Zopiclone → Eszopiclone

HRID 507802Notes

Reaction equation

HRID 507802 reaction equation
[CH3:1][N:2]1[CH2:7][CH2:6][N:5]([C:8]([O:10][CH:11]2[N:20]([C:21]3[CH:22]=[CH:23][C:24]([Cl:27])=[CH:25][N:26]=3)[C:18](=[O:19])[C:13]3[N:14]=[CH:15][CH:16]=[N:17][C:12]2=3)=[O:9])[CH2:4][CH2:3]1.C(OC(=O)C(C(C(OC(=O)C1C=CC=CC=1)=O)O)O)(=O)C1C=CC=CC=1>C(Cl)Cl>[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:22]=[CH:23][C:24]([Cl:27])=[CH:25][N:26]=3)[C:18](=[O:19])[C:13]3[N:14]=[CH:15][CH:16]=[N:17][C:12]2=3)=[O:9])[CH2:4][CH2:3]1

Participants

4

Reactant 2

HCID 5735ZopicloneHCID 10284017HCID 10284017, compound

Product 1

HCID 969472Eszopiclone

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Accordingly, racemic zopiclone is preferably reacted with a resolving agent (+)-O,O′-dibenzoyl tartaric acid in methylene dichloride at room temperature to obtain the diastereomeric salt (Scheme IV) which is crystallized from acetonitrile followed by conversion into eszopiclone by treating with an inorganic base, such as NaOH. Eszopiclone thus obtained has a purity above 99%. Eszopiclone is recrystallized from ethyl acetate to obtain the product with purity of 99.9%

Workup

  1. customto obtain the diastereomeric salt (Scheme IV) which
  2. customis crystallized from acetonitrile
  3. additionby treating with an inorganic base, such as NaOH

Sources & evidence

ORD record
ord-2cbdcbc8be4a42369650ca5dc097ab87
Source dataset
uspto-grants-2010_08
Patent number
US07786304B2

Reaction notes

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