25,27:26,28‐Bis(3,9‐dioxa‐6‐aza­undecane‐1,11‐dioxy)­calix­[4]­arene tetrahydrate

The title compound, C₄₄H₅₄N₂O₈·4H₂O, has twofold crystallographic symmetry and consists of a calix­[4]­arene moiety with four phenyl rings arranged alternately in anti‐orientation fashion and two aza­crown units attached on the lower rims of calix­[4]­arene. This seems to offer a big cavity inside the mol­ecule which might possess a potential for forming host–guest complexes.     

Cone and 1,3‐alternate conformers of 1,3‐bis­(ethoxy­carbonyl­methoxy)‐2,4‐di­hydroxy­calix­[4]­arene and 1,2,3,4‐tetrakis­(ethoxy­carbonyl­methoxy)­calix­[4]­arene

The two title ethoxy­carbonyl­methoxy derivatives of calix­[4]­arene, namely diethyl 2,4‐di­hydroxy­calix­[4]­arene‐1,3‐diyldi(oxy­ace­tate), C₃₆H₃₆O₈, (I), and tetraethyl ­calix­[4]­arene‐1,2,3,4‐tetra­yltetra­(oxy­acetate), C₄₄H₄₈O₁₂, (II), form two different conformations, viz. a cone in (I), where intramol­ecular hydrogen bonds are formed through OH groups in a partially substituted calix­[4]­arene, and a 1,3‐alternate form of a completely substituted calix­[4]­arene in (II). A unique three‐dimensional array of mol­ecules exists in (II), with the channels extended along the entire crystal.     

5,11,17,23‐Tetra‐tert‐butyl‐25,26,27,28‐tetrakis(2‐cyano­benzyl­oxy)‐2,8,14,20‐tetra­thia­calix­[4]­arene–di­chloro­methane (1/2)

A new p‐tert‐butyl­thia­calix­[4]­arene derivative, C₇₂H₆₈N₄O₄S₄·2CH₂Cl₂, has been synthesized and is comprised of one tetra‐p‐tert‐butyltetrakis(2‐cyano­benzyl­oxy)­tetra­thia­calix­[4]arene and two di­chloro­methane mol­ecules. The calix­[4]­arene mol­ecule is centrosymmetric and adopts an unusual 1,2‐alternate conformation viaπ–π interactions between adjacent cyano­phenyl rings on the lower rim of the parent thia­calix­[4]­arene system.     

(5,11,17,23‐Tetra‐tert‐butyl‐26,28‐di­hydroxy­calix­[4]­arene‐25,27‐dioxy)­di­acetic acid N,N‐di­methyl­form­amide trisolvate

The title compound, C₄₈H₆₀O₈·3C₃H₇NO, is a derivative of calix­[4]­arene in the cone conformation, modified with distal carboxylic acid functional groups at the lower rim. A clathrate di­methyl­form­amide (DMF) mol­ecule is located within the calix­[4]­arene cone, and two DMF solvate mol­ecules participate in hydrogen bonding with the carboxylic acid groups. Intramolecular hydrogen bonds are also formed between the OH groups and the adjacent ether groups in the partially substituted calix­[4]­arene.     

2,4‐Di­hydroxy‐1,3‐bis­(methoxy­carbonyl­methoxy)­calix­[4]­arene and 1,3‐bis­(ethoxy­carbonyl­methoxy)‐2,4‐di­hydroxy­calix­[4]­arene chloro­form solvate

The two title calix­[4]­arene compounds, C₃₄H₃₂O₈, (I), and C₃₆H₃₆O₈·CH₃Cl, (II), respectively, which differ only in the size of the alkyl function on the pendant ester group, are compared. Compound (I) forms a novel supramolecular array, whilst (II) fails to do so due to accommodating a chloro­form guest molecule in the lower‐rim cavity.     

