Urea-functionalized nucleobases and nucleosides have emerged as versatile compounds with potential applications in a wide range of fields. Conventionally, the synthesis of urea involves the reaction of isocyanates with nucleobases and nucleosides. In contrast, this study presents a novel and efficient one-pot method for the synthesis of urea-substituted nucleobases and nucleosides without the use of isocyanates. The reaction was carried out in the presence of DMAP and TBPP, resulting in moderate to good yields of various urea-substituted nucleobases and nucleosides. Notably, N6-(N-threonyl-carbonyl)adenosine was also synthesized using this method. Furthermore, the synthesized compounds with adenine scaffold were evaluated for their binding affinity to adenosine receptors, but none of them exhibited binding, indicating a need for further modifications. These findings hold great promise for the facile synthesis of urea-functionalized nucleobases and nucleosides with potential applications in various fields.