Two N‐substituted 3,5‐diphenyl‐2‐pyrazoline‐1‐thiocarboxamides

The structures of N‐ethyl‐3‐(4‐fluoro­phen­yl)‐5‐(4‐methoxy­phen­yl)‐2‐pyrazoline‐1‐thio­carboxamide, C₁₉H₂₀FN₃OS, (I), and 3‐(4‐fluoro­phen­yl)‐N‐methyl‐5‐(4‐methyl­phen­yl)‐2‐pyrazoline‐1‐thio­carboxamide, C₁₈H₁₈FN₃S, (II), have similar geometric parameters. The meth­oxy/methyl‐substituted phenyl groups are almost perpendicular to the pyrazoline (pyraz) ring [inter­planar angles of 89.29 (8) and 80.39 (10)° for (I) and (II), respectively], which is coplanar with the fluoro­phenyl ring [inter­planar angles of 5.72 (9) and 10.48 (10)°]. The pyrazoline ring approximates an envelope conformation in both structures, with the two‐coordinate N atom involved in an intra­molecular N—H⋯N_pyraz inter­action. In (I), N—H⋯O and C—H⋯S inter­molecular hydrogen bonds are the primary inter­actions, whereas in (II), there are no intermolecular hydrogen bonds.     

(1S,2R,2′S)‐ and (1S,2S,2′S)‐1‐phenyl‐2‐phenyl­thio‐2‐(tetra­hydro­pyran‐2′‐yl­thio)­ethanol diastereoisomers at 193 K

In the synthesis of 1‐phenyl‐2‐phenyl­thio‐2‐(tetra­hydro­pyran‐2‐yl­thio)­ethanol, C₁₉H₂₂O₂S₂, four diastereoisomers are formed. Two non‐centrosymmetric enantiomeric forms which crystallize in space groups P2₁2₁2₁ and Pna2₁ are presented. The former has an intramolecular hydrogen bond between the hydroxyl group and the O atom of the tetra­hydro­pyran ring. In the latter isomer, the hydroxyl group forms an intermolecular hydrogen bond to the O atom of the tetra­hydro­pyran­yl group of a neighbouring mol­ecule, joining the mol­ecules into chains in the c‐axis direction; the O?O distances are 2.962 (4) and 2.764 (3) Å, respectively. The tetra­hydro­pyran rings are in chair conformations in both isomers and the S side chain has an equatorial orientation in the former, but an axial orientation in the latter mol­ecule.     

Four (E,Z,E)‐1‐(4‐alkoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐trienes

The crystal structures of the four E,Z,E isomers of 1‐(4‐alk­oxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, namely (E,Z,E)‐1‐(4‐methoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₁₉H₁₇NO₃, (E,Z,E)‐1‐(4‐ethoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₂₀H₁₉NO₃, (E,Z,E)‐1‐(4‐nitro­phen­yl)‐6‐(4‐n‐propoxyphen­yl)hexa‐1,3,5‐triene, C₂₁H₂₁NO₃, and (E,Z,E)‐1‐(4‐n‐butoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₂₂H₂₃NO₃, have been determined. Inter­molecular N⋯O dipole inter­actions between the nitro groups are observed for the meth­oxy derivative, while for the eth­oxy derivative, two adjacent mol­ecules are linked at both ends through N⋯O dipole–dipole inter­actions between the N atom of the nitro group and the O atom of the eth­oxy group to form a supra­molecular ring‐like structure. In the crystal structures of the n‐prop­oxy and n‐but­oxy derivatives, the shortest inter­molecular distances are those between the two O atoms of the alk­oxy groups. Thus, the nearest two mol­ecules form an S‐shaped supra­molecular dimer in these crystal structures.     

