1-[4-(Azidoacetyl)phenyl]-1H-pyrazole-3,4-dicarboxylic acid dimethyl ester is a multifunctional heterocyclic compound bearing both azide and pyrazole moieties, widely utilized in bioconjugation, pharmaceutical intermediate synthesis, and material chemistry. Its azide group enables efficient copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reactions, serving as a key reagent for labeling biomolecules (proteins, peptides, nucleic acids) and preparing bioconjugates with high selectivity and mild reaction conditions. In pharmaceutical research, it acts as a critical intermediate for synthesizing pyrazole-based drugs, such as anti-inflammatory, analgesic, and antitumor agents, via modification of ester and azide groups. In materials science, it is employed to functionalize polymers, nanoparticles, and surfaces, enhancing their biocompatibility and targeting ability. Additionally, it is used in chemical biology studies for probe development and target identification, owing to its unique reactivity and structural versatility.

GHS Classification: Warning Hazard Statements: H302 (Harmful if swallowed); H312 (Harmful in contact with skin); H332 (Harmful if inhaled); H315 (Causes skin irritation); H319 (Causes serious eye irritation) This organic azide compound is harmful by oral, dermal, and inhalation routes, with potential acute toxicity. Direct skin contact may cause redness, itching, and irritation; eye exposure leads to stinging, tearing, and conjunctivitis. Inhalation of dust or fumes can irritate the respiratory tract, causing coughing, shortness of breath, or dizziness. It is heat- and shock-sensitive, and may decompose violently under strong impact, friction, or high temperature, releasing toxic nitrogen oxides (NO?). No evidence of carcinogenicity or mutagenicity has been reported. Handle in a fume hood with nitrile gloves, safety goggles, and an N95 respirator. Avoid contact with strong acids, reducing agents, and heavy metals. Store in a cool, dry place away from heat and light. Dispose of waste per hazardous waste regulations, avoiding release into the environment.