Water → Eszopiclone

Participants

Reaction Conditions

Reaction Steps

A three-neck 250 mL flask was charged with (+)-zopiclone-D-malate (10 g, 93% ee), 20 mL water and 150 mL of EtOAc. The reaction mixture was heated in an oil bath to 30-40° C. An aqueous K2CO3 solution (40%, 8 g) was added slowly over 5 min. The mixture was then heated to 60-65° C. and the organic phase was isolated and washed with 100 mL water. The mixture was polish filtered, rinsed with EtOAc (20 mL) and concentrated to 70-80 mL. The resulting slurry was cooled and held for 2 h at 0-5° C. The crystal product was isolated by filtration and was washed with cold EtOAc (20 mL, 0-5° C.). The white product was dried at 30-40° C./28 mmHg over 6-12 h to give (+)-zopiclone (6.4 g 86.2%, 99.9% ee).

Provenance & Evidence