1-hydroxybenzotriazole

1-Hydroxybenzotriazole (CAS 2592-95-2), commonly known as HOBt, is a coupling reagent and catalyst used in peptide synthesis and pharmaceutical manufacturing. It suppresses racemization and activates carboxyl groups during amide bond formation.

This reagent directly impacts the purity and yield of active pharmaceutical ingredients. HOBt is a standard reagent in solid-phase and solution-phase peptide synthesis, where it forms active esters that drive efficient coupling of amino acids.

In pharmaceutical intermediate manufacturing, it is used alongside carbodiimide reagents such as EDC or DCC to improve coupling efficiency. This process helps reduce epimerization in complex molecule assembly during API production.

Contract research and development organizations rely on HOBt for small-scale synthesis of peptide-based drug candidates. Stereochemical integrity is a critical quality parameter that this reagent helps maintain throughout the process.

It also supports the production of peptide libraries in drug discovery workflows. Consistent coupling performance across large compound sets is required for these high-throughput applications in modern medicinal chemistry.

HOBt is supplied as a white to off-white crystalline powder, typically in anhydrous form or as a monohydrate. The hydrated form is preferred for safer handling in bulk quantities during industrial operations.

Standard grades include anhydrous and hydrate variants meeting pharmaceutical research specifications. It is available in laboratory quantities through to multi-kilogram lots for commercial API manufacturing campaigns.