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.

During the course of our research efforts to understand the kinetics of human aldehyde oxidase as a xenobiotic-clearing enzyme, we investigated the effect of eight different inhibitors on the oxidation of the probe substrate phthalazine. Saturation kinetic parameters for phthalazine oxidation in human liver cytosol were found to be the following: K(m) = 8.0 ± 0.4 μM and V(max) = 4.3 ± 0.1 nmol ...

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-...