Two isomers of 2,4‐di­benzyl‐8‐azabicyclo­[3.2.1]­octan‐3‐ol

The crystal structures of the title compounds, 2α,4α‐di­benzyl‐3α‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3α‐ol), C₂₂H₂₇NO, (I), and 2α,4α‐di­benzyl‐3β‐tropanol (2α,4α‐di­benzyl‐8‐methyl‐8‐aza­bi­cyclo­[3.2.1]­octan‐3β‐ol), C₂₂H₂₇NO, (II), show that both compounds have a piperidine ring in a chair conformation and a pyrrolidine ring in an envelope conformation. Isomer (I) is asymmetric, the benzyl groups having different orientations, whereas isomer (II) is mirror symmetric, and the N and O atoms, the C atom attached to the hydroxy group, and the methyl C atom attached to the N atom lie on the mirror plane. In the crystal structures of both (I) and (II), the mol­ecules are linked together by intermolecular O—H⋯N hydrogen bonds to form chains that run parallel to the a direction in (I) and parallel to b in (II).     

(Z)‐2‐(3‐Hydroxy‐4‐methoxybenzylidene)‐1‐azabicyclo[2.2.2]octan‐3‐one

Crystals of the title compound, C₁₅H₁₇NO₃, were obtained from a condensation reaction of 3‐hydroxy‐4‐methoxy­benz­aldehyde with 1‐aza­bi­cyclo­[2.2.2]­octan‐3‐one and subsequent crystallization of the product from methanol. The title compound, containing a double bond that connects the aza­bicyclic ring system to the 3‐hydroxy‐4‐methoxy­benzyl­idene group, was obtained with Z geometry.     

A uranyl ion complex of N‐methyl‐p‐tert‐butyl­dihomo­ammonio­calix­[4]­arene with di­aqua­di­pyridine­lithium as counter‐ion

The title complex, di­aqua­di­pyridine­lithium (N‐methyl‐p‐tert‐butyl­dihomo­ammonio­calix­[4]­arene‐κ⁴O)­dioxouranium(VI) tri­pyridine solvate monohydrate, [Li(C₅H₅N)₂(H₂O)₂][UO₂(C₄₆H₅₈NO₄)]·3C₅H₅N·H₂O, contains an `internal' tetraphenoxide‐coordinated uranyl complex of the macrocycle, in which the protonated N atom is involved in an intramolecular hydrogen bond with the uranyl oxo group located in the cavity. The Li⁺ ion is in a tetrahedral environment and its two water ligands are involved in hydrogen bonds with two phenoxide O atoms, two pyridine mol­ecules and one water mol­ecule. This arrangement is compared with those obtained previously for other homo­aza­calixarenes and also for homo­oxa­calixarenes in the presence of alkali metal hydro­xides.     

1,3‐Bridged p‐methyloctahomotetraoxacalix[4]arene–bis‐crown‐3

The title compound, 13,21,35,43‐tetra­methyl‐3,6,9,17,25,28,31,39,46,49‐decaoxahepta­cyclo­[21.21.3.3^11,33.0^2,41.0^10,15.0^19,24.0^32,37]pentaconta‐1,10,12,14,19,21,23,32,34,36,41,43‐dodecaene, C₄₄H₅₂O₁₀, differs from previously reported 1,3‐bridged calix­[4]­arene–bis‐crown compounds in having an enlarged calixarene ring and shorter polyoxy­ethyl­ene bridges. The cavity is partly filled by the bridges.     

Two 5‐oxa‐2,6‐diazaspiro[3.4]octan‐1‐one derivatives from the [3+2] cyclo­addition of methylenelactams with nitrones

The two title 5‐oxa‐2,6‐di­aza­spiro­[3.4]­octan‐1‐one adducts, 7‐benzoyl‐2‐(4‐methoxy­phenyl)‐6‐phenyl‐5‐oxa‐2,6‐di­aza­spiro­[3.4]­octan‐1‐one, C₂₅H₂₂N₂O₄, (III), and 6‐tert‐butyl‐2‐(4‐methyl­phenyl)‐7‐phenyl‐5‐oxa‐2,6‐di­aza­spiro­[3.4]­octan‐1‐one, C₂₂H₂₆N₂O₂, (IV), were obtained from a stereospecific [3+2] 1,3‐cyclo­addition of 3‐methyl­ene azetidin‐2‐ones as dipolaro­philes with nitro­nes. The lactam ring is conjugated with the p‐­methoxy­phenyl or p‐methyl­phenyl moiety. The envelope conformations of the isoxazolidine rings in (III) and (IV) are different, leading the substituents to be pseudo‐axial in (III) and pseudo‐equatorial in (IV).     

