A versatile player in the silane world In-depth analysis of chloromethyldimethylsilyl chloride (HC-CM2123) and its application prospects

Chloromethyldimethylchlorosilane

Chemical formula: ClCH₂Si(CH₃)₂Cl

CAS No.: 1719-57-9

Ⅰ. Chemical properties

1.Physical properties

2.Chemical properties

High reactivity:

The molecule contains two chlorine atoms (Cl⁻) and one chloromethyl group (ClCH₂⁻), and is easily hydrolyzed, alcoholyzed, or aminolyzed with nucleophiles (such as water, alcohols, and amines).

Hydrolysis reaction (example):

CICH₂Si(CH₃)₂C1 + 2H₂O → HOCH₂Si(CH₃)₂OH + 2HCI

Electrophilicity: Chloromethyl (ClCH₂⁻) can be used as an alkylating agent and participate in electrophilic substitution reactions in organic synthesis.

Thermal stability: Stable at room temperature, but may decompose at high temperature (＞200℃) and release HCl gas.

Ⅱ. Synthesis Method

1. Laboratory synthesis

Raw materials: methyldichlorosilane ((CH₃)₂SiCl₂) and chloromethylating agent (such as methyl chloride, chloromethyl lithium).

Reaction Path:

step:

In tetrahydrofuran (THF), slowly add chloromethyl Grignard reagent (ClCH₂MgBr) dropwise at low temperature (-10°C).

After the reaction is completed, the product is hydrolyzed and distilled to purify it with a yield of about 60–70%.

2. Industrial preparation

Direct chloromethylation method:

Using methyldichlorosilane as raw material, in the presence of a catalyst (such as AlCl₃), it reacts with methyl chloride (CH₃Cl):

Process characteristics:

Reaction temperature: 80–100°C, pressure: normal pressure;

The catalyst can be recycled and the product can be purified by distillation (purity > 98%).

Ⅲ. Application fields

1. Organic silicon chemical intermediates

Silane coupling agent precursor:

Chloromethyl-containing siloxanes are prepared by hydrolysis or alcoholysis and are used for surface modification of glass fibers and fillers.

Example: Synthesis of chloropropyltrimethoxysilane ( ClCH₂CH₂CH₂Si(OCH₃)₃ ) to enhance the adhesion between rubber and metal.

2. Polymer material modification

Silicone rubber crosslinker:

As a bifunctional crosslinking agent, it participates in the vulcanization reaction of addition-type silicone rubber to improve heat resistance (＞250℃) and mechanical strength.

Case: Used for high temperature seals (automotive engines, aerospace) .

3. Electronic materials

Semiconductor packaging materials:

A silicon-containing resin with low dielectric constant (k < 3.0) is prepared by hydrolysis condensation and used for interlayer dielectric (ILD) of chip packaging.

Photoresist additives:

Improve the adhesion and etching resistance of photoresist (applied in advanced processes below 7nm).

4. Pharmaceutical and pesticide synthesis

Silylation of drug molecules:

As a protecting group reagent, it is used for silylation protection of hydroxyl or amino groups (such as in the synthesis of antibiotic intermediates).

Pesticide synergist:

Modify the molecular structure of pesticides to enhance leaf permeability (such as pyrethroid pesticides).

Surface functionalizing agent:

Used for surface grafting of silicon dioxide and carbon nanotubes to improve their dispersibility in polymer matrices.

Example: Preparation of hydrophobic nano-SiO₂ (contact angle > 150°) for super-hydrophobic coating.

Ⅳ. Safety and operating regulations

1. Danger

Corrosive: It reacts with water to release HCl, which is highly irritating to the skin and eyes;

Flammability: low flash point, keep away from fire;

Environmental toxicity: Toxic to aquatic life, leakage into water bodies must be prevented.

2. Protective measures

Operation protection: Wear chemical-resistant gloves (nitrile/fluororubber), goggles and gas mask;

Storage conditions: Store in sealed containers in a dry, cool place (temperature < 30°C), away from oxidants and alkalis.

3. Emergency treatment

Leakage disposal: Use sand to absorb and collect in special containers, do not flush directly into the sewer;

Fire extinguishing method: Use dry powder or carbon dioxide fire extinguisher. Do not use direct water (to prevent splashing reaction).

Ⅴ. Future Trends

Green synthesis: Develop solvent-free catalytic processes (such as supercritical CO₂ media) to reduce the discharge of three wastes;

Functional expansion: design fluorine/amino-containing derivatives for use in biocompatible materials (such as medical catheter coatings);

High value-added applications: exploration of innovative applications in quantum dot displays and solid-state battery electrolytes.

VI. Summary and Outlook:

As an important organosilicon intermediate, chloromethyldimethylchlorosilane has unique reactivity and broad application prospects. By continuously developing new synthesis methods and application technologies and overcoming existing challenges, it will play a greater role in the field of organosilicon chemistry and contribute to the scientific and technological progress of mankind.

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