Hydrochloric Acid → N-({6-[(2,2-Diphenylethyl)amino]-9H-purin-2-yl}methyl)-N'-[2-(1-piperidinyl)ethyl]urea

A solution of N-({6-[(2,2-diphenylethyl)amino]-9-tetrahydro-2H-pyran-2-yl-9H-purin-2-yl}methyl)-N′-[2-(1-piperidinyl)ethyl]urea (300 mg, 0.51 mmol) (Preparation 4) in methanol (150 ml) was treated with aqueous hydrochloric acid (2M, 100 ml). The reaction mixture was stirred at room temperature for 2 hours. The solvent volume was then reduced to 100 ml by evaporation under reduced pressure. Saturated aqueous sodium hydrogen carbonate solution (50 ml) and ethyl acetate (200 ml) were added. The two phases were separated. The organic layer was washed with saturated aqueous sodium chloride solution (100 ml), dried (anhydrous magnesium sulphate) and evaporated to give the title compound as a solid (255 mg).