Chlorotrimethylsilane
[CAS# 75-77-4]

Identification

• Classification: Organic raw materials >> Organosilicon compound
• Name: Chlorotrimethylsilane
• Synonyms: Trimethylchlorosilane; Trimethylsilyl chloride; CSI
• Molecular Formula: C₃H₉ClSi
• Molecular Weight: 108.64
• CAS Registry Number: 75-77-4
• EC Number: 200-900-5
• SMILES: C[Si](C)(C)Cl

Properties

• Density: 0.856
• Melting point: -58 °C
• Boiling point: 57 °C
• Refractive index: 1.387-1.389
• Flash point: -18 °C
• Water solubility: REACTS

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS06;GHS07;GHS08 Danger
• Risk Statements: H225-H301-H312-H314-H331-H351
• Safety Statements: P203-P210-P233-P240-P241-P242-P243-P260-P261-P264-P270-P271-P280-P301+P316-P301+P330+P331-P302+P352-P302+P361+P354-P303+P361+P353-P304+P340-P305+P354+P338-P316-P317-P318-P321-P330-P362+P364-P363-P370+P378-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	2	H225
Acute toxicity	Acute Tox.	4	H312
Skin corrosion	Skin Corr.	1A	H314
Acute toxicity	Acute Tox.	3	H301
Carcinogenicity	Carc.	2	H351
Acute toxicity	Acute Tox.	2	H331
Acute toxicity	Acute Tox.	3	H331
Serious eye damage	Eye Dam.	1	H318
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H332
Acute toxicity	Acute Tox.	4	H302
Specific target organ toxicity - single exposure	STOT SE	1	H370
Skin corrosion	Skin Corr.	1C	H314
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Skin corrosion	Skin Corr.	1B	H314
Specific target organ toxicity - single exposure	STOT SE	2	H371
Skin corrosion	Skin Corr.	1	H314
Substances or mixtures corrosive to metals	Met. Corr.	1	H290

• Transport Information: UN 1298

Discovery and Applications

Chlorotrimethylsilane, with the chemical formula (CH₃)₃SiCl, is a versatile organosilicon compound used in a wide variety of chemical synthesis processes. It belongs to the class of organosilanes, which are characterized by a silicon atom bonded to three methyl groups and one chlorine atom.

Chlorotrimethylsilane was first synthesized and characterized in the mid-20th century as part of the expanding field of organosilicon chemistry. Its discovery stemmed from the need for efficient silanizing agents that were able to introduce trimethylsilyl groups (-Si(CH₃)₃) into organic molecules. This ability significantly enhances the stability, volatility, and reactivity of organic compounds, making chlorotrimethylsilane a valuable tool in synthetic chemistry.

The synthesis of chlorotrimethylsilane involves the reaction of trimethylchlorosilane with methyl chloride under controlled conditions. Trimethylchlorosilane (Me₃SiCl) reacts with methyl chloride (CH₃Cl) in the presence of a catalyst, typically a Lewis acid such as aluminum chloride (AlCl₃), to produce chlorotrimethylsilane. The crude product undergoes a purification process to remove impurities and obtain high purity chlorotrimethylsilane suitable for various applications.

Chlorotrimethylsilane is primarily used as a silanizing agent in organic synthesis. It readily reacts with hydroxyl (-OH) groups in organic compounds to form trimethylsilyl ethers (-OSi(CH₃)₃), thereby protecting these groups from undesirable reactions and enhancing the stability of the compound during chemical transformations.

In industrial processes, chlorotrimethylsilane is used as a catalyst or intermediate in the manufacture of silicone polymers and resins. It participates in the synthesis of silicone oils, elastomers, and sealants, and its ability to change the molecular structure through silylation reactions is essential for controlling product properties such as viscosity and elasticity.

The chemical properties of chlorotrimethylsilane make it useful in surface modification technology. It coats surfaces with trimethylsilyl groups, imparting hydrophobic properties and enhancing surface durability and resistance to moisture, corrosion, and microbial growth.

Chlorotrimethylsilane is used in the pharmaceutical and agrochemical industries for the synthesis of active pharmaceutical ingredients (APIs) and agrochemicals. Its role in protecting functional groups and improving compound stability aids in the development of effective pharmaceuticals and crop protection agents.

Chlorotrimethylsilane is a reactive chemical that requires careful handling and storage. It should be used in a well-ventilated area with appropriate personal protective equipment (PPE) to prevent inhalation or skin contact. Safety procedures include handling under inert atmosphere conditions to avoid moisture and air-sensitive reactions.

References

2008. One-pot conversion of trimethylsilyl ethers into urethanes using chlorosulfonyl isocyanate: Application to the synthesis of a novel neuromodulator carisbamate. Archives of Pharmacal Research, 31(11).
DOI: 10.1007/s12272-001-2122-1

2012. New approach for the synthesis of novel acenaphtho[1,2-b]furan-8-amines. Molecular Diversity, 16(1).
DOI: 10.1007/s11030-012-9356-3

2024. Cystine coupled tyrosine modified disposable pencil graphite electrode for the simultaneous analysis of adenine and thymine. Chemical Papers.
DOI: 10.1007/s11696-024-03824-5