Diphenylphosphoryl azide

Diphenylphosphoryl azide

Names
IUPAC name Diphenyl phosphorazidate
Other names Diphenoxyphosphoryl azide Diphenylphosphonic azide Diphenyl azidophosphate Phosphoric acid diphenyl ester azide
Identifiers
CAS Number	26386-88-9 Y
3D model (JSmol)	Interactive image
Abbreviations	DPPA
ChemSpider	172597 Y
ECHA InfoCard	100.043.298
PubChem CID	123414
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
SMILES O=P(N=[N+]=[N-])(c1ccccc1)c2ccccc2
Properties
Chemical formula	C12H10N3O3P
Molar mass	275.20 g·mol−1
Appearance	Colourless or faintly yellow liquid
Density	1.277 g/cm3
Boiling point	157 °C (315 °F; 430 K) (0.2 mmHg)
Hazards
EU classification (DSD) (outdated)	Toxic (T)
NFPA 704	1 4 0
Flash point	112 °C (234 °F; 385 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Diphenylphosphoryl azide (DPPA; alternative, more precise name: diphenoxyphosphoryl azide; IUPAC name: diphenyl phosphorazidate) is an organic compound. It is widely used in synthesis of other organic compounds.

DPPA 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 diphenylphosphate anion, known to be a good leaving group. Finally, the acyl azide reacts in the normal manner to give the urethane.

Studies show that DPPA 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.