2‐(6‐Bromo­pyridin‐2‐yl)‐6‐methyl‐[1,3,6,2]­diox­aza­borocane,a new stable (pyridin‐2‐yl)­boronic acid derivative

The crystal structure of the first reported non‐substituted N‐methyl­diox­aza­borocane confirms that the presence of a methyl group attached to the N atom introduces an NB bond length that is longer than that in a simple diox­aza­borocane ring. The presence of more N atoms in the vicinity of the B atom in the title compound [systematic name: 6a‐(6‐bromo­pyridin‐2‐yl)‐3a‐methyl‐2,3,4,5‐tetra­hydro‐1,6‐dioxa‐3a‐aza‐6a‐borapentalene], C₁₀H₁₄BBrN₂O₂, does not modify significantly any structural parameter in the diox­aza­borocane ring. On the other hand, a small asymmetry appears in the bond angles of the pyridine C atom next to the B atom.     

Di­spiro­[fluorene‐9,5′‐[1,2,3,4]­tetra­thia­ne‐6′,9′′‐fluorene]

The tetra­thia­ne ring of the title compound, C₂₆H₁₆S₄, has a chair conformation and the mol­ecule has approximate C₂ symmetry. Each of the two fluorene ring systems is virtually planar, with the ring planes intersecting at an angle of 67.58 (5)°. This novel compound has been formed as a side product from the treatment of 9H‐fluorene‐9‐thione with methyl N‐[(benzyl­idene)­phenyl]­glycinate in the presence of LiBr and 1,6‐di­aza­bi­cyclo­[5.4.0]­un­decane.     

Four 3‐cyano­difur­aza­nyl ethers: potential propellants

In earlier papers, we described the synthesis and structures of bis(3‐nitro­fur­azan‐4‐yl) ether, C₄N₆O₇, (I), bis­[3‐(nitro‐N,N,O‐azoxy)­fur­azan‐4‐yl] ether, C₄N₁₀O₉, (II), and bis[3‐­(5H‐[1,2,3]­triazolo­[4,5‐c]­fur­azan‐5‐yl)­fur­azan‐4‐yl] ether, C₈N₁₄O₅, (III). Here we compare the structures of (I)–(III) with those of four 3‐cyano­difur­aza­nyl ethers, namely bis(3‐­cyano­fur­azan‐4‐yl) ether, C₆N₆O₃, (IV), 3‐cyano­fur­aza­nyl 3‐­nitro­fur­aza­nyl ether, C₅N₆O₅, (V), 3,4‐bis(3‐cyano­fur­azan‐4‐­yl­oxy)­fur­azan, C₈N₈O₅, (VI), and bis­[3‐(3‐cyano­fur­azan‐4‐­yl­oxy)­fur­azan‐4‐yl]­diazene, C₁₀N₁₂O₆, (VII). It was found that the geometric parameters of the difur­aza­nyl ether fragments are similar in these structures and therefore not influenced by substituent effects; however, the conformation of this fragment is different, viz. structures (I), (III), (V) and (VI) have approximate C₂ symmetry, and structures (II), (IV) and (VII) have C_s symmetry. Dense crystal packing (1.626–1.898 Mg m⁻³) is characteristic for all these hydrogen‐free compounds. A linear correlation is also determined between crystal density and `molecular density' (M/V), where M is the mass of a mol­ecule and V is the molecular volume.     

Tris­[2‐(benzoyl­amino)­ethyl]­amine

Tris­[2‐(benzoyl­amino)­ethyl]­amine [alternatively, N,N′,N′′‐(nitrilo­tri­ethyl)­tri­benz­amide], C₂₇H₃₀N₄O₃, adopts a folded structure, forming a symmetrical cavity with an average depth of 7.3 Å and width ranging from 4.1–4.4 Å. The folded structure is a result of one intramolecular N—H?O hydrogen bond. A linear chain motif along the c axis best describes the extended intermolecular N—H?O hydrogen bonding.     

6‐(2‐Fluorobenzylidene)‐2‐[1‐(2‐fluoro‐4‐biphenyl)ethyl]thiazolo[3,2‐b][1,2,4]triazol‐5(6H)‐one

The title compound, C₂₅H₁₇F₂N₃OS, was synthesized from 6‐(benzyl­idene)­thia­zolo­[3,2‐b][1,2,4]triazol‐5(6H)‐one. The fused thia­zolo­[3,2‐b][1,2,4]triazole system is essentially planar, and bifurcated C—H⋯O, C—H⋯N and C—H⋯F interactions are present between mol­ecules.     