A comparison of the ring conformational properties of two derivatives prepared from the same diene ­diacetate precursor

Results of single‐crystal X‐ray experiments performed for the title compounds, (1S,2R,3S,4R,5R)‐4‐benzyl­oxy‐2‐[1‐(benzyl­oxy)­allyl]‐5‐hydroxy­methyl‐2,3,4,5‐tetra­hydro­furan‐3‐ol, C₂₂H₂₆O₅, (I), and (3R,5S,6S,7S,8S)‐3,6‐bis­(benzyl­oxy)‐5‐iodo­methyl‐2,3,4,5‐tetra­hydro­furo­[3,2‐b]­furan‐2‐one, C₂₁H₂₁IO₅, (II), demonstrate that the tetra­hydro­furan ring that is common to both structures adopts a different conformation in each mol­ecule. Structural analyses of (I) and (II), which were prepared from the same precursor, indicate that their different conformations are caused by hydrogen‐bonding interactions in the case of (I) and the presence of a fused bicyclic ring system in the case of (II). Density functional theory calculations on simplified analogs of (I) and (II) are also presented.     

2‐Acetamido‐N‐benz­yl‐2‐(methoxy­amino)acetamides: functionalized amino acid anticonvulsants

In the crystal structure of 2‐acetamido‐N‐benz­yl‐2‐(methoxy­amino)acetamide (3L), C₁₂H₁₇N₃O₃, the 2‐acetyl­amino­acetamide moiety has a linearly extended conformation, with an inter­planar angle between the two amide groups of 157.3 (1)°. In 2‐acetamido‐N‐benz­yl‐2‐[meth­oxy(meth­yl)­amino]­acetamide (3N), C₁₃H₁₉N₃O₃, the planes of the two amide groups inter­sect at an angle of 126.4 (4)°, resulting in a chain that is slightly more bent. The replacement of the methoxy­amino H atom of 3L with a methyl group to form 3N and concomitant loss of hydrogen bonding results in some positional/thermal disorder in the meth­oxy­(methyl)­amino group. In both structures, in addition to classical N—H⋯O hydrogen bonds, there are also weak non‐standard C—H⋯O hydrogen bonds. The hydrogen bonds and packing inter­actions result in planar hydro­philic and hydro­phobic areas perpendicular to the c axis in 3L and parallel to the ab plane in the N‐meth­yl derivative. Stereochemical comparisons with phenytoin have identified two O atoms and a phenyl group as mol­ecular features likely to be responsible for the anticon­vulsant activities of these compounds.     

threo‐2‐(2,6‐Dimethoxy­phen­oxy)‐1‐(4‐hydr­oxy‐3,5‐dimethoxy­phenyl)­propane‐1,3‐diol: a conformational study

In the crystal structure of the title compound, C₁₉H₂₄O₈, the mol­ecules adopt a conformation in which the bulky 2,6‐dimethoxy­phen­oxy and 4‐hydr­oxy‐3,5‐dimethoxy­phen­yl groups are almost as far apart as possible. The C(aryl)·C(aryl) distance is 4.8766 (19) Å, which is close to the calculated maximum value (4.92 Å). The C(aryl)—C—C—O(aryloxy) torsion angle is 173.76 (11)° and the C(benzylic)—C—O—C(aryl) torsion angle is 149.09 (11)°. The conformation is compared with those of related lignin model compounds. The hydrogen‐bonding pattern is discussed in terms of graph‐set theory.     

The conversion of a pyrrole trimer derivative into a 4,5,6,7‐tetra­hydro‐4‐­(pyrrol‐2‐yl)indol‐7‐yl­tosyl­aminoindole

Vilsmeier formyl­ation of trans‐1‐(4‐methyl­phenyl­sulfonyl)‐2,5‐bis(pyrrol‐2‐yl)­pyrrolidine leads to cleavage of the central ring then a reclosure resulting in the formation of trans‐N‐[2‐formyl‐4‐(5‐formyl­pyrrol‐2‐yl)‐4,5,6,7‐tetra­hydro­indol‐7‐yl]­toluene­sulfon­amide, C₂₁H₂₁N₃O₄S.     

