is tautomer of 7H-purine purine 1H-purine 3H-purine 9H-purine C5H4N4 The 9H-tautomer of purine. 0 Gmelin:3120 CHEBI:35589 CAS:120-73-0 120.04360 9H-purine InChI=1S/C5H4N4/c1-4-5(8-2-6-1)9-3-7-4/h1-3H,(H,6,7,8,9) chebi_ontology 120.11222 Wikipedia:Purine Beilstein:606899 KDCGOANMDULRCW-UHFFFAOYSA-N c1ncc2nc[nH]c2n1