Bis(trimethylsilyl)amine
Bis(trimethylsilyl)amine, often abbreviated as BSA or HMDS (Hexamethyldisilazane) after its synthesis precursor, is an organosilicon compound with the formula (Me3Si)2NH, where Me represents the methyl group (CH3). It is a colorless liquid with a strong ammonia-like odor, and it is soluble in common organic solvents.
Bis(trimethylsilyl)amine is primarily used as a silylating agent, introducing trimethylsilyl (TMS) groups into molecules. This process is often used to protect reactive functional groups, such as alcohols, amines, and carboxylic acids, making them less reactive or more volatile for analysis, such as in gas chromatography-mass spectrometry (GC-MS). The silylation reaction typically involves the replacement of an active hydrogen atom in the target molecule with a trimethylsilyl group.
The reaction with bis(trimethylsilyl)amine produces ammonia as a byproduct. This byproduct can sometimes interfere with subsequent reactions or analyses, and its presence should be considered. Various protocols exist to minimize its effects, such as using excess silylating agent or adding a base to neutralize the ammonia.
Beyond its use as a silylating reagent, bis(trimethylsilyl)amine is also utilized in the synthesis of other organosilicon compounds and in the preparation of metal amides. It can act as a base, deprotonating acidic compounds.
Handling bis(trimethylsilyl)amine requires care due to its flammability and sensitivity to moisture. It should be stored under anhydrous conditions and handled in a well-ventilated area. The compound can react with water to form hexamethyldisiloxane and ammonia.