Bromotrimethylsilane Property

Melting point:

-43 °C

Boiling point:

79 °C(lit.)

Density 

1.16 g/mL at 25 °C(lit.)

refractive index 

n20/D 1.424(lit.)

Flash point:

90 °F

storage temp. 

Store below +30°C.

solubility 

DECOMPOSES

form 

Liquid

Specific Gravity

1.1725

color 

Clear colorless to yellow

Water Solubility 

DECOMPOSES

Sensitive 

Moisture Sensitive

Hydrolytic Sensitivity

8: reacts rapidly with moisture, water, protic solvents

BRN 

1731135

Stability:

Stable. Flammable. Incompatible with strong acids, strong oxidizing agents. May decompose on exposure to water or moist air.

CAS DataBase Reference

2857-97-8(CAS DataBase Reference)

NIST Chemistry Reference

Bromotrimethylsilane(2857-97-8)

EPA Substance Registry System

Silane, bromotrimethyl- (2857-97-8)

Safety

Hazard Codes 

C

Risk Statements 

10-34-29-14

Safety Statements 

16-26-36/37/39-45-8

RIDADR 

UN 2920 8/PG 2

WGK Germany 

3

F 

10-21

TSCA 

Yes

HazardClass 

3

PackingGroup 

II

HS Code 

29310095

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H225Highly Flammable liquid and vapour

H314Causes severe skin burns and eye damage

H335May cause respiratory irritation

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P233Keep container tightly closed.

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

Bromotrimethylsilane Chemical Properties,Usage,Production

Uses

Bromotrimethylsilane can protect or deprotect functional groups selectively, act as silane blocking agent, which is widely used in the syntheses of drugs.

Chemical Properties

Clear yellow liquid

Physical properties

bp 79°C; d 1.188 g cm?3; n20 D 1.4240; fp 32°C.

Uses

Powerful silylating agent

Uses

Adefovir intermediate

Uses

Bromotrimethylsilane is a mild and selective reagent for cleavage of lactones, epoxides, acetals, phosphonate esters and certain ethers; effective reagent for formation of silyl enol ethers; can function as brominating agent.
Amines react with TMS-Br to form isolable adducts, which react readily with ketones to form enamines under mild conditions (eq 15).

Preparation

although many methods are reported, only a few are provided here: chlorotrimethylsilane undergoes halogen exchange with either magnesium bromide in Et2O or sodium bromide in MeCN, which allows in situ reagent formation (eq 1); alternatively, hexamethyldisilane reacts with bromine in benzene solution or neat, to afford only TMS-Br with no byproducts (eq 2).4 TMS-Br may also be generated by reaction of hexamethyldisiloxane and aluminum bromide (eq 3).However, it should be noted that the reactivity of in situ generated reagent appears to depend upon the method of preparation.

General Description

Bromotrimethylsilane is used with Cl₃ to catalyze the direct allylation of a variety of alcohols with allyltrimethylsilane.

Purification Methods

Purify it by repeated fractional distillation and store it in sealed ampoules in the dark. [McCusker & Reilly J Am Chem Soc 75 1583 1953.] Also fractionate it through a 15-plate column (0.8 x 32cm packed with 1/16in single turn helices of Pt-Ir wire). [Gilliam et al. J Am Chem Soc 68 1161 1946, Pray et al. J Am Chem Soc 70 433 1948, Beilstein 4 IV 4008.]