DMSO appears in selected statin-intermediate routes as a solvent option or as a reagent in an oxidation option. The relevant question is which intermediate is being made and what transformation occurs.
Two different roles
A rosuvastatin-related patent lists DMSO among possible process solvents. A separate statin-intermediate disclosure describes a Kornblum oxidation option for forming an aldehyde using DMSO.
In the first case, DMSO is considered as a medium. In the second, it participates chemically in the transformation. A solvent listed as an option is not the same evidence as a worked production example, so route selection should use the relevant experimental detail.
Tie quality to the transformation
For an aldehyde-forming step, compare conversion, remaining starting material and oxidation-related impurities. For solvent use elsewhere, assess the actual reaction, isolation and any stereochemical or solid-form requirements.
Water and other impurity limits should follow the chosen step. Include solvent recovery and downstream removal when comparing supplies. Strong-base systems need specific compatibility review; sodium hydride/DMSO mixtures have documented explosion hazards.
For sourcing, give YUJI the intermediate step and agreed DMSO specification rather than only the statin name.