Three methoxy‐substituted diethyl 4‐­phenyl‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate compounds

Diethyl 4‐(2,5‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₁H₂₇NO₆, (I), diethyl 4‐(3,4‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₁H₂₇NO₆, (II), and diethyl 2,6‐di­methyl‐4‐(3,4,5‐tri­methoxy­phenyl)‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₂H₂₉NO₇, (III), crystallize with hydrogen‐bonding networks involving the H atom bonded to the N atom of the 1,4‐di­hydro­pyridine ring and carbonyl O atoms in (I) and (II). Unusually, (III) shows O atoms of methoxy groups serving as hydrogen‐bond acceptors.     

2‐Ethyl­phenyl acridine‐9‐carboxyl­ate and 2,5‐dimethyl­phenyl acridine‐9‐carboxyl­ate

The title compounds, 2‐ethyl­phenyl acridine‐9‐carboxyl­ate, C₂₂H₁₇NO₂, (I), and 2,5‐dimethyl­phenyl acridine‐9‐carboxyl­ate, C₂₂H₁₇NO₂, (II), form triclinic and monoclinic crystals, respectively. Related by a centre of symmetry, adjacent molecules of (I) are linked in the lattice via a network of C—H·π and non‐specific dispersive interactions. As a result, acridine moieties and independent phenyl moieties of (I) are parallel in the lattice. The molecules of (II), arranged in a `head‐to‐tail' manner and related by a centre of symmetry, form pairs stabilized via C—H·π interactions. These are linked in the crystal via dispersive interactions. Acridine and independent phenyl moieties lie parallel within the pairs, while adjacent pairs are perpendicular, forming a herring‐bone pattern.     

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.     

Di­propyl 3,6‐di­phenyl‐1,2‐di­hydro‐1,2,4,5‐tetrazine‐1,2‐di­carboxyl­ate

The title compound, C₂₂H₂₄N₄O₄, was prepared from propyl chloro­formate and 3,6‐di­phenyl‐1,2‐di­hydro‐s‐tetrazine. This reaction yields the title compound rather than di­propyl 3,6‐di­phenyl‐1,4‐di­hydro‐s‐tetrazine‐1,4‐di­carboxyl­ate. The 2,3‐di­aza­buta­diene group in the central six‐membered ring is not planar; the C=N double‐bond length is 1.285 (2) Å, and the average N—N single‐bond length is 1.401 (3) Å, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie 0.3268 (17) Å from the plane of the ring. The mol­ecule has twofold crystallographic symmetry.     

Diethyl 9,10‐di­hydro‐9,10‐ethano­anthracene‐11,12‐trans‐di­carboxyl­ate

The title compound, C₂₂H₂₂O₄, is the product of the Diels–Alder reaction of anthracene with fumaric acid diethyl ester. The molecular C₂ symmetry is nearly fulfilled in the crystal. Only the terminal torsion angles about the O—CH₂ groups show significant differences.     

Diethyl 4‐(2,5‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate,conformational change with solvent of crystallization

The title compound, C₂₁H₂₇NO₆, has been crystallized from ethanol containing nitro­benzene and shows the phenyl ring, B, in an ap conformation. This structure may be compared with that of the mol­ecule crystallized from ethanol alone, in which the B ring is seen in an sp conformation. The isolation of this rotamer has implications for the understanding of the docking of calcium beta‐blocking di­hydro­pyridine mol­ecules with their receptor site.     

Sodium pyridine‐3‐carboxyl­ate

The title compound, also known as sodium nicotinate, Na⁺·C₆H₄NO₂⁻, consists of two unique Na atoms coordinated to two unique pyridine‐3‐­carboxyl­ate ligands through the N atoms and carboxylate groups. One Na atom and one pyridine‐3‐­carboxyl­ate ligand lie on a twofold axis. Extensive Na coordination results in a three‐dimensional array comprising infinite NaO₂CR chains linked by intrachain Na—N bonds.     

Ferrocene compounds. XXXVIII. Di­methyl ferrocene‐1,1′‐di­carboxyl­ate

In the title compound, [Fe(C₇H₇O₂)₂], the cyclo­penta­dienyl rings and the two attached methoxy­carbonyl groups, in an anti arrangement, form an extended π‐conjugated system. The Fe—C distances range from 2.035 (3) to 2.061 (3) Å and the average value of the C—C bond lengths in the two cyclo­penta­dienyl rings is 1.419 (5) Å. The rings are almost parallel to one another [1.0 (2)°] and are mutually twisted from an eclipsed conformation by only 1.8 (3)° (average value). The methoxy­carbonyl groups are twisted out of the plane of the cyclo­penta­dienyl rings by 6.5 (4) and 15.7 (4)°, respectively. The mol­ecules are joined into dimers by intermolecular C—H⃛O hydrogen bonds that form ten‐membered rings. The same types of hydrogen bonds form eight‐membered rings and infinite chains along the b axis.     

