Sodium Hydroxide → Duloxetine

Participants

Reaction Steps

The duloxetine hydrochloride (5 g) obtained in step A) was treated with 1 N sodium hydroxide (0.72 g; 18 ml) and extracted with toluene (50 ml). The toluene layer was evaporated to obtain the free base of duloxetine (4.4 g). The free base of duloxetine was loaded on a silica gel column (dry slurry with 10 g of silica gel) with dichloromethane. The elution was started with 0.5% v/v of methanol in dichloromethane and the free base of duloxetine was eluted with 1% v/v methanol in dichloromethane, and the eluted fractions were concentrated under vacuum to obtain the free base of duloxetine. The impurity of Formula II was eluted with 10% v/v methanol in dichloromethane and the eluted fractions were concentrated under vacuum to obtain the title compound.

Provenance & Evidence