4‐Hydro­xy‐1‐methyl‐2‐oxo‐N‐(4‐oxo‐2‐propyl‐3,4‐di­hydro­quinazolin‐3‐yl)‐1,2‐di­hydro­quinoline‐3‐carbox­amide

The two bicyclic fragments of the title compound, C₂₂H₂₀N₄O₄, are individually planar and are turned with respect to each other by 77.8 (2)°. The formation of intramolecular O—H?O and N—H?O hydrogen bonds causes considerable changes in the bond lengths within the amido­pyridine fragment.     

Supramolecular structures of 2‐cyano‐3‐di­methyl­amino‐N‐(4‐methyl­phenyl)­acryl­amide and 2‐cyano‐3‐di­methyl­amino‐N‐(2‐methoxy­phenyl)­acryl­amide

In the title compounds, C₁₃H₁₅N₃O, (I), and C₁₃H₁₅N₃O₂, (II), the dihedral angles between the planes of the phenyl ring and the amide group are 4.1 (1) and 20.7 (1)°, respectively. The mol­ecules adopt a fully extended conformation, aided by intramolecular interactions. The molecular structures of (I) and (II) display different crystal packing and hydrogen‐bonding networks.     

Antibacterial 4‐amino‐N‐(5‐methyl­isoxazol‐3‐yl)‐N‐[(4‐oxo‐2‐phenyl‐4H‐1‐benzopyran‐6‐yl)methyl]benzenesulfonamide

In the mol­ecule of the title compound, C₂₆H₂₁N₃O₅S, a new type of sulfonamide derivative with potential antibacterial activity, the flavone moiety is almost planar. The isoxazole and amino­phenyl rings are also planar and make dihedral angles of 77.0 (2) and 81.4 (1)°, respectively, with the best plane of the flavone ring system. The crystal structure is stabilized by intra‐ and inter­molecular hydrogen bonds.     

O‐(2‐tert‐Butyl‐6‐di­methyl­thio­carbamoyl‐4‐methylphenyl) N,N‐di­methyl­thiocarbamate di­chloro­methane solvate

In the title compound, C₁₇H₂₆N₂OS₂·CH₂Cl₂, the C=S distances are 1.650 (4) and 1.679 (3) Å, and the torsion angle between the planes of the thio­carbamate and carbono­thio­yl fragments is 54.4 (2)°. The steric and electronic effects that these substituents exert on one another determine the observed anti configuration with respect to the phenyl C atoms to which they are attached.     

4‐Methyl‐2‐[N‐(3,4‐methyl­ene­dioxy­benzyl­idene)hydrazino]­thia­zole and its reduction product, 4‐methyl‐2‐[N‐(3,4‐methyl­ene­dioxybenzyl­idene)hydrazono]‐4,5‐di­hydro­thia­zole

The crystal structures of 4‐methyl‐2‐[N‐(3,4‐methyl­ene­dioxybenzyl­idene)hydrazino]­thia­zole, C₁₂H₁₁N₃O₂S, and its reduction product 4‐methyl‐2‐[N‐(3,4‐methyl­ene­dioxybenzyl­idene)hydrazono]‐4,5‐di­hydro­thia­zole, C₁₂H₁₃N₃O₂S, have been determined and compared. In the reduction product, the tautomer observed bears an H atom on the exocyclic N atom. Both compounds form hydrogen‐bonded dimers over centers of inversion.     

3‐(Ethoxy­carbonyl­di­hydroxy­methyl)‐2‐oxo‐1,2‐di­hydro­quinox­aline

The crystal structure of the title compound, ethyl 2,2‐di­­hy­droxy‐2‐(3‐oxo‐3,4‐di­hydro­quinoxalin‐2‐yl)­acetate, C₁₂H₁₂N₂O₅, indicates a short intramolecular contact between the N1 atom and a hydroxyl group [2.772 (4) Å]. Two intermolecular hydrogen bonds participate in the molecular packing.     

4‐(4‐Fluoro‐3‐phenoxy­phen­yl)‐6‐(4‐fluoro­phen­yl)‐2‐oxo‐1,2‐dihydro­pyridine‐3‐carbonitrile and the 6‐(4‐methyl­phen­yl)‐ analogue

The crystal structures of the title compounds, viz. C₂₄H₁₄F₂N₂O₂, (I), and C₂₅H₁₇FN₂O₂, (II), respectively, have been determined in order to unravel the role of an ordered F atom in generating stable supra­molecular assemblies. On changing the substitution from fluorine to a methyl group, C—H⋯F inter­actions are replaced by C—H⋯π inter­actions, revealing the importance of such weak inter­actions when present alongside N—H⋯O and C—H⋯O hydrogen bonds. The dihedral angle between the planes of the 4‐fluoro­phenyl ring and the pyridine ring is 26.8 (1)° in (I), while that between the planes of the 4‐methyl­phenyl and pyridine rings is 29.5 (1)° in (II).     

