Used primarily as a reagent in organic synthesis for methylation reactions, often generating diazomethane in situ. It is particularly employed in the preparation of heterocyclic compounds and serves as a source of methyl and nitroso groups in the synthesis of pharmaceuticals and agrochemicals. This compound plays a key role in developing biologically active molecules, such as antimicrobials and anticancer agents. Handle with care, as nitrosothioureas may exhibit mutagenic or carcinogenic properties and require controlled laboratory conditions due to toxicity and instability.