An Efficient Synthesis of 3,3′,4,4′‐Tetrahydro‐4,4′‐bibenzo[e][1,3]oxazine‐2,2′‐dione Derivatives with the Aid of Low‐valent Titanium

Synthesis of 3,3′,4,4′‐tetrahydro‐4,4′‐bibenzo[e][1,3]oxazine‐2,2′‐diones via reaction of salicylidendphenylhydrazone and triphosgene with the aid of low‐valent titanium reagent is described. This method has the advantages of accessible starting materials, good yields and short reaction time.     

Polymorphism and phase transition behavior of 6,6′‐bis(chloromethyl)‐1,1′,4,4′‐tetramethyl‐3,3′‐(p‐phenylenedimethylene)bis(piperazine‐2,5‐dione)

A crystallographic investigation of the title compound, C₂₂H₂₈Cl₂N₄O₄, using crystals obtained under different crystallization conditions, revealed the presence of two distinct polymorphic forms. The molecular conformation in the two polymorphs is very different: one adopts a `C' shape, whereas the other adopts an `S' shape. In the latter, the molecule lies across a crystallographic twofold axis. The `S'‐shaped polymorph undergoes a reversible orthorhombic‐to‐monoclinic phase transition on cooling, whereas the structure of the `C'‐shaped polymorph is temperature insensitive.     

Synthesis of Hexahydrospiro[pyrazolo[3,4‐b]quinoline‐4,1′‐pyrrolo[3,2,1‐ij]quinoline‐2′,5(1H,4′H)‐diones] from 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione Using Fe3O4@Cu(OH)x as a Nanocatalyst

The tricyclic isatin, 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione, undergoes three‐component, one‐pot reactions with 1‐aryl‐3‐methylpyrazole‐5‐amines and cyclohexane‐1,3‐diones producing hexacyclic spiro products, hexahydrospiro[pyrazolo[3,4‐b]quinoline‐4,1‐pyrrolo[3,2,1‐ij]quinoline‐2′,5(1H,4′H)‐diones]. Comparable spiro condensation products are also obtained using 4‐hydroxy‐2H‐1‐benzopyran‐2‐one in place of cyclohexane‐1,3‐diones.     

Synthesis and Characterization of (2E,2 E)‐3,3‐((9,9‐diocyl‐9H‐flourene‐2,7‐diyl)bis(4,1‐phenylene))bis(2‐cyanoacylic acid) as a Symmetrical Metal‐free Organic Dye

In this study a novel symmetrical metal‐free organic dye for applications in dye‐sensitized solar cells (DSSCs) was synthesized. This dye ( D ) was designed with A–π–D–π–A framework and synthesized with 9,9‐dioctylfluorene as electron donor, phenylene as π‐spacer and cyanoacetic acid as electron acceptor. The chemical structure of product was determined using UV‐Vis, FT‐IR, CNMR, HNMR spectroscopy techniques. The presence of a phenylene π‐bridge between the donor and the acceptor units and the di‐anchoring moieties in this structure led to enhancement of conjugation lengths and molar extinction coefficient (ε) that is promising for further improvement of the conversion efficiency of DSSCs.     

Comparative study on polyimides from isomeric 3,3′‐, 3,4′‐, and 4,4′‐linked bis(thioether anhydride)s

Three isomeric bis(thioether anhydride) monomers, 4,4′‐bis(2,3‐dicarboxyphenylthio) diphenyl ketone dianhydride (3,3′‐PTPKDA), 4,4′‐bis(3,4‐dicarboxyphenylthio) diphenyl ketone dianhydride (4,4′‐PTPKDA), and 4‐(2,3‐dicarboxyphenylthio)‐4′‐(3,4‐dicarboxyphenylthio) diphenyl ketone dianhydride (3,4′‐PTPKDA), were prepared through multistep reactions. Their structures were determined via Fourier transform infrared, NMR, and elemental analysis. Three series of polyimides (PIs) were prepared from the obtained isomeric dianhydrides and aromatic diamines in N‐methyl‐2‐pyrrolidone (NMP) via the conventional two‐step method. The PIs showed excellent solubility in common organic solvents such as chloroform, N,N‐dimethylacetamide, and NMP. Their glass‐transition temperatures decreased according to the order of PIs on the basis of 3,3′‐PTPKDA, 3,4′‐PTPKDA, and 4,4′‐PTPKDA. The 5% weight loss temperatures (T_5%) of all PIs in nitrogen were observed at 504–519 °C. The rheological properties of isomeric PI resins based on 3,3′‐PTPKDA/4,4′‐oxydianiline/phthalic anhydride showed lower complex viscosity and better melt stability compared with the corresponding isomers from 4,4′‐ and 3,4′‐PTPKDA. In addition, the PI films based on three isomeric dianhydrides and 2,2′‐bis(trifluoromethyl)benzidine had a low moisture absorption of 0.27–0.35%. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

