Facile introduction of diverse substituents to 2-or 4-chloro-7H-pyrrolo [2,3-d] pyrimidines was examined with microwave-assisted nucleophilic substitution and Cu-catalyzed N-arylation. Microwave-assisted Cu-catalyzed N-arylation of pyrrolo[2,3-d]pyrimidines with various nucleophiles proceeded very well with diverse heteroaryl halides. Sequential microwave-assisted substitution provided good to excellent yields of 2,7-or 4,7-disubstituted pyrrolo[2,3-d]pyrimidines, with short reaction times and energy savings compared with conventional thermal heating. The diverse pyrrolo[2,3-d]pyrimidine derivatives are useful for screening drug candidates for various diseases.