DMSO is used as a reaction solvent in certain spironolactone intermediate routes. One documented application is the conversion of a protected steroid 17-ketone into an epoxide using a sulfonium reagent and base.
Spironolactone (CAS 52-01-7) is obtained through further transformations. DMSO use in this earlier stage can therefore create a recurring solvent requirement at a plant making the intermediate.
Its role in the intermediate reaction
In the described chemistry, base generates a sulfur ylide from trimethylsulfonium bromide. The ylide reacts with the steroid carbonyl group to form the epoxide. DMSO provides the reaction medium, while the sulfonium reagent supplies the added methylene unit.
The two materials have different roles. Trimethylsulfonium bromide is also distinct from trimethylsulfoxonium bromide (TBM), so their names should be kept separate in technical discussions and purchasing documents.
Public manufacturing records identify a DMSO-containing steroid-intermediate operation followed by a separate chloranil treatment in acetone. DMSO's presence in the earlier operation does not make it the oxidant for that later treatment.
Match water content to the step
For a base- and ylide-containing reaction, water content should be controlled to the established process requirement. Check the incoming DMSO and protect it from moisture during storage and charging.
There is no single water limit for all spironolactone chemistry. A different published route uses DMSO with added water during a conversion toward canrenone. The solvent specification must follow the actual intermediate reaction.
When evaluating another DMSO source, compare reaction progress, intermediate impurities, isolated yield and work-up behavior. The complete base-containing mixture also needs compatibility and thermal assessment.
DMSO remaining after the reaction is managed through downstream work-up and residual-solvent controls. Its use in this step does not make it the source of spironolactone's acetylthio group.
For a sourcing enquiry, tell YUJI which intermediate step uses DMSO and provide the required solvent specification and packaging.
Technical references
Further reading: DMSO in Corey–Chaykovsky Epoxidation.