In the sophisticated realm of organic synthesis and biochemical research, the precise selection and utilization of reagents are fundamental to achieving successful outcomes. Fmoc-Thr(tBu)-OH, a key player in peptide chemistry, exemplifies such a critical reagent. This article serves as a comprehensive guide for chemists and procurement specialists, detailing the chemical properties, optimal handling procedures, and strategic procurement considerations for this indispensable Fmoc-protected amino acid derivative.

Fmoc-Thr(tBu)-OH, formally known as N-(9-fluorenylmethoxycarbonyl)-O-tert-butyl-L-threonine, is a vital component in solid-phase peptide synthesis (SPPS), particularly within the Fmoc-based methodology. Its molecular structure is characterized by the presence of the Fmoc group protecting the alpha-amino functionality and a tert-butyl (tBu) group safeguarding the side-chain hydroxyl of threonine. The Fmoc group is favored for its facile removal under mild basic conditions, a crucial attribute for preserving the integrity of sensitive peptide chains during synthesis. The t-butyl group offers robust protection against side reactions, ensuring that the threonine residue is incorporated accurately. Its stability during the standard Fmoc deprotection steps, coupled with its clean removal using acidic reagents like TFA at later stages, makes it highly advantageous.

From a chemist's perspective, understanding the physical and chemical properties of Fmoc-Thr(tBu)-OH is essential for its effective use. Typically supplied as a white powder, its purity is a critical specification, usually determined by HPLC analysis, with values often exceeding 99%. Key properties include its molecular formula (C23H27NO5) and molecular weight (approximately 397.5 g/mol). Its solubility characteristics are also important; it generally exhibits good solubility in polar organic solvents such as DMSO and ethanol, which are commonly employed in SPPS. Proper storage, typically at low temperatures (e.g., 4°C or -20°C), is recommended to maintain its stability and efficacy over time.

For procurement professionals, sourcing Fmoc-Thr(tBu)-OH involves more than just finding the lowest price. While competitive pricing is certainly a factor, reliability of supply and consistent quality are paramount, especially for large-scale manufacturing. Identifying experienced manufacturers and suppliers, who can provide detailed Certificates of Analysis (CoA) and support bulk orders, is crucial. Many researchers and companies opt to buy from established suppliers, including those based in China, to leverage competitive pricing and extensive manufacturing capabilities. When placing an order, ensure the CAS number (71989-35-0) is correctly specified. By understanding these aspects—from chemical nuances to strategic sourcing—chemists and procurement teams can ensure they have a dependable supply of high-quality Fmoc-Thr(tBu)-OH for all their synthesis needs.