Bis(trimethylsilyl)acetamide
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).
Names | |
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Preferred IUPAC name
N-Trimethylsilyl-1-trimethylsilyloxyethanimine | |
Systematic IUPAC name
Trimethylsilyl N-(trimethylsilyl)ethanecarboximidate | |
Other names
N,O-Bis(trimethylsilyl)acetamide | |
Identifiers | |
3D model (JSmol) |
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Abbreviations | BSA |
1306669 | |
ChemSpider | |
ECHA InfoCard | 100.030.799 |
EC Number |
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MeSH | N,O-bis(trimethylsilyl)acetamide |
PubChem CID |
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RTECS number |
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UNII | |
UN number | 2920 |
CompTox Dashboard (EPA) |
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Properties | |
C8H21NOSi2 | |
Molar mass | 203.432 g·mol−1 |
Appearance | Liquid |
Density | 0.832 g cm−3 |
Melting point | 24 °C (75 °F; 297 K) |
Boiling point | 71 to 73 °C (160 to 163 °F; 344 to 346 K) at 35mmHg |
Hazards | |
GHS pictograms | |
GHS Signal word | Danger |
H226, H302, H314 | |
P210, P233, P240, P241, P242, P243, P260, P264, P270, P280, P301+312, P301+330+331, P303+361+353, P304+340, P305+351+338, P310, P321, P330, P363, P370+378, P403+235, P405, P501 | |
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 | |
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
- Blau, Karl; J. M. Halket (1993). Handbook of Derivatives for Chromatography (2nd ed.). John Wiley & Sons. ISBN 0-471-92699-X.
- 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.