Few examples of new heterocyclic 1-deazapyrimido[1,2,3-cd]purine derivatives were synthesized by intramolecular cyclization of methyl 7-(oxiran-2-ylmethyl)-7H-pyrrolo[2,3-d]pyrimidine-6-carboxylates. The latter were obtained by iodolactonization of 7-allylpyrrolo[2,3-d]pyrimidine-6-carboxylic acids