Ethyl N‐[2‐(hydroxy­acetyl)­phenyl]­carbamate,ethyl N‐[2‐(hydroxy­acetyl)‐4‐iodo­phenyl]­carbamate and ethyl N‐[2‐(hydroxy­acetyl)‐4‐methyl­phenyl]­carbamate

In ethyl N‐[2‐(hydroxy­acetyl)phenyl]carbamate, C₁₁H₁₃NO₄, all of the non‐H atoms lie on a mirror plane in the space group Pnma; the mol­ecules are linked into simple chains by a single C—H⋯O hydrogen bond. The mol­ecules of ethyl N‐[2‐(hydroxy­acetyl)‐4‐iodo­phenyl]carbamate, C₁₁H₁₂INO₄, are linked into sheets by a combination of O—H⋯I and C—H⋯O hydrogen bonds and a dipolar I⋯O contact. Ethyl N‐­[2‐(hydroxy­acetyl)‐4‐methyl­phenyl]carbamate, C₁₂H₁₅NO₄, crystallizes with Z′ = 2 in the space group P; pairs of mol­ecules are weakly linked by an O—H⋯O hydrogen bond and these aggregates are linked into chains by two independent aromatic π–π stacking inter­actions.     

1‐[4‐(Methyl­sulfonyl)­phenyl]‐5‐phenyl‐1H‐pyrazole derivatives

Three related compounds containing a pyrazole moiety with vicinal phenyl rings featuring a methyl­sulfonyl substituent are described, namely 3‐methyl‐1‐[4‐(methyl­sulfonyl)­phenyl]‐5‐phenyl‐1H‐pyrazole, C₁₇H₁₆N₂O₂S, ethyl 1‐[4‐(methyl­sul­fonyl)­phenyl]‐5‐phenyl‐1H‐pyrazole‐3‐carboxyl­ate, C₁₉H₁₈N₂O₄S, and 1‐[4‐(methyl­sulfonyl)­phenyl]‐3‐[3‐(morpholino)­phenoxy­methyl]‐5‐phenyl‐1H‐pyrazole, C₂₇H₂₇N₃O₄S. The design of these compounds was based on celecoxib, a selective cyclo­oxy­genase‐2 (COX‐2) inhibitor, in order to study the influence of various substituents on COX‐2 and 5‐lipoxy­genase (5‐LOX) inhibition.     

Precursor of a β‐lactamase inhibitor: allyl (4S,8S,9R)‐10‐[(E)‐ethyl­idene]‐4‐methoxy‐11‐oxo‐1‐aza­tri­cyclo­[7.2.0.03,8]­undec‐2‐ene‐2‐carboxyl­ate

The molecular structure of the title tricyclic compound, C₁₇H₂₁NO₄, which is the immediate precursor of a potent synthetic inhibitor {Lek157: sodium (8S,9R)‐10‐[(E)‐ethyl­idene]‐4‐methoxy‐11‐oxo‐1‐aza­tri­cyclo­[7.2.0.0^3,8]­undec‐2‐ene‐2‐carboxyl­ate} with remarkable potency, provides experimental evidence for the previously modelled relative position of the fused cyclo­hexyl ring and the carbonyl group of the β‐lactam ring, which takes part in the formation of the initial tetrahedral acyl–enzyme complex. In this hydro­phobic mol­ecule, the overall geometry is influenced by C—H?O intramolecular hydrogen bonds [3.046 (4) and 3.538 (6) Å, with corresponding normalized H?O distances of 2.30 and 2.46 Å], whereas the mol­ecules are interconnected through intermolecular C—H?O hydrogen bonds [3.335 (4)–3.575 (5) Å].     

1,4‐Di­aza­bi­cyclo­[2.2.2]­octane‐1,4‐diium trichromate

The title compound, (C₆H₁₄N₂)[Cr₃O₁₀], consists of a di­aza­bi­cyclo­[2.2.2]­octane‐1,4‐diium cation and a discrete trichromate anion linked by an N—H⋯O hydrogen bond. Three CrO₄ tetrahedra are joined via shared O atoms to form the trichromate anion. Supramolecular rings, which can be described by the graph‐set motif (26), are built via N—H⋯O hydrogen bonds, and C—H⋯O interactions play lesser roles in forming the structure.     

(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.