Phenyl azide
Encyclopedia
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°.
of phenylhydrazine
with nitrous acid
:
, 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.
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." The pure substance may be stored in the dark, cold, and even then the shelf-life is only weeks.
Azide
Azide is the anion with the formula N3−. It is the conjugate base of hydrazoic acid. N3− is a linear anion that is isoelectronic with CO2 and N2O. Per valence bond theory, azide can be described by several resonance structures, an important one being N−=N+=N−...
substituent bound to a phenyl group. The C-N=N angle is approximately 120°.
Preparation
Phenyl azide is prepared by the diazotizationDiazonium compound
Diazonium compounds or diazonium salts are a group of organic compounds sharing a common functional group R-N2+ X- where R can be any organic residue such alkyl or aryl and X is an inorganic or organic anion such as a halogen...
of phenylhydrazine
Phenylhydrazine
Phenylhydrazine is the chemical compound with the formula C6H5NHNH2. Organic chemists abbreviate the compound as PhNHNH2.- Chemical properties :...
with nitrous acid
Nitrous acid
Nitrous acid is a weak and monobasic acid known only in solution and in the form of nitrite salts.Nitrous acid is used to make diazides from amines; this occurs by nucleophilic attack of the amine onto the nitrite, reprotonation by the surrounding solvent, and double-elimination of water...
:
- C6H5NHNH2 + HNO2 → C6H5N3 + 2 H2O
Chemical reactions
C6H5N3 is used to make heterocycles via cycloaddition to alkenes and especially alkynesAzide alkyne Huisgen cycloaddition
The Azide-Alkyne Huisgen Cycloaddition is a 1,3-dipolar cycloaddition between an azide and a terminal or internal alkyne to give a 1,2,3-triazole. Rolf Huisgen was the first to understand the scope of this organic reaction. American chemist K...
, particularly those bearing electronegative substituents. It reacts with triphenylphosphine
Triphenylphosphine
Triphenylphosphine is a common organophosphorus compound with the formula P3 - often abbreviated to PPh3 or Ph3P. It is widely used in the synthesis of organic and organometallic compounds. PPh3 exists as relatively air stable, colorless crystals at room temperature...
to give the Staudinger reagent C6H5NP(C6H5)3. Thermolysis induces loss of N2 to give the highly reactive phenylnitrene C6H5N.
Safety
Because of the potential for explosion, a protective blast shield is recommended during purification and handling. Distillation temperatures should be as low a possible. Organic SynthesesOrganic Syntheses
Organic Syntheses is a scientific journal that since 1921 has provided the chemistry community with annual collections of detailed and checked procedures for the organic synthesis of organic compounds. The journal is peer reviewed...
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." The pure substance may be stored in the dark, cold, and even then the shelf-life is only weeks.