SYNTHESIS OF PYRROLO[2,3-D]PYRIMIDINES THAT ARE STRUCTURALLY RELATED TO METHYLATED GUANOSINES FROM TRANSFER-RNA AND THE NUCLEOSIDE Q ANALOGS, PREQ(0) AND PREQ(1)

The N-3- and N-2-methylated analogs of several 5-substituted eta-D-rib ofuranosyl)pyrrolo[2,3-d]pyrimidin-4-ones were synthesized from 5-cyan o-2,4-dichloro-7-(2,3,5-tri-(O>$) over bar under etyl-beta-D-ribofuran osyl)pyrrolo[2,3-d]pyrimidine (10) These compounds are analogs of nucl eoside Q that are methylated in a manner similar to some of the natura lly occurring methylated guanosines.