Me3Si2NH

Me3Si2NH, commonly known as hexamethyldisilazane (HMDS), is an organosilicon compound with the formula C6H19NSi2. It consists of two trimethylsilyl groups bonded to a central NH and is a colorless, volatile liquid at room temperature. HMDS is highly reactive with moisture, hydrolyzing readily to ammonia and hexamethyldisiloxane (Me3Si–O–SiMe3).

HMDS is primarily used as a silylating agent in organic synthesis. It transfers the trimethylsilyl (TMS) group to oxygen and nitrogen nucleophiles, converting alcohols to trimethylsilyl ethers and amines to their trimethylsilyl derivatives. This protection strategy enables moisture-sensitive reactions to be carried out under anhydrous conditions and can simplify purification by temporary masking of reactive functionality. HMDS is also employed as a source of the SiMe3 group in dehydration and related transformations.

In terms of preparation, HMDS is typically manufactured commercially and can be produced by ammonolysis of chlorosilanes or other silane derivatives, with routes in organosilicon chemistry that avoid introducing water into the process.

Handling and safety: HMDS is moisture sensitive and should be stored in tightly closed containers under dry, inert conditions. It can cause irritation to skin, eyes, and the respiratory tract. It hydrolyzes upon contact with water, releasing ammonia and hexamethyldisiloxane. Work with HMDS in a well-ventilated fume hood, wearing appropriate protective equipment, and keep it away from moisture and incompatible materials.