The stable inner salt 2,2‐dimorpholino‐2‐ethyl­ium‐1‐di­thio­ate

The title compound, C₁₀H₁₆N₂O₂S₂, is considered to maintain an inner‐salt structure in the crystal, where the planes of the carbenium and the thio­carboxyl­ate moieties are nearly perpendicular to each other [77 (2)°], and the backbone C—C bond length [N₂C—CS₂ 1.510 (2) Å] is significantly shorter than a normal C—C single‐bond length.     

2,4‐Di­nitro­phenyl­hydrazones of 2,4‐di­hydroxy­benz­aldehyde, 2,4‐di­hydroxy­aceto­phenone and 2,4‐di­hydroxy­benzo­phenone

In 2,4‐di­hydroxy­benz­aldehyde 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­form­amide solvate {or 4‐[(2,4‐di­nitro­phenyl)­hydrazono­methyl]­benzene‐1,3‐diol N,N‐di­methyl­form­amide solvate}, C₁₃H₁₀N₄O₆·C₃H₇NO, (X), 2,4‐di­hydroxy­aceto­phenone 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­form­am­ide solvate (or 4‐{1‐[(2,4‐di­nitro­phenyl)hydrazono]ethyl}benzene‐1,3‐diol N,N‐di­methyl­form­amide solvate), C₁₄H₁₂N₄O₆·C₃H₇NO, (XI), and 2,4‐di­hydroxy­benzo­phenone 2,4‐di­nitro­phenyl­hydrazone N,N‐di­methyl­acet­amide solvate (or 4‐­{[(2,4‐di­nitro­phenyl)hydrazono]phenyl­methyl}benzene‐1,3‐diol N,N‐di­methyl­acet­amide solvate), C₁₉H₁₄N₄O₆·C₄H₉NO, (XII), the molecules all lack a center of symmetry, crystallize in centrosymmetric space groups and have been observed to exhibit non‐linear optical activity. In each case, the hydrazone skeleton is fairly planar, facilitated by the presence of two intramolecular hydrogen bonds and some partial N—N double‐bond character. Each molecule is hydrogen bonded to one solvent mol­ecule.     

Two biologically active thio­phene‐3‐carbox­amide derivatives

The two title compounds, 2‐({(1Z)‐[4‐(di­methyl­amino)phenyl]methylene}amino)‐4,5‐dimethyl‐N‐(2‐methylphenyl)thiophene‐3‐carboxamide, C₂₃H₂₅N₃OS, (I), and 2‐({(1E)‐[4‐(dimethylamino)phenyl]methylene}amino)‐N‐(4‐methylphenyl)‐4,5,6,7‐tetrahydro‐1‐benzothiophene‐3‐carboxamide,C₂₅H₂₇N₃OS, (II), show antibacterial and antifungal activities. The asymmetric unit of (II) contains two crystallographically independent mol­ecules. The o‐toluidine ring in (I) lies gauche with respect to the thio­phene ring. In (II), the p‐toluidine ring is coplanar with the thio­phene ring in one mol­ecule, but is tilted from it in the other mol­ecule. Neither structure exhibits any significant intermolecular interactions, but in both, an intramolecular N—H⋯N hydrogen bond forms a pseudo‐six‐membered ring, thus locking the molecular conformation and removing conformational flexibility.     

Methyl 3‐para‐anisyl‐4‐(2‐hydroxy­benzoyl)­isoxazole‐5‐carboxyl­ate

The title compound, C₁₉H₁₅NO₆, contains a planar isoxazole ring. An intramolecular hydrogen bond is formed between the OH group attached to a phenyl ring and a carbonyl O atom.     

Two biologically active thio­phene‐3‐carbox­amide derivatives

The compounds 2‐{[(E)‐(4‐methoxy­phenyl)­methyl­ene]­amino}‐N‐(3‐methyl­phenyl)‐4,5,6,7‐tetra­hydro‐1‐benzo­thio­ph­ene‐3‐carbox­amide, C₂₄H₂₄N₂O₂S, (I), and N‐(4‐meth­yl­phenyl)‐2‐{[(E)‐(4‐methyl­phenyl)­methyl­ene]­amino}‐4,5,6,7‐tetra­hydro‐1‐benzo­thio­phene‐3‐carbox­amide, C₂₄H₂₄N₂OS, (II), show antibacterial and antifungal activities. The m‐toluidine ring in (I) and the p‐toluidine ring in (II) are coplanar with their respective thio­phene rings. In (I), an intermolecular C—H⋯O hydrogen bond is present, whereas (II) does not exhibit any significant intermolecular interactions. However, in both compounds, an intramolecular N—H⋯N hydrogen bond forms a pseudo‐six‐membered ring, thus locking the molecular conformation and eliminating conformational flexibility.     

