In the competitive landscape of pharmaceutical research and development, the selection of chemical intermediates with precise specifications is non-negotiable. Bis(2-methyl-2-propanyl) N,N'-bis[(9H-fluoren-9-ylmethoxy)carbonyl]-L-cystinate, commonly known as (Fmoc-Cys-OtBu)2 and identified by CAS Number 139592-37-3, is a prime example of such a crucial compound. For scientists and procurement managers aiming to buy this pharmaceutical intermediate, understanding its key specifications, particularly when sourced from China manufacturers, is vital for successful outcomes.

The chemical identity of (Fmoc-Cys-OtBu)2 is defined by its molecular formula C44H48N2O8S2 and a molecular weight of approximately 796.99 g/mol. These fundamental parameters are consistent across all reputable suppliers. However, the most critical specification for researchers is purity. Most high-quality (Fmoc-Cys-OtBu)2 is supplied with a purity of ≥98%, often verified by analytical techniques such as HPLC or GC. This high purity is indispensable for achieving accurate results in complex syntheses, particularly in peptide chemistry where even minor impurities can lead to unwanted side products or reduced yields. When you buy from a China manufacturer, verifying this purity through their provided Certificate of Analysis (COA) is a standard and necessary step.

Beyond purity, understanding the physical form and storage conditions is crucial. (Fmoc-Cys-OtBu)2 typically presents as a white crystalline powder. Its stability is best maintained when stored under refrigeration, typically between 0-5°C, in a tightly sealed container to prevent moisture ingress. A reliable China supplier will ensure appropriate packaging and shipping conditions to maintain product integrity during transit. For procurement professionals, this means inquiring about temperature-controlled shipping options if necessary, to guarantee the intermediate arrives in optimal condition for immediate use.

The applications of (Fmoc-Cys-OtBu)2 are primarily within advanced organic synthesis and pharmaceutical intermediate roles. It serves as a protected derivative of cysteine, frequently used in solid-phase peptide synthesis (SPPS) for the introduction of disulfide-bonded peptides, which are critical for many therapeutic proteins and peptides. Its specific chemical structure makes it a valuable building block for medicinal chemists developing new drug candidates. When procurement managers look to buy this compound, they are often seeking a reliable partner who can consistently supply this high-specification intermediate, thereby ensuring the smooth progression of their research and development projects.

In summary, when sourcing (Fmoc-Cys-OtBu)2, paying close attention to purity (≥98%), physical form, recommended storage, and accompanying documentation like COAs from China manufacturers is essential. These specifications are not merely technical details but are fundamental to the success of pharmaceutical R&D, making informed purchasing decisions a strategic advantage.