Hydrochloric Acid → Terbinafine Hydrochloride

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Reaction Steps

14.1 g crude terbinafine (39.9 mmol theoretical, example 6) is dissolved in 94 ml methyl ethyl ketone (MEK) and then 3.9 ml (0.0399 mol) of 32% aqueous hydrochloric acid is added dropwise. The resulting suspension is stirred for 30 minutes and then concentrated to a small volume, using a rotavapor to azeotropically distil off the water. The initial volume is restored with chilled MEK. After stirring for 2 hours at 20° C., the precipitate is filtered, washed with 2×11 ml MEK and dried to constant weight under a heat lamp. 8.7 g (66.4% yield) of terbinafine-HCl are obtained as a white solid with purity of 99.3% (HPLC A %).

Provenance & Evidence