4Mercaptopropanoic

4-Mercaptopropanoic acid, also known as 3-mercaptopropanoic acid or $\beta$-thiolpropionic acid, is an organic compound with the chemical formula HS(CH2)2COOH. It is a thiol and a carboxylic acid, possessing both a sulfhydryl group (-SH) and a carboxyl group (-COOH). This bifunctional nature allows it to participate in a variety of chemical reactions.

The compound is typically a colorless liquid or low-melting solid with a characteristic thiol odor. It is soluble in water and many organic solvents. 4-Mercaptopropanoic acid is often used as a chemical intermediate in the synthesis of various organic molecules, including polymers, pharmaceuticals, and agrochemicals. Its thiol group can undergo oxidation to form disulfides, and it can also react with electrophiles. The carboxylic acid group allows for esterification and salt formation. It can be synthesized through several routes, often involving reactions of propanol derivatives with sulfur-containing compounds. Due to its reactive functional groups, it requires careful handling and storage to prevent degradation.