having the nitrogen atoms in positions 1 and 3

Compounds containing elements of Groups 5 or 15 of the Periodic Table > Phosphorus compounds > Heterocyclic compounds, e.g. containing phosphorus as a ring hetero atom > having two nitrogen atoms as the only ring hetero atoms > Six-membered rings > having the nitrogen atoms in positions 1 and 3

Compounds containing elements of Groups 5 or 15 of the Periodic Table > Phosphorus compounds (sugar phosphates C07H11/04; nucleotides C07H19/00, C07H21/00; nucleic acids C07H21/00) > Heterocyclic compounds, e.g. containing phosphorus as a ring hetero atom > having two nitrogen atoms as the only ring hetero atoms > Six-membered rings > having the nitrogen atoms in positions 1 and 3