"One Pot" Synthesis of 2-Substituted 9-(2'-Hydroxy-3'-aminopropyl)-8-azahypoxanthines and 8-Azaadenines [5-Substituted 3-(2'-Hydroxy-3'-aminopropyl)-7-amino and 7-hyroxy- 3H-1,2,3-triazolo[4,5-d]pyrimidines]