In the title mol-ecule, C(22)H(16)N(2)O, the tolyl and benzoyl rings make dihedral angles 50.2 (5) and 56.4 (5)°, respectively, with the phthalazine ring system while the dihedral angle between the tolyl and benzoyl rings is 0.70 (4)°. The crystal structure is stabilized by inter-molecular C-H⋯O and C-H⋯N hydrogen bonds, as well as weak C-H⋯π inter-actions.

The elaboration of the first organophosphorus-catalyzed diaza-Wittig reaction is reported. This catalytic reaction is applied to the synthesis of substituted pyridazine and phthalazine derivatives bearing electron-withdrawing groups with good to excellent yields from substrates containing a diazo functionality as the starting material and a phospholene oxide as the catalyst.

In this investigation a simple synthetic method for the synthesis of trifluoromethyl-1H-benzo[e][1,2,4]triazolo[1,2-a][1,2,4]triazine-1,3(2H)-diones and (trifluoromethyl)benzo [5,6][1,2,4]triazino[1,2-b]phthalazine-8,13-diones has been developed using urazole or phthalazine and aceteimidoyl chloride derivatives at room temperature under ultrasound irradiations. In the comparison to the conventi...

The title compound, C21H16N2O3, consists of an indazolone moiety, bearing a phenyl group, fused to a phthalazine ring system (r.m.s. deviation = 0.018 Å). The phenyl ring is almost normal to the mean plane of the five-membered ring of the indazolone moiety, making a dihedral angle of 89.64 (7)°. The six-membered ring of the indazolone moiety has an envelope conformation, with the central methyl...

Quinazoline, quinoxaline and phthalazine are nitrogen containing heterocyclic aromatic molecules which belong to the class diazanaphthalenes. These isomers have low-lying nπ* and naphthalene-like ππ* states that interact via spin-orbit coupling. In this contribution, we study their structure and electronic states by means of a coupled-cluster method. The computed properties are compared to thos...

Ab initio calculations at the level of CASPT2 with Dunning's correlation consistent cc-pVXZ (X=D, T, Q) basis sets have been carried out for pyrimidine, quinoxaline, phthalazine, and their substituted compounds to find candidates that show a change in the direction of the electric dipole moment for the S(0)-->S(1) transition. The present calculations reveal that 6,7-difluorophthalazine and 6,7-...

In the title compound, C22H18N2O4, the three fused rings of the pyrazolo-phthalazine moiety are coplanar (r.m.s. deviation = 0.027 Å). The cyclo-hexene ring fused to the pyrazolidine ring, so forming the indazolophthalazine unit, has a half-chair conformation. The benzene ring is almost normal to the mean plane of the pyrazolo-phthalazine moiety, with a dihedral angle of 87.21 (6)° between thei...

In the title mol-ecule, C(26)H(26)N(2)O, the phenyl and phen-oxy rings form dihedral angles of 54.66 (7) and 84.83 (6)°, respectively, with the phthalazine mean plane. The crystal packing exhibits weak C-H⋯π inter-actions.

In the crystal structure of the title compound, C(17)H(10)N(4)O(5), the mol-ecules lie on twofold axes (through the ketone bridge C and O atoms). The dihedral angle between the two phthalazine rings is 52.25 (1)°. In the crystal, inter-molecular N-H⋯O and O-H⋯O inter-actions link the mol-ecules.