To a solution of 2-[(1-methylethyl)oxy]-8-(methyloxy)-1H-purin-6-amine (37 mg, 0.166 mmol) in DMF (0.5 ml) was added potassium carbonate (55 mg, 0.398 mmol) followed by a solution of 1,1-dimethylethyl 4-(4-bromobutyl)-1-piperidinecarboxylate (58 mg, 0.181 mmol) in DMF (0.2 ml) and the mixture was stirred at room temperature for 72 hours. The mixture was diluted with dichloromethane (5 ml) and washed with water (5 ml). The layers were separated using a hydrophobic frit, the aqueous layer was extracted again with dichloromethane (5 ml) and the combined organic extracts were evaporated. The residue was dissolved in methanol (0.6 ml) and purified by MDAP (Method A). The appropriate fractions were combined and evaporated under a stream of nitrogen in a blowdown apparatus to give the title compound as a colourless gum (32 mg).
