Phenyl azide

Phenyl azide

Names
IUPAC name Phenyl azide
Other names Azidobenzene
Identifiers
CAS Number	622-37-7 Y
ChemSpider	62529 N
EC Number	210-730-3
Jmol interactive 3D	Image
MeSH	C014747
PubChem	69319
InChI InChI=1S/C6H5N3/c7-9-8-6-4-2-1-3-5-6/h1-5H N Key: CTRLRINCMYICJO-UHFFFAOYSA-N N InChI=1/C6H5N3/c7-9-8-6-4-2-1-3-5-6/h1-5H Key: CTRLRINCMYICJO-UHFFFAOYAH
SMILES [N-]=[N+]=NC1=CC=CC=C1
Properties
Chemical formula	C6H5N3
Molar mass	119.13 g·mol−1
Appearance	Pale yellow, oily liquid
Boiling point	49 to 50 °C (120 to 122 °F; 322 to 323 K) at 5 mmHg
Solubility in water	not appreciable
Hazards
Main hazards	explosive
Related compounds
Related compounds	Aniline Nitrobenzene Nitrosobenzene Phenylhydrazine Phenylhydroxylamine Diazonium cation
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

Phenylazide is an organic compound with the formula C₆H₅N₃. It is one of the prototypical organic azides. It has a pungent odor. The structure consists of a linear azide substituent bound to a phenyl group. The C-N=N angle is approximately 120°.

Preparation

Phenyl azide is prepared by the diazotization of phenylhydrazine with nitrous acid:^[1]

C₆H₅NHNH₂ + HNO₂ → C₆H₅N₃ + 2 H₂O

Aryl iodides bearing electron-withdrawing substituents undergo metathesis with sodium azide in the presence of Cu(I), sodium ascorbate, and N,N'-dimethylethane-1,2-diamine (DMEA):

RC₆H₄I + NaN₃ → RC₆H₄N₃ + NaI

Chemical reactions

C₆H₅N₃ is used to make heterocycles via cycloaddition to alkenes and especially alkynes, particularly those bearing electronegative substituents. It reacts with triphenylphosphine to give the Staudinger reagent C₆H₅NP(C₆H₅)₃. Thermolysis induces loss of N₂ to give the highly reactive phenylnitrene C₆H₅N.^[2]

Phenyl azide and its analogues undergo the azide alkyne Huisgen cycloaddition, a classic example of click chemistry. For example, phenyl azide and phenylacetylene give diphenyl triazole.

Safety

Because of the potential for explosion,^[1] a protective blast shield is recommended during purification and handling. Distillation temperatures should be as low a possible. Organic Syntheses recommends a vacuum of 5mm Hg to give a boiling point of "66–68 °C/21 mm. with a bath temperature of 70–75 °C."^[1] The pure substance may be stored in the dark, cold, and even then the shelf-life is only weeks.

References