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Names | |
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Preferred IUPAC name Phthalazine [2] | |
Other names Benzo-orthodiazine 2,3-Benzodiazine Benzo[d]pyridazine | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.005.422 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C8H6N2 | |
Molar mass | 130.150 g·mol−1 |
Appearance | Pale yellow needles |
Melting point | 90 to 91 °C (194 to 196 °F; 363 to 364 K) |
Boiling point | 315 to 317 °C (599 to 603 °F; 588 to 590 K) (decomposition) |
Miscible | |
Acidity (pKa) | 3.39 [3] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Phthalazine, also called benzo-orthodiazine or benzopyridazine, is a heterocyclic organic compound with the molecular formula C8H6N2. It is isomeric with other naphthyridines including quinoxaline, cinnoline and quinazoline.
Phthalazine can be obtained by the condensation of ω-tetrabromorthoxylene with hydrazine, or by the reduction of chlorphthalazine with phosphorus and hydroiodic acid. [4]
It possesses basic properties and forms addition products with alkyl iodides. [4]
Upon oxidation with alkaline potassium permanganate it yields pyridazine dicarboxylic acid. Zinc and hydrochloric acid decompose it with formation of orthoxylylene diamine. The keto-hydro derivative phthalazone (C8H6ON2), is obtained by condensing hydrazine with orthophthalaldehydoacid[ citation needed ]. On treatment with phosphorus oxychloride, it yields a chlorphthalazine, which with zinc and hydrochloric acid gives isoindole (C8H7N), and with tin and hydrochloric acid, phthalimidine (C8H7ON), the second nitrogen atom being eliminated as ammonia. [4]