Zolpidem → Zolpidem methanesulfonate

Participants

Reaction Steps

One gram of zolpidem free base is dissolved in 10 ml of ethanol at 50° C. Then 0.313 g (a molar equivalent) of methane sulfonic acid is added at this temperature, the mixture is stirred for 5 minutes and evaporated to dryness under reduced pressure. The residue is treated with 10 ml of acetone, the remaining solid is filtered off and washed with 5 ml of acetone and dried in vacuum oven at 40° C. to yield zolpidem methanesulfonate. A representative DSC curve is shown in FIG. 12.

Provenance & Evidence