Bis(trimethylsilyl)acetamide

Bis(trimethylsilyl)acetamide

Names
Preferred IUPAC name N-Trimethylsilyl-1-trimethylsilyloxyethanimine
Systematic IUPAC name Trimethylsilyl N-(trimethylsilyl)ethanecarboximidate
Other names N,O-Bis(trimethylsilyl)acetamide
Identifiers
CAS Number	10416-59-8 (E), chlorotimethylsilane 101660-04-2
3D model (Jmol)	Interactive image Interactive image
Abbreviations	BSA
Beilstein Reference	1306669
ChemSpider	23581 4523073 (E) 10516629 (Z)
ECHA InfoCard	100.030.799
EC Number	233-892-7
MeSH	N,O-bis(trimethylsilyl)acetamide
PubChem	25248 6913588 (E) 5372922 (Z)
RTECS number	AK3000000
UNII	R14N49I64O
UN number	2920
InChI InChI=1S/C8H21NOSi2/c1-8(9-11(2,3)4)10-12(5,6)7/h1-7H3 Key: SIOVKLKJSOKLIF-UHFFFAOYSA-N InChI=1/C8H21NOSi2/c1-8(9-11(2,3)4)10-12(5,6)7/h1-7H3/b9-8+
SMILES CC(=N[Si](C)(C)C)O[Si](C)(C)C CC(O[Si](C)(C)C)=N[Si](C)(C)C
Properties
Chemical formula	C8H21NOSi2
Molar mass	203.43 g·mol^−1
Appearance	Liquid
Density	0.832 g cm^−3
Boiling point	71 to 73 °C (160 to 163 °F; 344 to 346 K) at 35mmHg
Hazards
EU classification (DSD)	Corrosive (C)
R-phrases	R10 R14 R22 R34
S-phrases	S26 S36/37/39 S45
Related compounds
Related Amides	Dimethylacetamide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Bis(trimethylsilyl)acetamide (BSA) is an organosilicon compound with the formula Me₃SiNC(OSiMe₃)Me (Me = CH₃). It is a colorless liquid that is soluble in diverse organic solvents, but reacts rapidly with compounds, including solvents and moisture, containing OH and NH functional groups. It is used in analytical chemistry for the derivatisation of compounds in analysis to increase their volatility, e.g. for gas chromatography.^[1] It is also used to introduce the trimethylsilyl protecting group in organic synthesis.^[2] A related reagent is N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA).

Synthesis and reactions

BSA is prepared by treating acetamide with trimethylsilyl chloride in the presence of a base:^[2]

2 Me₃SiCl + H₂NC(O)Me + 2 Et₃N → Me₃SiNC(OSiMe₃)Me + 2 Et₃NHCl

The reaction of BSA with alcohols gives the corresponding trimethylsilyl ether, together with N-(trimethylsilyl)acetamide as a byproduct:

ROH + Me₃SiNC(OSiMe₃)Me → Me₃SiN(H)C(O)Me + ROSiMe₃

References

1. Blau, Karl; J. M. Halket (1993). Handbook of Derivatives for Chromatography (2nd ed.). John Wiley & Sons. ISBN 0-471-92699-X.
2. Harry Heaney, Jian Cui, “N,O-Bis(trimethylsilyl)acetamide” Encyclopedia of Reagents for Organic Synthesis Copyright © 2007 John Wiley & Sons. doi:10.1002/047084289X.rb208.pub2.