The diprotonated 2,2‐(propane‐1,3‐di­yl)bis­(1,1,3,3‐tetra­methyl­guanidinium) cation: packing and conformational changes

Subject to packing with different anions, the title cation undergoes various conformational changes with significantly different N—C—C—C torsion angles, as well as different angles between the NCN₂ guanidine planes. The 2,2‐(propane‐1,3‐di­yl)bis­(1,1,3,3‐tetra­methyl­guanidinium) salts reported here, viz. the dibromide, C₁₃H₃₂N₆²⁺·2Br⁻, the tetra­phenyl­borate chloride, C₁₃H₃₂N₆²⁺·C₂₄H₂₀B⁻·Cl⁻, the tetra­chloro­mercurate, (C₁₃H₃₂N₆)[HgCl₄], and the bis­(trifluoro­methanesulfonate), C₁₃H₃₂N₆²⁺·2CF₃SO₃⁻, are dominated by strong inter­molecular N—H⋯X hydrogen bonds, which form different packing patterns.     

1,3‐Bis(4‐methyl­phen­yl)triazene, 1‐(4‐chloro­phen­yl)‐3‐(4‐fluoro­phen­yl)triazene and 1‐(4‐fluoro­phen­yl)‐3‐(4‐methyl­phen­yl)triazene

The title 4,4′‐disubstituted diphen­yl‐1,3‐triazines, C₁₄H₁₅N₃, (I), C₁₂H₉ClFN₃, (II), and C₁₃H₁₂FN₃, (III), each contain a triazene group (–N=N—NH–) having an extended conformation. The dihedral angles between the two benzene rings in (I), (II) and (III) are 4.3, 3.4 and 6.5°, respectively. The mol­ecules are almost entirely planar, with maximum deviations from the mean planes of 0.1087 (2), −0.1072 (7) and 0.1401 (3) Å, respectively. In each compound, the molecules are linked by N—H⋯N hydrogen bonds to form chains and pack similarly in the crystal structures.     

3‐(4‐Chloro­benzoyl)‐7‐(N,N‐di­methyl­amino)‐1‐phenyl­indolizine and 3‐(2,4‐di­chloro­benzoyl)‐7‐(N,N‐di­methyl­amino)‐1‐phenyl­indolizine

In both of the title compounds, C₂₃H₁₉ClN₂O, (I), and C₂₃H₁₈Cl₂N₂O, (II), the molecular packing is influenced by weak intermolecular C—H⋯O and C—H⋯π interactions, but despite the chemical similarity of the compounds, the packing in (II) is entirely different from that observed in (I).     

(+)‐(2R,3S)‐3‐Bromo‐2‐chloro‐N,N‐diiso­propyl‐3‐phenyl­propan­amide and (+)‐(2R,3S)‐3‐bromo‐2‐chloro‐N‐(4‐nitro­phenyl)‐3‐phenyl­propan­amide

The stereochemistries at positions 2 and 3 of the title compounds, C₁₅H₂₁BrClNO, (I), and C₁₅H₁₂BrClN₂O₃, (II), have been confirmed by X‐ray structural analysis. The halogen atoms adopt an antiperiplanar arrangement in each case.     

N,N‐Di­methyl­anilinium 3‐cyano‐4‐(di­cyano­methyl­ene)‐5‐oxo‐4,5‐di­hydro‐1H‐pyrrol‐2‐olate

In the title compound, C₈H₁₂N⁺·C₈HN₄O₂⁻, the anion and cation lie on a crystallographic mirror plane and form planar ribbons via N—H⋯O [N⋯O = 2.933 (4) Å, H⋯O = 2.01 Å and N—H⋯O = 170°] and N—H⋯N [N⋯N = 3.016 (5) Å, H⋯N = 2.15 Å and N—H⋯N = 169°] hydrogen bonds. The ribbons are further linked via weak C—H⋯O and C—H⋯N hydrogen bonds. In adjacent planes, anions lie opposite cations; π–π interactions (separation a/2 = 3.520 Å) exist between the anions and the cations, and stacks are formed, running along the a axis. The cations are disordered over two interpenetrating sites, with occupancies of 0.833 (5) and 0.167 (5).     

N‐[(R)‐1‐(2‐Hydr­oxy‐5‐methyl­phen­yl)­eth­yl]‐N‐[(R)‐1‐(2‐meth­oxy‐5‐methyl­phen­yl)‐2‐phenyl­eth­yl]aminium chloride

The title compound, C₂₅H₃₀NO₂⁺·Cl⁻, has been synthesized, and the crystal structure shows that it is mainly stabilized through inter­molecular N—H·Cl and O—H·Cl and intra­molecular N—H·O hydrogen bonds. The absolute configuration of the new stereogenic center (the C atom adjacent to the N atom on the phenol side) was determined to have an R configuration.     

