Hydrochloric Acid → Duloxetine Hydrochloride

Participants

Reaction Steps

Sodium hydroxide solution (30% w/v; 15.5 ml) was added to a stirred suspension of duloxetine maleate (20 g, 0.0484 mole) in a mixture of toluene (200 ml) and deionised water (200 ml) at 15° to 20° C. to attain a pH of 12. The mixture was stirred for 10 minutes. Toluene layer was separated and aqueous layer was extracted with toluene (100 ml). The combined toluene layer was washed with deionised water (2×100 ml) and concentrated under vacuum to obtain duloxetine free base as an oily mass. The duloxetine free base so obtained was stirred in ethyl acetate (140 ml) and ethanolic hydrochloric acid (8.52 g; 0.063 mole; 27% w/w; 1.3 mole equivalent) at 10° to 15° C. The mixture was stirred at 10° to 15° C. for 30 minutes and subsequently at 20° to 25° C. for 3 hours. The reaction mixture was divided into two parts namely Part A and Part B.

Provenance & Evidence