(S)-3-(3,4-Dimethoxyphenyl)-2-methyl-2-ureidopropanoic acid is a chiral amino acid derivative featuring a ureido group and a 3,4-dimethoxyphenyl substituent. Its molecular formula is C13H18N2O5, and it is characterized by the (S)-configuration at the stereogenic center, which is crucial for its biological activity. This compound is a key chiral intermediate in the synthesis of Droxidopa (also known as L-DOPS or Northera®). Droxidopa is a synthetic amino acid precursor that is converted to norepinephrine by the enzyme aromatic L-amino acid decarboxylase. It is approved as an API for the treatment of neurogenic orthostatic hypotension (NOH), a condition often associated with Parkinson's disease, multiple system atrophy, and pure autonomic failure. The specific stereochemistry of this intermediate is essential for producing the therapeutically active (S)-enantiomer of Droxidopa. As a specialized building block for a marketed cardiovascular/neurological drug, its primary industrial use is confined to pharmaceutical synthesis. It is not a general-purpose synthetic reagent. Handling requires standard precautions for laboratory chemicals.