title: Solid-phase synthesis of 7-substituted 3H-imidazo[2,1-i]purines.
abstract: A method for solid-supported synthesis of N,N-disubstituted (3H-imidazo[2,1-i]purin-7-yl)methyl amines has been developed. The key features of this library synthesis are: (i) immobilization of commercially available N6-benzoyl-5'-O-(4,4'-dimethoxytrityl)-2'-deoxyadenosine 3'-(2-cyanoethyl N,N-diisopropylphosphoramidite) by phosphitylation to a hydroxyl-functionalized support, (ii) quantitative conversion of the deprotected adenine base to 3H-imidazo[2,1-i]purine-7-carbaldehyde with bromomalonaldehyde in DMF in the presence of formic acid and 2,6-lutidine, (iii) reductive amination of the formyl group followed by N-alkylation or N-acylation, and (iv) release from the support by acidolytic cleavage of the N-glycosidic bond. Steps (ii) and (iii) have been optimized in some detail by using (adenin-9-yl)acetic acid anchored to a Phe-Wang resin as a model compound.
authors.affiliation: Department of Chemistry, University of Turku, Turku, FIN-20014, Finland.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Karskela
authors.forename: Harri
authors.initials: H
authors.lastname: Lönnberg
mesh_terms: D015394:Molecular Structure; D011687:Purines / Q000138:chemical synthesis*
chemical_list: D011687:Purines