N-Substituted-2-amino-4 (3H)-7H-oxopyrrolo [2, 3-d] pyrimidine-5-carboxamides and their ribofuranosyl and 2′, 3′-dideoxyribofuranosyl derivatives were prepared as membrane permeable echiguanine analogs and tested for their ability to inhibit phosphatidylinositol (PI) 4-kinase. Compounds 5 and 6 were found to inhibit the enzyme approximately at the same level as echiguanines A and B. It is noteworthy that ribofuranosides 18, 19, and 20 and ...