1H-Pyrrolo[2,3-d]pyridazine

1H-Pyrrolo[2,3-d]pyridazine is the PubChem Title and IUPAC identity for CID 22564644. CAS 271-35-2 and formula C6H5N3 map to the same record. PubChem supplies SMILES C1=CNC2=CN=NC=C21 and InChIKey PCRSIUOCDHDRMN-UHFFFAOYSA-N. Its official synonyms include the catalog wording “1H-pyrrolo[3,2-d]pyridazine,” providing direct nomenclature evidence for this graph.

The fused bicyclic framework combines a pyrrole portion with a pyridazine ring. One nitrogen bears the indicated 1H hydrogen, while the pyridazine portion contains two adjacent nitrogens. Six carbon atoms and three nitrogens account for C6H5N3. The PubChem representation is a single neutral component, has no counterion, and carries no stereochemical markers. Fused-ring numbering can be expressed from the orientation used by the selected parent name or by an indexed synonym; here PubChem places both labels under the same CID. Exact CAS, formula, SMILES, InChI, and official synonym evidence therefore prevent the bracket variation from being treated as a different positional isomer.

For a structure-specific Rlavie inquiry, quote CAS 271-35-2, CID 22564644, and the preferred Title. Include the requested quantity and request-specific information for the identity discussion. When a drawn fused heterocycle is supplied, attach a MOL or SDF structure file and compare every ring closure and adjacent nitrogen position with the recorded SMILES. InChIKey PCRSIUOCDHDRMN-UHFFFAOYSA-N offers a compact final checkpoint before associating the message with this exact bicyclic entry.