title: Donepezilium oxalate trihydrate, a therapeutic agent for Alzheimer's disease.
abstract: Donepezil, a cholinesterase inhibitor with good central nervous system penetration, has been crystallized as a tertiary amine salt with a disordered oxalate anion to give the title compound, (R,S)-1-benzyl-4-[(5,6-dimethoxy-1-oxoindan-2-yl)methyl]piperidinium hydrogen oxalate trihydrate, C24H30NO3+.C2HO4-.3H2O. The indanone and piperidine ring planes are inclined at an angle of 33.4 (1) degrees. A comparison is made with the piperidinium cation bound in acetylcholinesterase in the solid state. The methylene units bridging the indanone-piperidine-benzyl groups determine the molecular shape and conformational features. The structure is stabilized mainly by O-H...O and N-H...O hydrogen bonds, with water molecules mediating interactions between oxalate anions and donepezilium cations.
authors.affiliation: Laboratory of X-ray Crystallography, Indian Institute of Chemical Technology, Hyderabad 500 007, India. ravikumar_iict@yahoo.co.in
authors.forename: K
authors.initials: K
authors.lastname: Ravikumar
authors.forename: B
authors.initials: B
authors.lastname: Sridhar
authors.forename: D G
authors.initials: DG
authors.lastname: Sathe
authors.forename: A V
authors.initials: AV
authors.lastname: Naidu
authors.forename: K D
authors.initials: KD
authors.lastname: Sawant
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy; D002626:Chemistry, Pharmaceutical; D002800:Cholinesterase Inhibitors / Q000737:chemistry* / Q000627:therapeutic use; D018360:Crystallography, X-Ray; D000077265:Donepezil; D006860:Hydrogen Bonding; D007189:Indans / Q000737:chemistry* / Q000627:therapeutic use; D015394:Molecular Structure; D010880:Piperidines / Q000737:chemistry* / Q000627:therapeutic use; D014867:Water / Q000737:chemistry
chemical_list: D002800:Cholinesterase Inhibitors; D007189:Indans; D010880:Piperidines; D014867:Water; D000077265:Donepezil