Trifluoro­meth­yl derivatives of penta­cyclo­[5.4.0.02,6.03,10.05,9]undeca­ne

Three cage‐like polycyclic compounds, viz.exo‐8‐(trifluoro­meth­yl)­penta­cyclo­[5.4.0.0^2,6.0^3,10.0^5,9]undecan‐endo‐8‐ol, C₁₂H₁₃F₃O, 5‐(trifluoro­meth­yl)‐4‐oxahexa­cyclo­[5.4.1.0^2,6.0^3,10.0^5,9.0^8,11]­dodecan‐3‐ol, C₁₂H₁₁F₃O₂, and N‐[exo‐11‐(trifluoro­meth­yl)‐endo‐11‐(trimethyl­sil­yl­oxy)­penta­cyclo­[5.4.0.0^2,6.0^3,10.0^5,9]undecan‐8‐yl­idene]aniline meth­anol solvate, C₂₁H₂₄F₃NOSi·CH₄O, were obtained from the corresponding oxo derivatives by nucleophilic trifluoro­methyl­ation with (tri­fluorometh­yl)trimethyl­silane in 1,2‐dimethoxy­ethane solution in the presence of CsF. The crystal structures show that the addition of trifluoro­methanide occurs exclusively from the exo face of the polycyclic ketones. Further examination of the crystal structures, together with that of the starting penta­cyclo­[5.4.0.0^2,6.0^3,10.0^5,9]undecane‐8,11‐dione, C₁₁H₁₀O₂, showed that increasing substitution at the 8‐ and/or 11‐positions in the cage mol­ecules increases the non‐bonded intra­molecular C·C distances at the mouth of the cage and changes the puckering of the five‐membered rings involving the 8‐ and 11‐positions from an envelope towards a distorted half‐chair conformation. Inter­molecular co‐operative O—H·O hydrogen bonds in the endo‐8‐ol compound link the mol­ecules into tetra­mers.     

(μ‐Tri‐tert‐butoxysilanethiol­ato)­bis[(tetra­hydro­furan)lithium(I)] and catena‐poly[[bis­(μ‐tri‐tert‐butoxy­silanethiol­ato)dilithium(I)]‐μ‐dimethoxy­ethane]: solvent coordination as the structure‐forming factor

The title compounds, μ‐(tri‐tert‐butoxy­silanethiol­ato‐κ²S:S)‐bis[(tetra­hydro­furan‐κO)lithium(I)], [Li₂(C₁₂H₂₇O₃SSi)₂(C₄H₈O)₂], (I), and catena‐poly[[bis­(μ‐tri‐tert‐butoxysilanethiol­ato)‐1:2κ²S;1κS:2κS,O‐dilithium(I)]‐μ‐dimethoxy­ethane‐κ²O:O′], [Li₂(C₁₂H₂₇O₃SSi)₂(C₄H₁₀O₂)]_n, (II), were obtained by the reaction of tri‐tert‐butoxy­silanethiol with metallic lithium. The crude product, when recrystallized from tetra­hydro­furan (THF) yields (I), and when recrystallized from 1,2‐dimethoxy­ethane (DME) gives (II). Compound (I) forms centrosymmetric dimers in the solid state with an Li₂S₂ central core, whereas (II) forms infinitely long chains, in which the centrosymmetric dimeric units are linked together by the bidentate DME ligand (also residing on an inversion centre), thus forming a coordination polymer. The formation of a one‐dimensional structure in (II) is a consequence of replacement of a monodentate THF solvent mol­ecule with a bidentate DME mol­ecule.     

