Zopiclone → (S)-Zopiclone Besylate

Participants

Reaction Conditions

Reaction Steps

A 2000 mL reactor was charged with 10.0 g (S)-zopiclone and 400 mL tetrahydrofuran (THF). The contents were heated to 35° C. Into a 1000 mL reactor was charged 4.4 g benzenesulfonic acid and 400 mL THF, and stirred until a solution was formed. The acid solution was transferred slowly to the zopiclone solution. The reaction was cooled to 15° C. and stirred for 18 hr at 20-25° C. The reactor slurry was filtered and washed with THF in an appropriate filter. The wet cake was dried under vacuum at 60-65° C. and packaged in an appropriate container. Isolated yield=92.7%.

Provenance & Evidence