Abstrait

Reductive step for preparation of rosiglitazone

Ales Halama, Josef Jirman, Petr Lustig, Jan Rymes

An improved process has been developed for the production of rosiglitazone based on reductive transformation of substituted 5-benzylidenethiazolidin- 2,4-dione. Sodiumborohydridewas usedas reducingagent anddivalent cobalt complexwith dimethyglyoximas catalyst.Reaction temperatures as well as dosagemodes of the reducing agent and catalyst have been identified as significantlyimportant pa-rameters of the process. The discussed procedure ensures veryhigh conversions and yields of the reductive transformation.