Abstract 2, 4-and 4, 6-Diamino-substituted pyrimidines are known for their biological activity in many therapeutic areas. A novel solid-phase synthesis of this class of compounds by nucleophilic aromatic substitution has been set up and the reactivity of differently substituted solid-supported pyrimidines with properly selected amines has been studied. Using this methodology a small library of diamino-substituted pyrimidines has been prepared.