Hexamethyldisilazane, which is also known as HMDS, is a special organosilicon compound that is a derivative of ammonia. It is different from the traditionally known compound because it has trimethylsilyl groups in place of the two hydrogen atoms. It is a colorless liquid that is a popular reagent and precursor to many bases, making the compound a very popular ingredient in different types of organic synthesis and organometallic chemistry. Among its most common uses are application in photolithography. In this field, HMDS is often used as a special adhesion promoter for the photoresist. Professionals who work in this field will generate the best results by applying HMDS from its gas phase onto heated substrates. In electron microscopy, this compound can also be used as an alternative to traditional critical point drying during stages of sample preparation. Another popular use of HDMS is as a powerful reagent in the condensation reactions of heterocyclic compounds.