To a solution of 2-({2-[(1-methylethyl)oxy]ethyl}oxy)-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine (165 mg) in dry methanol (17 ml) was added 4.0M hydrogen chloride in 1,4-dioxane (2.95 ml) in one go. The reaction was left to stir at room temperature for 5 hours. The reaction was neutralised by the addition of 2.0M sodium hydroxide solution and concentrated in vacuo to give an off-white solid. The solid was triturated in water, and filtered under vacuum, washing with more water, to give an off-white solid (120 mg).
