1,3-Dimethyl-5-methyl­sulfonyl-1H-pyrazolo­[4,3-e][1,2,4]triazine

In the title compound, C7H9N5O2S, the pyrazolo­[4,3-e][1,2,4]triazine fused-ring system is essentially planar [maximum deviation = 0.0420 (3) Å]. In the crystal, mol­ecules related by twofold axes are linked into a mol­ecular net via inter­molecular C—H⋯O and C—H⋯N hydrogen bonds. π–π inter­actions are observed between the triazine and pyrazole rings of mol­ecules related by the the twofold axis and inversion symmetry with centroid–centroid distances of 3.778 (3) and 3.416 (3) Å, respectively

1,2-Bis[1-(3-methyl­sulfanyl-1,2,4-triazin-5-yl)ethyl­idene]diazane

The mol­ecule of the title compound, C12H14N8S2, has an N—N gauche conformation. The triazine rings are nearly coplanar with respect to the imide bonds [C—C—C—N torsion angles = −15.3 (3) and −15.8 (3)°] and they are twisted by 77.88 (7)°. The overall conformation of the mol­ecule is stabilized by intra­molecular C—H⋯N hydrogen bonding. The mol­ecular packing is influenced by π–π inter­actions of the triazine systems with a shortest centroid–centroid separation of 3.5242 (12) Å

1-(3-Chloro­phen­yl)-3-(1-p-tolyl­imidazolidin-2-yl­idene)urea

In the crystal structure of the title compound, C17H17ClN4O, the existence of only one 2-imino–oxo of the five possible N-amino–imino/O-keto–hydr­oxy tautomers is observed and the dihedral angle between the aromatic rings is 29.78 (11)°. The mol­ecular conformation is stabilized by intra­molecular C—H⋯N, N—H⋯O and C—H⋯O hydrogen bonds, in each case generating a six-membered ring. In the crystal structure, the glide-plane-related mol­ecules are linked into C(4) amide chains by inter­molecular N—H⋯O hydrogen bonds, and an inter­molecular C—H⋯O link also occurs

2-(3-Chloro-5,6-diphenyl-2,5-dihydro-1,2,4-triazin-5-yl)-2-methyl­propane­nitrile

The title compound, C19H17ClN4, was obtained from the reaction of 3-chloro-5,6-diphenyl-1,2,4-triazine with isobutyronitrile in the presence of lithium diisopropyl­amide as an unexpected product of covalent addition of isobutyronitrile carbanion to the C-5 atom of the 1,2,4-triazine ring. The 2,5-dihydro-1,2,4-triazine ring is essentially planar (r.m.s. deviation = 0.0059 Å) and the 5- and 6-phenyl substituents are inclined to its mean plane with dihedral angles of 89.97 (4) and 55.52 (5)°, respectively. Intra­molecular C—H⋯N inter­actions occur. In the crystal, mol­ecules related by a c-glide plane are linked into zigzag chains along [001] by N—H⋯N hydrogen bonds

5,6,7,8-Tetra­hydro­quinolin-8-one

In the quinoline fused-ring system of the title compound, C9H9NO, the pyridine ring is planar to within 0.011 (3) Å, while the partially saturated cyclo­hexene ring adopts a sofa conformation with an asymmetry parameter ΔC s(C6) = 1.5 (4)°. There are no classical hydrogen bonds in the crystal structure. Mol­ecules form mol­ecular layers parallel to (100) with a distance between the layers of a/2 = 3.468 Å

Synthesis of novel isothiazolopyridines and their in vitro evaluation against Mycobacterium and Propionibacterium acnes

AbstractIn this paper we describe synthesis, structures and some physicochemical properties of 20 isothiazolopyridines 8–13 substituted differently into an isothiazole ring as well as their in vitro antibacterial assays against Mycobacterium tuberculosis H37Rv, Mycobacterium fortuitum PCM 672 and Propionibacterium acnes PCM 2400. Compound 13a was found to be the most active derivative against M. tuberculosis H37Rv, demonstrating 100% growth inhibition of microorganisms in the primary screen (minimum inhibitory concentration [MIC] 6.25μg/mL). Nineteen of the prepared compounds were evaluated against M. fortuitum PCM 672 and P. acnes PCM 2400 and only compounds 9 and 12d exhibited excellent activity against individual strains of microorganisms with MIC90 <1μg/mL. The inhibitory action of the remaining isothiazolopyridines towards the tested strains of the microorganism was low, absent, or a non-linear correlation prohibited accurate determination of MIC values. Unexpectedly, seven of the remaining isothiazolopyridines tested against M. fortuitum and P. acnes stimulated growth of the microorganisms in the range 10–50% or even more (10b) under experimental conditions

5,6,7,8-Tetra­hydro­quinoline 1-oxide hemihydrate

In the title compound, C9H11NO·0.5H2O, the asymmetric unit contains two similar mol­ecules of 5,6,7,8-tetra­hydro­quinoline 1-oxide and one water mol­ecule. The water mol­ecule links the two O atoms of both independent N-oxides into dimers via O—H⋯O hydrogen bonds, forming a three-dimensional network along [101], which is additionally stabilized by weak C—H⋯O inter­molecular inter­actions. In each mol­ecule, the saturated six-membered rings exist in a conformation inter­mediate between a half-chair and sofa

2-(5,6-Diphenyl-1,2,4-triazin-3-yl)aniline

The title compound, C21H16N4, obtained under standard Suzuki cross-coupling conditions, is a model compound in the synthesis and biological activity evaluation of new aza-analogues of sildenafil containing a pyrazolo[4,3-e][1,2,4]triazine system. An N&amp;#8212;H...N intramolecular hydrogen bond involving the aminobenzene system and the 1,2,4-triazine moiety helps to establish a near coplanar orientation of the rings with a dihedral angle of 12.04&amp;#8197;(4)&amp;#176;, which is believed to be necessary for the biological activity of sildenafil analogues. The 1,2,4-triazine ring is slightly distorted from planarity [r.m.s deviation = 0.0299&amp;#8197;(11)&amp;#8197;&amp;#197;] and forms dihedral angles of 58.60&amp;#8197;(4) and 36.35&amp;#8197;(3)&amp;#176; with the pendant phenyl rings. The crystal packing features bifurcated N&amp;#8212;H...(N,N) hydrogen bonds linking screw-axis-related molecules into chains parallel to the [010] direction&amp;lt; and &amp;#960;&amp;#8211;&amp;#960; interactions, with a centroid&amp;#8211;centroid separation of 3.8722&amp;#8197;(7)&amp;#8197;&amp;#197; and a slippage of 1.412&amp;#8197;(3)&amp;#8197;&amp;#197;. The crystal studied was a nonmerohedral twin with a ratio of 0.707&amp;#8197;(2):0293&amp;#8197;(2)