Cholesteryl chloride

Cholesteryl chloride (CAS 910-31-6), also known as cholesterol chloride and 3-chlorocholest-5-ene, is a reactive cholesterol derivative used primarily as a synthetic building block in pharmaceutical and biotechnology research.

Its activated C-3 position makes it a key starting material for introducing cholesterol moieties into complex molecules during multi-step synthesis. In pharmaceutical development, it is used to synthesize cholesterol-conjugated compounds.

These include prodrugs and lipid-based drug delivery systems designed to improve membrane permeability and cellular uptake. Biotechnology researchers employ it to prepare cholesterol-tagged oligonucleotides and siRNA conjugates.

Cholesterol attachment enhances in vivo stability and tissue targeting in these applications. It also serves as an intermediate in the preparation of steroid derivatives and cholesterol esters used as reference standards.

These derivatives are often utilized as analytical reagents in QC workflows. Specialty lipid formulators use it to introduce cholesterol anchors into liposomal and nanoparticle systems currently under development.

Cholesteryl chloride is supplied as a white to off-white crystalline solid. It is available primarily in research and development quantities, with purity grades typically ranging from 95% to 98%+ by GC or HPLC.

Packaging is generally offered in gram to kilogram quantities under inert atmosphere conditions to maintain stability. This ensures the material meets the rigorous demands of laboratory and pilot-scale synthesis projects.