Isomeric Schiff bases related by dual imino‐group reversals

Two isomeric pairs of Schiff bases, N,N′‐bis­(2‐methoxy­benzyl­idene)‐p‐phenyl­enediamine, C₂₂H₂₀N₂O₂, (I), and 2,2′‐dimeth­oxy‐N,N‐(p‐phenyl­enedimethyl­ene)dianiline, C₂₂H₂₀N₂O₂, (II), and (E,E)‐1,4‐bis­(3‐iodo­phen­yl)‐2,3‐diaza­buta‐1,3‐diene (alternative name: 3‐iodo­benzaldehyde azine), C₁₄H₁₀I₂N₂, (III), and N,N′‐bis­(3‐iodo­phen­yl)ethylenedi­imine, C₁₄H₁₀I₂N₂ [JAYFEV; Cho, Moore & Wilson (2005). Acta Cryst. E 61 , o3773–o3774], differ pairwise only in the orientation of their imino linkages and in all four individual cases occupy inversion centers in the crystal, yet all four compounds are found to assume unique packing arrangements. Compounds (I) and (II) differ substantially in mol­ecular conformation, possessing angles between their ring planes of 12.10 (15) and 46.29 (9)°, respectively. Compound (III) and JAYFEV are similar to each other in conformation, with angles between their imino linkages and benzene rings of 11.57 (15) and 7.4 (3)°, respectively. The crystal structures are distinguished from each other by different packing motifs involving the functional groups. Inter­molecular contacts between meth­oxy groups define an R₂²(6) motif in (I) but a C(3) motif in (II). Inter­molecular contacts are of the I⋯I type in (III), but they are of the N⋯I type in JAYFEV.     

Rotenone α‐oxime

The structure determination of the title compound, rotenone α‐oxime [systematic name: 1,2,12,12a‐tetra­hydro‐8,9‐di­meth­oxy‐2‐(1‐methyl­ethenyl)‐[1]­benzo­py­rano­[3,4‐b]­furo­[2,3‐h][1]benzo­pyran‐6(6H)‐one oxime], C₂₃H₂₃NO₆, confirms that the mol­ecule has an approximately V‐shaped structure. One of the rings has a typical cyclo­hexene‐like monoplanar conformation and the central ring adopts a 1,2‐diplanar conformation.     

New palladium complexes with phosphino‐ and phosphinitopyridine ligands

Three new palladium complexes containing a difunctional P,N‐chelate, namely tris­(chloro­{[1‐methyl‐1‐(6‐methyl‐2‐pyridyl)ethoxy]diphenylphospine‐κ²N,P}methyl­palladium(II)chloro­form solvate, 3[Pd(CH₃)Cl(C₂₁H₂₂NOP)]·CHCl₃, (III), dichloro­[2‐(2,6‐dimethyl­phen­yl)‐6‐(diphenyl­phosphinometh­yl)­pyridine‐κ²N,P]palladium(II), [PdCl₂(C₂₆H₂₄NP)], (IV), and chloro­[2‐(2,6‐dimethyl­phen­yl)‐6‐(diphenyl­phos­phino­meth­yl)pyridine‐κ²N,P]methyl­palladium(II), [Pd(CH₃)Cl(C₂₆H₂₄NP)], (V), are reported. Geometric data and the conformations of the ligands around the metal centers, as well as slight distortions of the Pd coordination environments from idealized square‐planar geometry, are discussed and compared with the situations in related compounds. Non‐conventional hydrogen‐bond inter­actions (C—H⋯Cl) have been found in all three complexes. Compound (III) is the first six‐membered chloro–meth­yl–phosphinite P,N‐type Pd^II complex to be structurally characterized.     

1,3‐Dibenzoylimidazolidine‐2‐thione and 1,3‐dibenzo­yl‐3,4,5,6‐tetra­hydro­pyrimidine‐2(1H)‐thione

The title compounds, 1,3‐dibenzo­ylimidazolidine‐2‐thione, C₁₇H₁₄N₂O₂S, (I), and 1,3‐dibenzo­yl‐3,4,5,6‐tetra­hydro­pyrimidine‐2(1H)‐thione, C₁₈H₁₆N₂O₂S, (II), were obtained from the reactions of imidazolidine‐2‐thione and 1,4,5,6‐tetra­hydro­pyrimidine‐2‐thiol, respectively, with benzoyl chloride. Compounds (I) and (II) contain, respectively, imidazolidinethione [C=S = 1.6509 (14) Å] and ­pyrimidinethione [C=S = 1.6918 (19) Å] moieties bonded to two benzoyl rings. The mol­ecules of (I) exhibit C₂ symmetry, the C=S bond lying along the twofold rotation axis, while the mol­ecules of (II) have mirror symmetry (C_s). The imida­zolidine ring in (I) is essentially planar, while the pyrimidine ring in (II) adopts a boat conformation. Mol­ecules of (I) are linked by weak inter­molecular C—H⋯O inter­actions, while mol­ecules of (II) are held together by van der Waals inter­actions.     

