Chlorotrimethylsilane CAS 75-77-4

What Chlorotrimethylsilane Is

Chlorotrimethylsilane is the simplest chlorotrimethylsilane, a small organosilicon molecule in which three methyl groups and one chlorine sit on a silicon atom. It is a clear, colorless, highly volatile liquid that fumes in moist air and boils at 57 °C. The chlorine is easily replaced, so the molecule transfers a trimethylsilyl group to active hydrogen sites, and this single reaction drives most of the demand. Industrial grade moves in steel drums and ISO tanks to silicone producers, while high-purity, low-moisture lots in smaller packing serve pharmaceutical protecting-group steps and GC derivatization, with the assay reported on each COA. UATChem supplies both forms.

Where It Is Used

• Silyl protection in drug synthesis. It caps alcohols, carboxylic acids, amines and heterocyclic nitrogen with a trimethylsilyl group during multistep API routes, including cephalosporin and antiviral syntheses, and the group is removed again when the step is over.
• GC and GC-MS derivatization. High-purity lots convert polar hydroxyl, carboxyl and amine samples into volatile trimethylsilyl derivatives for cleaner chromatography, often together with HMDS or BSTFA.
• Silicone end-capping and intermediates. It terminates chains in silicone oil, resin and rubber and is the main raw material for hexamethyldisiloxane and hexamethyldisilazane.
• General organic synthesis. It serves as an activating and dehydrating reagent and a route to silyl enol ethers, and it also gives glass, fabric and electronic surfaces a water-repellent finish.

Typical Specifications

Industrial and high-purity reagent lots share the same physical identity below, while the GC assay and any impurity limits are reported on the COA for each lot.

Storage, Handling and Ordering

• Keep it in tightly closed, dry steel drums under nitrogen in a cool, ventilated, explosion-proof store below 30 °C, away from water, alcohols, bases, acids and oxidizers. Trace moisture hydrolyzes the liquid and releases hydrochloric acid, so dry transfer lines and nitrogen blanketing matter.
• Wear goggles, gloves and protective clothing under fume extraction, as the liquid burns skin and eyes and the vapors irritate airways. Fight fire with dry powder, carbon dioxide or alcohol-resistant foam, never a water jet.
• UATChem packs 170 kg sealed steel drums and ISO tanks for volume, with sample bottles on request and COA and SDS with every order. The liquid travels as dangerous goods and not on passenger aircraft. Send grade, quantity and destination for a quote.

FAQ

Q: What is chlorotrimethylsilane mainly used for?

A: It protects active hydrogen groups in API synthesis, derivatizes GC samples and end-caps silicone oil, resin and rubber.

Q: Which grade and packing should be ordered?

A: Use industrial grade in 170 kg drums or ISO tanks for silicone work, and high-purity small-pack lots for pharma and GC.

Q: How is it packed and shipped?

A: It ships in sealed 170 kg steel drums or ISO tanks as dangerous goods, with COA and SDS and no passenger air freight.