1. 🧪 Organic Synthesis
Key Reagents and Protecting Groups
Used as protecting groups for hydroxyl and amino groups in the synthesis of complex molecules such as carbohydrates, steroids, and amino acids. It can also be used to activate carboxylic acids for subsequent reactions.

2. 💊 Pharmaceutical Industry
Synthesis of Pharmaceutical Intermediates
Used in the synthesis of sulfonamide drugs (such as sulfamethoxazole), antibiotics (such as cephalosporins), antiviral drugs (such as oseltamivir), and anti-tumor drugs. It is also an intermediate in the synthesis of drugs such as diphenoxylate (for treating diarrhea).

3. 🌾 Agrochemical Industry
Key Synthesis Intermediate
A key intermediate in the synthesis of sulfonylurea herbicides (such as bensulfuron-methyl) and other pesticides such as mesotrione and metalaxyl-M.

4. 🔬 Polymer Materials
Catalyst and Crosslinking Agent
Used as an initiator (catalyst) in cationic polymerization reactions, and also as a crosslinking agent in the preparation of high-temperature and corrosion-resistant polymer materials.

5. 🎨 Dyes and Fragrances
Intermediate and Catalyst
Used as a reagent for introducing sulfonic acid groups in the manufacture of disperse dyes, azo dyes, and acid dyes. It can also catalyze esterification reactions in fragrance synthesis.

6. ⚗️ Analytical Chemistry
Derivatization Reagent for Chemical Analysis
Used as a derivatization reagent for the detection of alcohols, amines, and phenols in gas chromatography (GC) or high-performance liquid chromatography (HPLC).