The vaporization enthalpies and liquid vapor pressures of quinoxaline, quinazoline, phthalazine, benzo[c]cinnoline, 1,10-phenanthroline, phenazine, and triphenylamine are measured by correlation-gas chromatography and compared to values calculated from available literature vaporization, sublimation, and fusion enthalpy data. Good agreement with the literature is observed for all compounds excep...

Density functional theory calculations were used to examine the role of the urease model complex [Ni2(bdptz)(micro-OH)(micro-H2O)(H2O)2](OTs)3(bdptz=1,4-bis(2,2'-dipyridylmethyl)-phthalazine; OTs=tosylate) in the degradation of urea. An elimination mechanism that converts urea to ammonium cyanate was investigated in detail. The lowest energy pathway involves urea coordination through the oxygen...

The sodium salts of some hetaryls of the quinoxalin-2-ones 2-4, phthalazine-1,4-dione 5, phthalazin-1-one 6, and pyridazin-6-ones 7 and 8 were alkylated with (+/-) 2,3-O-isopropylidene-1-O-(4-toluenesulfonyl)glycerol (1) to give the respective tetraseco-nucleosides 9-15. Their deisopropylidenation with 70% acetic acid in water gave the corresponding 2,3-dihydroxyprop-1-yl hetaryls 16-22. Compou...

We report an air-stable bisboron complex as an efficient catalyst for the inverse electron-demand Diels-Alder (IEDDA) reaction of 1,2-diazine as well as 1,2,4,5-tetrazine. Its stability towards air and moisture was demonstrated by NMR studies enabling its application in organic transformations without glovebox. A one-pot procedure for its synthesis was developed starting from 1,2-bis(trimethyls...

In the crystal structure of the title compound, C(10)H(8)N(4)·H(2)O, the organic mol-ecules are approximately planar [maximum deviation from the least-squares plane = 0.041 (2) Å]. Two mol-ecules are connected by two water mol-ecules via O-H⋯N hydrogen bonding into dimers, which are located around centres of inversion. In the crystal, mol-ecules are stacked in the a-axis direction, with mean di...

BACKGROUND QUAN-0808 (6-(4-chlorophenoxy)-tetrazolo[5,1-a]phthalazine), a new phthalazine tetrazole derivative, was evaluated for the anti-inflammatory and analgesic effects. METHODS Xylene-induced ear edema, carrageenan (Carr)-induced paw edema, and acetic acid-induced capillary permeability hyperactivity in mice were used to assess the anti-inflammatory effect; acetic acid-induced writhing ...

Melamine trisulfonic acid (MTSA) as an efficient heterogeneous catalyst has been used for the one-pot preparation of triazolo[1,2-a]indazole-1,3,8-trione and 2H-indazolo[2,1-b]phthalazine-1,6,11-trione derivatives by the three-component condensation reaction of urazoles or phthalhydrazide, dimedone or 1,3-cyclohexanedione, and aldehydes under solvent-free conditions in good to excellent yields ...