Sodium Hydroxide → Sotalol

Participants

Reaction Steps

--A solution of racemic sotalol (24.5 g., 0.09 mole) (obtained by neutralizing sotalol hydrochloride in ethanol with a mole equivalent of concentrated sodium hydroxide, concentration and extraction of the free base in acetonitrile) in 200 ml. of hot isopropanol was mixed with 13.7 g (0.09 mole) of 1-mandelic acid. On cooling, an optically enriched fraction, 26.0 g., m.p. 125-140°, [α]D25 -27.2°, of the d-sotalol·1-mandelate salt was obtained. Crystallization from isopropanol (300 ml.) afforded 18.7 g., m.p. 139-145.5°, [α]D25 -25.4°. Further recrystallization of this material from 1:1 isopropanol-absolute ethanol provided d-sotalol.1-mandelate as white fluffy needles, m.p. 154.5≥156°, [α]D25 -14. 2°.

Provenance & Evidence