N‐(2‐Amino­benz­yl)‐N,N‐bis­(quinolin‐2‐ylmeth­yl)amine

The title new diquinaldine derivative, C₂₇H₂₄N₄, forms mol­ecular assemblies organized by inter­molecular quinoline π–π stacking [3.356 (3) and 3.440 (3) Å] and both inter‐ and intra­molecular N—H⋯N hydrogen bonds [3.039 (3)–3.104 (3) Å and 129 (2)–172 (2)°]. The combination of such inter­actions provides readily definable contacts that propagate along each crystallographic axis.     

N‐Methyl­pyridinium 3‐cyano‐4‐(di­cyano­methyl­ene)‐5‐oxo‐4,5‐di­hydro‐1H‐pyrrol‐2‐olate

The crystal structure of the title compound, C₆H₈N⁺·C₈HN₄O₂⁻, is characterized by three independent ion pairs (A, B and C) in the asymmetric unit. Each ion pair consists of an anion and a cation, and the three ion pairs have similar geometric parameters. All the anions are arranged as dianion dimers via two N—H⋯O hydrogen bonds and the dimers form one‐dimensional columns parallel to the b axis as a result of π–π interactions. The cations are also stacked, in two different ways: one type of stacking consists of alternating A and B cations, while the other type consists of C cations only. Each dianion dimer stack is surrounded by eight stacks of cations and is not connected directly to other dianion stacks.     

N,N′‐Bis­(dipiperidin‐1‐yl­methyl­ene)propane‐1,3‐di­amine and N,N′‐bis(1,3‐di­methyl­per­hydro­pyrimidin‐2‐yl­idene)­propane‐1,3‐di­amine

The molecular structures of the title compounds, C₂₅H₄₆N₆ and C₁₅H₃₀N₆, respectively, show the two guanidyl moieties each connected by propyl bridges. The different substitution pattern of the guanidyl groups has no influence on the distinct localization of their C=N double bonds. Both compounds exhibit approximate twofold symmetry and the crystal packing shows no prominent hydrogen‐bonding interactions.     

2‐Benzoyl‐N‐phenyl‐2‐(1,2,4‐triazol‐1‐yl)­thio­acet­amide and 2‐(4‐methoxy­benzoyl)‐N‐phenyl‐2‐(1,2,4‐triazol‐1‐yl)­thio­acet­amide

In the two title compounds, C₁₇H₁₄N₄OS, (I), and C₁₈H₁₆N₄O₂S, (II), the dihedral angles between the planes of the triazole and N‐phenyl rings and the plane of five of the atoms that link these two rings are 63.5 (8) and 73.2 (6)° for (I), and 65.1 (1) and 72.1 (3)° for (II), respectively. There are some inter‐ and intramolecular interactions in the crystal structure.     

1‐[(4‐Chloro­benzoyl)­methyl]‐4‐(N,N‐di­methyl­amino)­pyridinium bromide sesquihydrate and 1‐[(4‐bromo­benzoyl)­methyl]‐4‐(N,N‐di­methyl­amino)­pyridinium bromide sesquihydrate

The title compounds, C₁₅H₁₆ClN₂O⁺·Br⁻·1.5H₂O and C₁₅H₁₆BrN₂O⁺·Br⁻·1.5H₂O, are isomorphous. The benzene ring is oriented nearly normal to the pyridine ring in both compounds. The molecular packing is mainly influenced by intermolecular O—H⋯O and O—H⋯Br interactions, as well as weak intramolecular C—H⋯O interactions. The H₂OBr⁻ units form an extended water–bromide chain, with a bridging water mol­ecule on a twofold axis.     

Diethyl 1‐(4‐fluoro­phenyl)‐3‐(2‐furyl)‐5‐oxopyrrolidine‐2,2‐di­carboxyl­ate and diethyl 1‐(3,4‐di­chloro­phenyl)‐3‐(2‐furyl)‐5‐oxopyrrolidine‐2,2‐di­carboxyl­ate

The title compounds, C₂₀H₂₀FNO₆ and C₂₀H₁₉Cl₂NO₆, respectively, may exhibit bioactivity. In these compounds, the pyrrolidine ring adopts a conformation intermediate between envelope and half‐chair. Only one of the two ethoxy­carbonyl side chains is nearly planar. Centrosymmetric pairs are formed, and the crystal structure is stabilized by weak C—H⋯O hydrogen bonds and van der Waals interactions.     

2‐(4‐Acetyl‐3,5‐di­hydroxy‐2‐methyl­phenoxy)‐4,6‐di­methoxy‐3‐methyl­benzoic acid

In the title compound, C₁₉H₂₀O₈, the benzene rings are nearly perpendicular to each other [dihedral angle 80.2 (2)°]. The carboxy group is twisted out while both the methoxy and acetyl groups are almost coplanar with their attached benzene rings. The hydroxy group is involved in an intramolecular O—H?O hydrogen bond with the acetyl O atom and the compound is connected through an intermolecular O—H?O contact to form a dimer. The crystal structure is stabilized by intermolecular O—H?O hydrogen bonds.