CHLOROTRIBENZYLSILANE Property

Melting point:

139-142 °C(lit.)

Boiling point:

437.9±14.0 °C(Predicted)

Density 

1.096±0.06 g/cm3(Predicted)

solubility 

sparingly sol cold petroleum ether; moderately sol hot petroleum ether; sol ether.

EPA Substance Registry System

Silane, chlorotris(phenylmethyl)- (18740-59-5)

Safety

Hazard Codes 

C

Risk Statements 

34

Safety Statements 

26-36/37/39-45

RIDADR 

UN 3261 8/PG 2

WGK Germany 

3

F 

10-21

HazardClass 

8

PackingGroup 

II

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H314Causes severe skin burns and eye damage

Precautionary statements

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

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

P310Immediately call a POISON CENTER or doctor/physician.

CHLOROTRIBENZYLSILANE Chemical Properties,Usage,Production

Physical properties

mp 141–142 °C;1,2 a somewhat higher value (143–145 °C) is cited in the Aldrich catalog.

Uses

Tribenzylchlorosilane is widely used as reagent for alcohol protection.

Preparation

It is prepared by reaction of benzylmagnesium chloride with SiCl4 in ether; separation from mono- and dibenzylated chlorosilane byproducts is then accomplished by fractional distillation (boiling range 300–360 °C/100 mmHg). Other preparations involve the chlorination of tribenzylsilane using Cl2 or an acyl chloride. No yields are reported for any of the above preparative procedures.

Purification Methods

It is recrystallised three times from pet ether (in slender colourless needles, m 141o). It is sparingly soluble in pet ether but is soluble in Et2O. It does not fume in moist air but is decomposed by H2O to give tribenzyl silanol m 106o (from pet ether). [Robinson & Kipping J Chem Soc 93 439 1908, Jenkins & Post J Org Chem 15 556 1950, Beilstein 16 H 906, 16 IV 1498.]