Hexamethyldisilazane, also known as HMDS, is an important organosilicon compound, a colorless and transparent liquid. It is readily hydrolyzed and gives off NH3 to produce hexamethyldisilyl ether. In the presence of a catalyst, it reacts with alcohols or phenols to produce trimethylalkoxysilane or trimethylaroxysilane. Reacts with anhydrous hydrogen chloride, releasing NH3 or NH4Cl, to produce trimethylchlorosilane.