A novel route has been found for the synthesis of pyrimido[5',4':4,5]pyrrolo[2,1-c][1,4]oxazines. They are promising reagents for the preparation of pyrrolo[2,3-d]pyrimidine-6-carboxylic acid amides which contain a 3-amino-2-hydroxypropyl substituent in position 7 of the heterocyclic ring.