Inter­actions of thia­mine with polymeric halogenocadmate anions in the organic–inorganic hybrid compound (thia­minium)[Cd3Br4.4Cl3.6]

The structure of poly[3‐[(4‐amino‐2‐methylpyrimidin‐1‐ium‐5‐yl)meth­yl]‐5‐(2‐hydroxy­ethyl)‐4‐methyl­thia­zolium octa‐μ‐bromo/chloro­(4.4/3.6)‐tricadmate(II)], {(C₁₂H₁₈N₄OS)[Cd₃ Br_4.41Cl_3.59]}_n consists of hydrogen‐bonded thia­mine mol­ecules and polymeric cadmium bromide/chloride anions in an organic–inorganic hybrid fashion. The one‐dimensional anion ribbons are formed by edge‐sharing octa­hedra and vertex‐sharing tetra­hedra. Thia­mine mol­ecules adopting the S conformation are linked to anions via three types of inter­actions, namely an N(amino)—H⋯anion⋯thia­zolium bridging inter­action, an N(pyrimidine)—H⋯anion hydrogen bond and an O(hydr­oxy)—H⋯anion hydrogen bond.     

Supra­molecular motifs in 1‐(2‐cyano­ethyl)thymine and 1‐(3‐cyano­propyl)­thymine

In both 1‐(2‐cyano­ethyl)thymine [systematic name: 3‐(5‐methyl‐2,4‐dioxo‐1,2,3,4‐tetra­hydro­pyrimidin‐1‐yl)propane­nitrile], C₈H₉N₃O₂, (I), and 1‐(3‐cyano­propyl)thymine [systematic name: 4‐(5‐methyl‐2,4‐dioxo‐1,2,3,4‐tetra­hydro­pyrimidin‐1‐yl)butane­nitrile], C₉H₁₁N₃O₂, (II), the core of the supra­molecular structure is formed by centrosymmetric dimers generated by N—H⋯O hydrogen bonds. Further weak hydrogen bonds of C—H⋯O and C—H⋯N types generate mol­ecular tapes and sheets that resemble those in uracil and its methyl derivatives. The steric hindrance that arises from the cyano­alkyl substituents perturbs the conformations of the tapes and sheets.     

Supramolecular aggregation of two hydroxy­carboxylic acid derivatives

The crystal structures of 7,7‐dicyclo­but­yl‐5‐hydroxy­meth­yl‐6‐oxabicyclo­[3.2.1]octa­ne‐1‐carboxylic acid, C₁₇H₂₆O₄, (I), and 1‐(hydroxy­meth­yl)‐7‐oxaspiro­[bicyclo­[3.2.1]octa­ne‐6,1′‐cyclo­penta­ne]‐5‐carboxylic acid, C₁₃H₂₀O₄, (II), determined at 170 K, show that the conformation of the hydroxy­meth­yl group (anti or gauche) affects the dimensionality (one‐ or two‐dimensional) of the supramolecular structures via O—H⋯O hydrogen bonds. In (I), the carbox­yl and hydroxy­meth­yl groups inter­act with themselves, forming a one‐dimensional step‐ladder, while in (II), a two‐dimensional structure is made up of carboxylic acid centrosymmetric R₂²(8) dimers connected by hydrox­yl‐to‐ether contacts.     

Supramolecular hydrogen‐bonded hexamers in two 5‐aryl‐3‐methyl‐1‐phenyl‐1,6,7,8‐tetra­hydro­pyrazolo­[3,4‐b][1,4]­diazepines

In both title compounds, i.e. 3‐methyl‐1,5‐di­phenyl‐1,6,7,8‐tetra­hydro­pyrazolo­[3,4‐b][1,4]­diazepine, C₁₉H₁₈N₄, (I), and 5‐(4‐chloro­phenyl)‐3‐methyl‐1‐phenyl‐1,6,7,8‐tetra­hydro­pyra­zolo­[3,4‐b][1,4]­diazepine, C₁₉H₁₇ClN₄, (II), an N—H?N hydrogen bond links six mol­ecules to form an R(30) ring. Compound (I) crystallizes in the R space group and (II) crystallizes in P with three mol­ecules in the asymmetric unit. The mol­ecule of (I) contains a disordered seven‐membered ring.     

