4-Phenyl-1-(2H)-phthalazinone

4-Phenyl-1-(2H)-phthalazinone corresponds to CAS 5004-45-5 and molecular formula C14H10N2O. PubChem assigns CID 219150, SMILES C1=CC=C(C=C1)C2=NNC(=O)C3=CC=CC=C32, and InChIKey XCJLBNVENUPHEA-UHFFFAOYSA-N. Its official synonyms include “4-phenyl-2-hydrophthalazin-1-one,” directly connecting the former catalog heading to this preferred Title.

The phthalazinone core contains a fused benzene and diazine-derived ring with adjacent nitrogen atoms. A carbonyl defines position 1, hydrogen is assigned to nitrogen at position 2, and a phenyl substituent occupies position 4. Together, the fused framework and external phenyl group account for fourteen carbons in C14H10N2O. PubChem encodes one neutral molecular component, without a counterion or stereochemical layer. The “2-hydro” and “1-(2H)-phthalazinone” forms describe the same lactam graph here, rather than a different salt or positional isomer. Exact CAS, SMILES, and InChI evidence therefore closes the naming difference while preserving the recorded connectivity. The mapping is unambiguous.

For an Rlavie inquiry, cite CAS 5004-45-5, CID 219150, and the preferred full name. State the requested quantity and request-specific information needed for the identity discussion. If the request begins from a drawing, attach a MOL or SDF structure file and compare the fused-ring carbonyl and phenyl connection with the recorded SMILES. InChIKey XCJLBNVENUPHEA-UHFFFAOYSA-N provides a final record-level checkpoint before the message is linked to this entry.