Reductive cyclization of 6-(1-cyanoalkyl)-5-nitropyrimidines leads to 7-alkyl-5H-pyrrolo[3,2-d]pyrimidines. The presence of two alkyl substituents at the cyanomethyl group results in formation of 6-amino-7,7-dialkyl-7H-pyrrolo-[3,2-d]pyrimidines. By this method 7-(2,3-dihydroxypropyl)-2,4-dimethoxy-5H-pyrrolo[3,2-d]pyrimidine was prepared as an intermediate for the preparation of 9-deaza analogues of DHPA and related compounds.