In the title mol-ecular salt [systematic name: 2-methyl-pyridinium 5-(2,4-dinitro-phen-yl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetra-hydro-pyrimidin-4-olate], C(6)H(8)N(+)·C(12)H(9)N(4)O(7) (-), the cation and anion are linked a through strong N-H⋯O hydrogen bond. In the crystal, C-H⋯O inter-actions link the ions, generating a chain along [010].

1, 8-Dioxo-octahydroxanthene derivatives have efficiently been synthesized from dimedone and aromatic aldehydes using [Fe(III)(salen)Cl] complex as an efficient and homogeneous catalyst in molten tetrabutyl ammonium bromide. This methodology offers several advantages, such as good yields, short reaction times, simple procedure, and mild conditions.

Polyethyleneglycol bound sulfonic acid (PEG-OSO₃H), a chlorosulphonic acid-modified polyethylene glycol was successfully used as an efficient and eco-friendly polymeric catalyst in the synthesis of 14-aryl/heteroaryl-14H-dibenzo[a,j]xanthenes obtained from the reaction of 2-naphthol and carbonyl compounds under solvent-free conditions with short reaction times and excellent yields. The biologic...

The biosynthesis of nitric oxide (NO) is catalyzed by homodimeric NO synthases (NOS). For unknown reasons, all NOS co-purify with substoichiometric amounts of (6R)-5,6,7,8-tetrahydrobiopterin (H(4)Bip) and require additional H(4)Bip for maximal activity. We examined the effects of H(4)Bip and pterin-derived inhibitors (anti-pterins) on purified neuronal NOS-I quaternary structure and H(4)Bip co...

Some novel 2,3-dioxo-5-(substituted)-arylpyrroles have been synthesized. Among these, pyrrolidine compound 1b was converted to 2,3-dioxo-5-aryl pyrrolidine 2b. Finally a set of hydrazone derivatives was obtained from the reaction of 2b with various hydrazine salts. The structures of all the new synthesized compounds were confirmed by elemental analyses, IR and 1H-NMR spectra.

In the title compound, C22H21N3O5, the β-lactam (azetidin-2-one) ring is nearly planar [maximum deviation = 0.010 (1) Å] and makes dihedral angles of 69.22 (5), 55.32 (5) and 89.42 (4)° with the least-squares planes formed by the four C atoms of the morpholine ring, which adopts a chair conformation, the benzene ring and the xanthene ring system, respectively. In the crystal, C-H⋯O hydrogen-bon...

The β-lactam (azetidin-2-one) ring of the title compound, C28H27N3O5, is nearly planar [maximum deviation = 0.010 (1) Å] and makes dihedral angles of 75.77 (5), 52.78 (9) and 88.72 (5)°, respectively, with the benzene ring, the least-squares plane formed by the four C atoms of the morpholine ring, which adopts a chair conformation, and the xanthene ring system. In the crystal, C-H⋯O hydrogen-bo...

In the xanthene ring system of the title compound, C(23)H(25)BrO(4), the 4H-pyran ring is almost planar [maximum deviation = 0.040 (3) Å] and the cyclo-hexene ring adopts a sofa conformation. The cyclo-hexene ring attached to the xanthene system is puckered [Q(T) = 0.427 (3) Å, θ = 55.0 (4) ° and ϕ = 164.4 (6) °]. In the crystal, mol-ecules are linked to each other by O-H⋯O and C-H⋯O hydrogen b...

In the title compound, C(23)H(26)O(3), the three six-membered rings of the xanthene system are non-planar, having total puckering amplitudes, Q(T), of 0.443 (2), 0.202 (2) and 0.449 (2) Å. The central ring adopts a boat conformation and the outer rings adopt sofa conformations. The crystal structure is stabilized by van der Waals inter-actions.