N-Boc-N'-methylthiourea is a Boc-protected thiourea derivative used as a versatile intermediate in organic synthesis. The tert-butoxycarbonyl (Boc) group protects one of the nitrogen atoms, allowing for selective reactions on the methyl-substituted nitrogen and easy deprotection under mild acidic conditions. It is particularly valuable in peptide chemistry and medicinal chemistry for constructing complex molecules, including heterocycles like thiazoles and guanidine derivatives. This compound helps prevent unwanted side reactions and serves as a building block in the development of pharmaceuticals and bioactive compounds.