report of the reagent, the dinitrofluorobenzene method was widely adopted for studying proteins, until it was superseded by other reagents for terminal analysis (e.g., dansyl chloride and later aminopeptidases and carboxypeptidases) and other general methods for sequence determination (e.g., Edman degradation).^[5]

Dinitrofluorobenzene reacts with the amine group in amino acids to produce dinitrophenyl-amino acids. These DNP-amino acids are moderately stable under acid hydrolysis conditions that break peptide bonds. The DNP-amino acids can then be recovered, and the identity of those amino acids can be discovered through chromatography.

Sanger's method of peptide end-group analysis: A derivatization of N-terminal end with Sanger's reagent (DNFB), B total acid hydrolysis of the dinitrophenyl peptide

See also

• Use of Fedric Reagent in protein sequencing

References

1. ^ ^{a b} Oxford MSDS
2. ^ ^{a b c} CRC Handbook of Chemistry and Physics, 90. edition, CRC Press, Boca Raton, Florida, 2009, ISBN 978-1-4200-9084-0, Section 3, Physical Constants of Organic Compounds, p. 3-260.
3. ^ Hans Billroth Gottlieb: "The Replacement of Chlorine by Fluorine in Organic Compounds", J. Am. Chem. Soc., 1936, 58 (3), S. 532–533; doi:10.1021/ja01294a502.
4. ^ Sanger, F (1945). "The free amino groups of insulin". The Biochemical journal 39 (5): 507–15. PMC 1258275. PMID 16747948. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1258275. 
5. ^ ^{a b} Joseph Fruton, Proteins, Enzymes, Genes: The Interplay of Chemistry and Biology. New Haven: Yale University Press, 1999. p. 216.

Literature

• T. Schaefer: "The Proton Magnetic Resonance Spectrum of 1-Fluoro-2,4-dinitrobenzene", Canadian Journal of Chemistry, 1961, 40, pp. 431–433; doi:10.1139/v62-068.
• B. D. Nageswara Rao: "The ¹H and ¹⁹F Resonance Spectra of 1-Fluoro-2,4-dinitrobenzene", Molecular Physics, 1964, 7 (4), pp. 307–310; doi:10.1080/00268976300101071.
• A. Wilkins, R. W. H. Small: "Structure of 1-Fluoro-2,4-dinitrobenzene", Acta Cryst., 1991, C47, pp. 220–221; doi:10.1107/S0108270190007326.

External links

• Fluorodinitrobenzene – 1-fluoro-2,4-dinitro-benzene (wikigenes.org)