(S)-2-Acetamido-3-(4-hydroxyphenyl)-N-methylpropanamide (Ac-Tyr-NHMe) is a key chiral amino acid derivative, widely used in pharmaceutical research, peptide synthesis, and biochemical studies. As a protected L-tyrosine analog, it serves as a critical building block for synthesizing bioactive peptides, enzyme inhibitors, and receptor ligands, especially those targeting tyrosine-related signaling pathways. In peptide chemistry, it acts as a model substrate for studying protease activity and peptide bond hydrolysis, aiding in the development of protease inhibitors for diseases like cancer and inflammation. In pharmaceutical development, it is used to synthesize tyrosine-derived drugs, including analgesics, antihypertensives, and anti-inflammatory agents, leveraging its chiral purity and structural stability. Additionally, it functions as a research tool in chemical biology for probing protein–ligand interactions and studying the metabolism of aromatic amino acids. Its high solubility in organic solvents and compatibility with standard peptide synthesis protocols make it a versatile reagent in academic and industrial laboratories.

GHS Classification: Warning Hazard Statements: H315 (Causes skin irritation); H319 (Causes serious eye irritation) This compound is a low-toxicity chiral amide with minimal acute toxicity (oral LD50 >5000 mg/kg in rats). Direct skin contact may cause mild redness, itching, or dryness due to moderate irritant properties; prolonged or repeated exposure could lead to dermatitis. Eye contact can result in stinging, tearing, and conjunctivitis, requiring immediate rinsing. Inhalation of dust may irritate the respiratory tract, causing mild coughing or throat discomfort. No evidence of carcinogenicity, mutagenicity, or reproductive toxicity has been reported under normal handling conditions. Handle in a fume hood with nitrile gloves, safety goggles, and a dust mask (N95). Avoid contact with strong acids and oxidizing agents. In case of skin contact, wash thoroughly with soap and water; for eye exposure, rinse continuously with water for 15 minutes and seek medical advice if irritation persists. Store in a cool, dry place away from light. Dispose of waste per local hazardous waste regulations.