Copper(I) and nickel(0) complexes catalyze the formal [4 + 2] cycloaddition reactions of 1,2-diazines and siloxyalkynes, a reaction hitherto best catalyzed by silver salts. These catalysts based on earth abundant metals are not only competent, but the copper catalyst, in particular, promotes cycloadditions of pyrido[2,3-d]pyridazine and pyrido[3,4-d]pyridazine, enabling a new synthesis of quino...

The title compound, C(15)H(13)F(3)N(2)O, contains one benzene ring, one cyclo-hexane ring and a pyridazine ring. The dihedral angle formed by the pyridazine ring with the benzene ring is 61.5 (2)°. The crystal structure is stabilized by two inter-molecular hydrogen bonds (N-H⋯O and C-H⋯F). The cyclohexane ring adopts a screw-boat conformation. The CF(3) group is disordered over two positions; t...

The vascular endothelial growth factor (VEGF) signaling pathway has been implicated in tumor angiogenesis, and inhibition of the VEGF pathway is considered an efficacious method for treating cancer. Herein, we describe synthetic studies of imidazo[1,2-b]pyridazine derivatives as VEGF receptor 2 (VEGFR2) kinase inhibitors. The imidazo[1,2-b]pyridazine scaffold was designed and synthesized as a h...

In the title compound, [Cu(C5H3N2O2)2(H2O)2], the Cu(II) ion, located on an inversion center, exhibits an octa-hedral coordination geometry. The equatorial plane is defined by two trans-related N,O-bidentate pyridazine-3-carboxyl-ate ligands and the axial positions are occupied by two water mol-ecules. In the crystal, mol-ecules are connected by O-H⋯O hydrogen bonds between the water mol-ecules...

Vibrational structure of the pyridazine cation in the ground state has been revealed by a vacuum-ultraviolet mass-analyzed threshold ionization (VUV-MATI) spectroscopy. The adiabatic ionization energy is precisely measured to be 70241 +/- 6 cm(-1) (8.7088 +/- 0.0007 eV). The origin is very weakly observed, while a long progression of the nu9(+) (a1) band of which the fundamental vibrational fre...

Compounds that interact with DNA or RNA generally act as inhibitors of enzymes that unwind DNA or RNA. In the present study we describe the synthesis and properties of some nucleoside analogues that interact with double-stranded DNA but that, in contrast, facilitate the unwinding reaction mediated by West Nile (WN) virus nucleoside triphosphatase (NTPase)/helicase. The nucleoside analogues desc...

By the reaction of various amines with 3-chloropyridazines,several minaprine analogues were prepared.Most of them exhibited significant antidepressant activity.Compound 2a antagonizes reserpine action and neuroleptic-induced catalepsy in a dose-dependent manner. Keywords-disubstituted benzylidene pyridazine;3-amino pyridazine derivative,minaprine analogue;antidepressant activity Recently,it was...

Reaction of an excess nickel(II) thio-cyanate with pyridazine leads to single crystals of the title compound, [Ni(3)(NCS)(6)(N(2)C(4)H(4))(4)(CH(3)OH)(2)]·4CH(3)OH. The crystal structure consists of trimeric discrete complexes, in which two Ni(II) cations are coordinated by two terminal and one μ-1,1 bridging thio-cyanato anions, one methanol mol-ecule and two bridging pyridazine ligands, where...

Substituted pyrroles may be synthesized from selected 1,2-pyridazines through a reductive ring contraction involving the addition of four electrons and four protons. Our density functional theory computations of this reaction mechanism show that the first reduction event must be preceded by the uptake of one proton by 1,2-pyridazine and that the reaction proceeds through a 2e(-)/3H(+)-bearing i...