Used primarily as an intermediate in organic synthesis, particularly in the preparation of pharmaceuticals and agrochemicals. It serves as a building block in the formation of heterocyclic compounds due to its reactive nitroso group. Commonly employed in the development of nitrogen-containing bioactive molecules, including certain antiviral and anticancer agents. Also utilized in research settings for the modification of peptides and proteins through selective labeling. Its ability to act as a nitrosating agent makes it valuable in controlled nitrosation reactions, though handling requires caution due to potential instability and toxicity.