Water → Eszopiclone

HRID 1634034Notes

Reaction equation

[CH3:1][N:2]1[CH2:7][CH2:6][N:5]([C:8]([O:10][C@@H:11]2[N:20]([C:21]3[CH:26]=[CH:25][C:24]([Cl:27])=[CH:23][N:22]=3)[C:18](=[O:19])[C:17]3[C:12]2=[N:13][CH:14]=[CH:15][N:16]=3)=[O:9])[CH2:4][CH2:3]1.C([O-])(=O)[C@@H](CC([O-])=O)O.O.C([O-])([O-])=O.[K+].[K+]>CCOC(C)=O>[CH3:1][N:2]1[CH2:7][CH2:6][N:5]([C:8]([O:10][C@@H:11]2[N:20]([C:21]3[CH:26]=[CH:25][C:24]([Cl:27])=[CH:23][N:22]=3)[C:18](=[O:19])[C:17]3[C:12]2=[N:13][CH:14]=[CH:15][N:16]=3)=[O:9])[CH2:4][CH2:3]1

Participants

Conditions

Temperature: 35 °C

Procedure

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).

Workup

temperatureThe mixture was then heated to 60-65° C.
customthe organic phase was isolated
washwashed with 100 mL water
filtrationfiltered
washrinsed with EtOAc (20 mL)
concentrationconcentrated to 70-80 mL
temperatureThe resulting slurry was cooled
customThe crystal product was isolated by filtration
washwas washed with cold EtOAc (20 mL, 0-5 ° C.)
customThe white product was dried at 30-40° C./28 mmHg over 6-12 h

Sources & evidence

ORD record: ord-2785ebf3b96e495aada6c2816a3c1a9d
Source dataset: uspto-grants-2003_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06506753B2

Reaction notes

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