3,5‐Pyrazole­di­carboxyl­ic acid monohydrate

In the title compound, C₅H₄N₂O₄·H₂O, the 3,5‐pyrazoledicarboxylic acid (H₃pdc) molecules are joined into one‐dimensional chains by O—H?O and N—H?O hydrogen bonds, with distances of 2.671 (2) and 2.776 (2) Å, respectively. The one‐dimensional chains form a three‐dimensional structure via O—H?OW and OW—HW?N hydrogen bonds, with distances of 2.597 (3) and 2.780 (3) Å, respectively. In addition to the potential for forming open‐channel frameworks, access to the six coordination atoms of H₃pdc can be directly controlled by varying the pH of the reaction environment, allowing further control over the design and synthesis of novel coordination polymers using various metal centers.     

Sodium di­hydrogen tris­(cyclo­propane­carboxyl­ate)

The title acid salt, Na⁺·C₄H₅O₂^?·2C₄H₆O₂, contains finite anions in which two cyclo­propanoic acid mol­ecules are hydrogen bonded to a cyclo­propanoate residue. Each such anion interacts with four different Na⁺ cations.     

C—H⋯O interactions in diethyl 5,5′,6,6′‐tetra­methyl­bi­phenyl‐2,2′‐di­carboxyl­ate at 193 K

The title compound, C₂₂H₂₆O₄, crystallized in the centrosymmetric space group P with one mol­ecule as the asymmetric unit. Three leading intermolecular C—H?O interactions have H?O distances of 2.71, 2.73 (2) and 2.71 (2) Å and C—H?O angles of 167, 137.0 (15) and 163.1 (12)°. These interactions form ring and chain patterns. The bi­phenyl twist angle is 79.95 (6)°.     

Ethyl 4‐do­decyl‐3,5‐di­methyl‐1H‐pyrrole‐2‐carboxyl­ate: intermolecular interactions in an amphiphilic pyrrole

The title compound, C₂₁H₃₇NO₂, is a new amphiphilic pyrrole with a long hydro­carbon chain, which will be used as a precursor for the synthesis of Langmuir–Blodgett films of porphyrins. Molecules related by an inversion centre are joined head‐to‐head into dimers by strong N—H?O hydrogen bonds. The dimers pack in the structure with their carbon chains parallel to one another, thereby forming alternating layers of carbon chains and pyrrole heads. The structure is further stabilized by two weak C—H?π intermolecular interactions, thereby saturating the hydrogen‐bonding capability of the aromatic π‐electron clouds.     

3‐Methyl 5‐isopropyl 2‐methoxy­imino­methyl‐6‐methyl‐4‐(3‐nitro­phenyl)‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate

The crystal structure of the title compound, C₂₀H₂₃N₃O₇, consists of relatively isolated mol­ecules. The substituted 1,4‐di­hydro­pyridine ring adopts a flattened boat conformation. Both ester groups, at positions 3 and 5, have cis,cis geometry. The phenyl ring is nearly planar and is approximately perpendicular to the 1,4‐di­hydro­pyridine ring (dihedral angle 87.70°).     

2,5‐Dichloro‐2,5‐dihydro­thio­phene 1‐oxide: determinaton of the complete stereochemistry

The title five‐membered heterocycle, C₄H₄Cl₂OS, adopts an envelope conformation with the S atom at the tip of the flap. All three ring substituents, viz. the sulfoxide O atom and the two Cl atoms, are cis to each other. The two C atoms α to the sulfoxide group are also bonded to chlorine. The electron‐withdrawing chlorine substituents give rise to weak C—H·O hydrogen bonds with the sulfoxide O atom of a symmetry‐related mol­ecule [H·O = 2.44 (2) and 2.61 (2) Å, C·O = 3.143 (3) and 3.302 (2) Å and C—H·O = 129.9 (19) and 135.1 (19)°]. There is also a possible weak C—H·Cl inter­action. Chains of mol­ecules held together by these weak inter­actions run parallel to the a axis.     

Bis­[N,N‐bis(2‐hydroxy­ethyl)­di­thio­carbamato]­di­methyl­tin(IV)

The title compound, [Sn(CH₃)₂(C₅H₁₀NO₂S₂)₂], has crystallographic mirror symmetry (C—Sn—C on mirror plane) and the coordination polyhedron around the Sn atom is a tetrahedron [C—Sn—C 139.3 (2)° and S—Sn—S 82.3 (1)°] distorted towards a skew‐trapezoidal bipyramid owing to an intramolecular Sn?S contact [3.0427 (6) Å]. The mol­ecules are linked into a linear chain by intermolecular O—H?O hydrogen bonds [O?O 2.646 (3) Å].