(5S*,6R*)‐1,7‐Dioxa­di­spiro­[4.0.4.4]­tetra­decane‐2,8‐dione

The title compound, C₁₂H₁₆O₄, (I), was prepared by oxidation of (5S*,6R*)‐1,7‐di­oxa­di­spiro­[4.0.4.4]­tetra­decane‐2,8‐diol us­ing silver(I) carbonate and posesses a cis configuration of the two five‐membered‐ring lactones fused spiro to the six‐membered carbocycle, which has a chair conformation. It represents an exceptional structure for bis‐tetra­hydro­furan units, which are interesting building blocks in natural products. The synthesis, spectroscopic data and X‐ray structural analysis are described. The crystal contains discrete mol­ecules separated by normal van der Waals distances.     

N‐Benzyl­tetra­hydro­pyrido‐anellated thio­phene derivatives: new anti­cholinesterases

The title compounds, tert‐butyl 6‐benzyl‐2‐(3,3‐diethyl­ureido)‐4,5,6,7‐tetra­hydro­thieno[2,3‐c]pyridine‐3‐carboxyl­ate, C₂₄H₃₃N₃O₃S, (I), 7‐benzyl‐2‐diethyl­amino‐5,6,7,8‐tetra­hydro‐3‐oxa‐9‐thia‐1,7‐diaza­fluoren‐4‐one, C₂₀H₂₃N₃O₂S, (II), and N‐(7‐benzyl‐4‐oxo‐5,6,7,8‐tetra­hydro‐4H‐3,9‐dithia‐1,7‐diaza­fluoren‐2‐yl)benzamide, C₂₃H₁₉N₃O₂S₂, (III), form monoclinic crystal systems. In (I) and (II), the mol­ecules are linked into a three‐dimensional framework by weak inter­molecular C—H⋯O=C hydrogen bonds, whereas in (III) stronger inter­molecular N—H⋯O=C inter­actions are observed. The conformation of (I) is further stabilized by an intra­molecular N—H⋯O=C hydrogen bond, which effects the planarity of the ureido­thio­phene­carboxyl­ate moiety.     

Solvent–metal interactions in bis[1,2‐dicarba‐closo‐dodecaboran(12)‐1‐yl]mercury(II) dichloromethane solvate and bis[1,12‐dicarba‐closo‐dodecaboran(12)‐1‐yl]mercury(II) tetrahydrofuran solvate

The title compounds, bis­[1,2‐dicarba‐closo‐dodecaboran(12)‐1‐yl]­mercury(II) di­chloro­methane solvate, [Hg(C₂B₁₀H₁₁)₂]·CH₂Cl₂, (I), and bis­[1,12‐dicarba‐closo‐dodecaboran(12)‐1‐yl]­mercury(II) tetra­hydro­furan solvate, [Hg(C₂B₁₀H₁₁)₂]·C₄H₈O, (II), were prepared in excellent yields using a robust synthetic procedure involving the reaction of HgCl₂ with the appropriate monoli­thiocarborane. X‐Ray analysis of the products revealed strong interactions between the Hg atoms in both complexes and the respective lattice solvent. The distances between the Hg^II centers and the Cl atoms of the dichloromethane solvent molecule in the ortho‐carborane derivative, (I), and the O atom of the tetra­hydro­furan molecule in the para‐carborane complex, (II), are shorter than the sums of the van der Waals radii for Hg and Cl (3.53 Å), and Hg and O (3.13 Å), respectively, indicating moderately strong interactions. There are two crystallographically independent mol­ecules in the asymmetric unit of both compounds, which, in each case, are related by differing relative positions of the cages.