Diphenylphosphoryl azide

"DPPA" redirects here. For the Driver's Privacy Protection Act, see Driver's Privacy Protection Act.

Diphenylphosphoryl azide
IUPAC name Diphenyl phosphorazidate
Other names Diphenylphosphonic azide Diphenyl azidophosphate Phosphoric acid diphenyl ester azide
Identifiers
Abbreviations	DPPA
CAS number	26386-88-9 Y
PubChem	199401
ChemSpider	172597 Y
Jmol-3D images	Image 1
SMILES O=P(N=[N+]=[N-])(c1ccccc1)c2ccccc2
InChI InChI=1S/C12H10N3OP/c13-14-15-17(16,11-7-3-1-4-8-11)12-9-5-2-6-10-12/h1-10H Y Key: MKRTXPORKIRPDG-UHFFFAOYSA-N Y InChI=1/C12H10N3OP/c13-14-15-17(16,11-7-3-1-4-8-11)12-9-5-2-6-10-12/h1-10H Key: MKRTXPORKIRPDG-UHFFFAOYAD
Properties
Molecular formula	C12H10N3O3P
Molar mass	275.20 g/mol
Appearance	Colourless or faintly yellow liquid
Density	1.277 g/cm3
Boiling point	157 °C (0.2 mmHg)
Hazards
EU classification	Toxic (C)
NFPA 704	1 4 0
Flash point	112 °C
Y (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

Diphenylphosphoryl azide (DPPA; IUPAC name: Diphenyl phosphorazidate) is an organic compound. It is widely used in synthesis of other organic compounds.^[1]

Synthesis

Diphenylphosphoryl azide has been obtained by reaction of the phosphorochloridate with sodium azide. The stability of the azide towards heating was shown by its distillation at 157 °C and by the fact that vigorous evolution of nitrogen was not observed until a temperature of 175 °C had been reached.^{[citation needed]}

Uses

This compound undergoes pseudohalogen replacement of the azido group by treatment with nucleophilic reagents, such as water, butanol, ammonia, and various amines.

This compound is used as a reagent for the synthesis of peptides by virtue of its reactions with carboxylic acids leading to either the urethane or the amide. The formation of the urethane is particularly valuable since it works with carboxylic acids which fail to undergo the Schmidt reaction, and is believed to involve transfer of the azido group to the carboxylic acid.

It is now suggested that this reaction proceeds through the intermediate mixed anhydride, resulting from attack by the nucleophilic carboxylate anion on the phosphorus atom, with expulsion of the azide ion. The latter then attacks the carbonyl carbon atom, to give the acyl azide and loss of the diphenyl phosphate anion, known to be a good leaving group. Finally, the acyl azide reacts in the normal manner to give the urethane.

The present studies show that diphenylphosphoryl azide reacts with amines giving the corresponding phosphoramidates; it therefore appears that formation of the amide similarly involves the intermediate anhydride, followed by nucleophilic substitution by the amine.

References

1. ^ Some Reactions of O,O-Diphenylphosporyl Azide, Australian Journal of Chemistry, 1973, 26, 1591-3.