Alfentanil Hydrochloride → Alfentanil

Participants

Reaction Steps

The alfentanil HCl obtained from step 7 is recrystallized from an HCl solution to give the final product as follows. 60.5 g of alfentanil HCl is placed into 2.5× amount of water (151 g H2O). To this is added 5.2 g activated charcoal and 10.4 g filtration aid (diatomaceous earth). Then 15.1 mL concentrated HCl is added (0.25 mL/g alfentanil HCl) and this is stirred until a slurry forms. This is followed by addition of 1 mL 1 N HCl/g alfentanil HCl (60.5 mL of 1 N HCl in this Example). This is chilled for over 2 hours and then filtered. The product is dried at approximately 40–55° C. until it is a constant weight. This final product is a monohydrate form of alfentanil HCl.

Provenance & Evidence