The protected 2,6-di(methoxyacetamido)purine (IV) (1.55 kg, 2.20 mol) was dissolved in methanol (3.6 L) with stirring and warmed to 46°-48° C. A solution of sodium methoxide (30 g, 95%, 0.55 mol, in 250 mL methanol) was added and the solution was warmed to 61° C. The reaction was completed in about 1 hour (tlc) at which time the product started to precipitate. The mixture was allowed to cool to 30° C. and then refrigerated overnight. The product was collected, washed with ice-cold methanol (800 mL) and air-dried to give the title compound (V) 823 g (68%), mp 60°-62° C.
