Trimethylsilyl azide

Trimethylsilyl azide is the organosilicon compound with the formula (CH₃)₃SiN₃. A colorless liquid, it is a reagent in organic chemistry, serving as the equivalent of hydrazoic acid.^[3]

Trimethylsilyl azide

Names
Preferred IUPAC name Azidotri(methyl)silane
Identifiers
CAS Number	4648-54-8 Y
3D model (JSmol)	Interactive image
Beilstein Reference	1903730
ChemSpider	70747 Y
ECHA InfoCard	100.022.798
EC Number	225-078-5
PubChem CID	78378
CompTox Dashboard (EPA)	DTXSID3063542
InChI InChI=1S/C3H9N3Si/c1-7(2,3)6-5-4/h1-3H3 Y Key: SEDZOYHHAIAQIW-UHFFFAOYSA-N Y InChI=1/C3H9N3Si/c1-7(2,3)6-5-4/h1-3H3 Key: SEDZOYHHAIAQIW-UHFFFAOYAJ
SMILES [N-]=[N+]=N[Si](C)(C)C
Properties
Chemical formula	C3H9N3Si
Molar mass	115.211 g·mol−1
Appearance	colorless liquid
Odor	Odourless;[1] pungent[2]
Density	0.8763 g/cm3 (20 °C)
Melting point	−95 °C (−139 °F; 178 K)
Boiling point	52 to 53 °C (126 to 127 °F; 325 to 326 K) at 175 mmHg (92 to 95 °C at 760 mmHg)
Solubility in water	reacts to form dangerous hydrazoic acid
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H225, H301, H311, H331, H410
Precautionary statements	P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P273, P280, P301+P310, P302+P352, P303+P361+P353, P304+P340, P311, P312, P321, P322, P330, P361, P363, P370+P378, P391, P403+P233, P403+P235, P405, P501
NFPA 704 (fire diamond)	4 3 0
Flash point	6 °C (43 °F; 279 K)
Autoignition temperature	> 300 °C (572 °F; 573 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	100 mg/kg (Oral, expert judgement) 315.8 mg/kg (dermal)[2]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Preparation

Trimethylsilyl azide is commercially available. It may be prepared by the reaction of trimethylsilyl chloride and sodium azide:^[4]

(CH₃)₃Si−Cl + NaN₃ → (CH₃)₃Si−N₃ + NaCl

Reactions

The compound hydrolyzes to hydrazoic acid:^[5]

(CH₃)₃SiN₃ + H₂O → (CH₃)₃SiOH + HN₃

The compound adds to ketones and aldehydes to give the siloxy azides and subsequently tetrazoles:^[3]

(CH₃)₃SiN₃ + R₂CO → R₂C(N₃)OSi(CH₃)₃

It ring-opens epoxides to give azido alcohols.

It has been used in the Oseltamivir total synthesis.

Safety

Trimethylsilyl azide is incompatible with moisture, strong oxidizing agents, and strong acids. Azides are often explosive, as illustrated by their use in air bags.