title: New and practical method for synthesis of 1- and 1,3-substituted xanthines.
abstract: [reaction: see text] A new and practical method for the synthesis of 1- and 1,3-substituted xanthines is reported. Direct base-promoted condensation of the imidazole precursor 1 with carbamates 2 gives 1-substituted 7-PMB xanthines 7 in good yields. Alkylation of these derivatives or their potassium salts proceeds under mild conditions to give functionalized 1,3-substituted 7-PMB xanthines 9 in good to excellent yields. The obtained 7-PMB-protected derivatives can be readily deprotected to give the parent 1- and 1,3-substituted xanthines.
authors.affiliation: Department of Synthetic Chemistry, Schering-Plough Research Institute, 1011 Morris Avenue, Union, New Jersey 07083, USA.
authors.forename: Ilia A
authors.initials: IA
authors.lastname: Zavialov
authors.forename: Vilas H
authors.initials: VH
authors.lastname: Dahanukar
authors.forename: Hoa
authors.initials: H
authors.lastname: Nguyen
authors.forename: Cecilia
authors.initials: C
authors.lastname: Orr
authors.forename: Fucheng
authors.initials: F
authors.lastname: Zhang
authors.forename: David R
authors.initials: DR
authors.lastname: Andrews
mesh_terms: D000478:Alkylation; D002219:Carbamates / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D014970:Xanthines / Q000138:chemical synthesis*
chemical_list: D002219:Carbamates; D007093:Imidazoles; D014970:Xanthines