title: Symmetrically and unsymmetrically bridged methylenebis(allopurinols): synthesis of dimeric potential anti-gout drugs.
abstract: Liquid-liquid phase transfer alkylation of 4-methoxy-pyrazolo[3,4-d]-pyrimidine (1a) with a dichloromethane/dibromomethane mixture (3:1, v/v) gave the regioisomeric methylenebis(heterocycles) 3a-5a. These were converted by dilute aqueous sodium hydroxide containing dimethylsulfoxide (DMSO) at concentrations between 0 and 60 vol-% into the methylenebis(allopurinols) 3b-5b by nucleophilic SNAr reactions at C(4). The effect of DMSO on the reaction kinetics was investigated.
authors.affiliation: Organische Chemie I-Bioorganische Chemie, Institut für Chemie, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 7, D-49069 Osnabrück, Germany. Helmut.Rosemeyer@uos.de
authors.forename: Helmut
authors.initials: H
authors.lastname: Rosemeyer
authors.forename: Martina
authors.initials: M
authors.lastname: Anders
authors.forename: Frank
authors.initials: F
authors.lastname: Seela
mesh_terms: D000493:Allopurinol / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D002247:Carbon Isotopes; D006074:Gout Suppressants / Q000138:chemical synthesis* / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry; D007700:Kinetics; D008958:Models, Molecular; D011522:Protons; D012399:Rotation; D013237:Stereoisomerism
chemical_list: D002247:Carbon Isotopes; D006074:Gout Suppressants; D006571:Heterocyclic Compounds; D011522:Protons; D000493:Allopurinol