(Azulene‐1,3‐diyl)‐bis(nitronyl nitroxide) and (Azulene‐1,3‐diyl)‐bis(iminonitroxide) and Their Copper Complexes

In contrast to diradicals connected by alternant hydrocarbons, only a few studies on those connected by nonalternant hydrocarbons have been reported. The syntheses, structures, and magnetic properties of azulene‐1,3‐diyl linked bis(nitronyl nitroxide) (NN₂Az) and bis(iminonitroxide) (IN₂Az) diradicals and their Cu(hfac)₂ (hfac=hexafluoroacetylacetonate) complexes were investigated. NN₂Az was shown to have an intramolecular ferromagnetic interaction with J _obs/k _B=+10.0 K (H =−2J S ₁ ⋅S ₂) between (nitronyl nitroxide) spins, whereas IN₂Az was estimated to have a much weaker intramolecular magnetic interaction. The reactions of NN₂Az and IN₂Az with Cu(hfac)₂ gave a 1:2 [{Cu(hfac)₂}₂(NN₂Az)] complex and a 1:1 [Cu(hfac)₂(IN₂Az)] ⋅ C₆H₁₂ complex, respectively. [{Cu(hfac)₂}₂(NN₂Az)] showed strong intramolecular antiferromagnetic interactions (J _1‐Cu‐R/k _B≈−800 K, J _2‐Cu‐R/k _B≈−500 K) between the Cu^II spins and the coordinating NN spins, whereas [Cu(hfac)₂(IN₂Az)] exhibited a ferromagnetic exchange interaction (J _obs‐Cu‐R/k _B=+114 K) between the Cu^II spin and the imino‐coordinated iminonitroxide spin.     

1,1′‐Dimethoxy‐3,3′‐dimethyl‐3,3′‐(hexane‐1,6‐diyl)bis(triazen‐2‐ium‐2‐olate): a nitric oxide donor

The title compound, C₁₀H₂₄N₆O₄, is the most stable type of nitric oxide (NO) donor among the broad category of discrete N‐diazeniumdiolates (NO adducts of nucleophilic small molecule amines). Sitting astride a crystallographic inversion center, the molecule contains a symmetric dimethylhexane‐1,6‐diamine structure bearing two planar O²‐methylated N‐diazeniumdiolate functional groups [N(O)=NOMe]. These two groups are parallel to each other and have the potential to release four molecules of NO. The methylated diazeniumdiolate substituent removes the negative charge from the typical N(O)=NO⁻ group, thereby increasing the stability of the diazeniumdiolate structure. The crystal was nonmerohedrally twinned by a 180° rotation about the real [101] axis. This is the first N‐based bis‐diazeniumdiolate compound with a flexible aliphatic main unit to have its structure analyzed and this work demonstrates the utility of stabilizing the N‐diazeniumdiolate functional group by methylation.     

Electrochemical Reduction of 4,4′‐(2,2,2‐Trichloroethane‐1,1‐diyl)‐ bis(chlorobenzene) (DDT) and 4,4′‐(2,2‐Dichloroethane‐1,1‐diyl)‐ bis(chlorobenzene) (DDD) at Carbon Cathodes in Dimethylformamide

In dimethylformamide containing tetramethylammonium tetrafluoroborate, cyclic voltammograms for reduction of 4,4′‐(2,2,2‐trichloroethane‐1,1‐diyl)bis(chlorobenzene) (DDT) at a glassy carbon cathode exhibit five waves, whereas three waves are observed for the reduction of 4,4′‐(2,2‐dichloroethane‐1,1‐diyl)bis(chlorobenzene) (DDD). Bulk electrolyses of DDT and DDD afford 4,4′‐(ethene‐1,1‐diyl)bis(chlorobenzene) (DDNU) as principal product (67–94%), together with 4,4′‐(2‐chloroethene‐1,1‐diyl)bis(chlorobenzene) (DDMU), 1‐chloro‐4‐styrylbenzene, and traces of both 1,1‐diphenylethane and 4,4′‐(ethane‐1,1‐diyl)bis(chlorobenzene) (DDO). For electrolyses of DDT and DDD, the coulometric n values are essentially 4 and 2, respectively. When DDT is reduced in the presence of a large excess of D₂O, the resulting DDNU and DDMU are almost fully deuterated, indicating that reductive cleavage of the carbon–chlorine bonds of DDT is a two‐electron process that involves carbanion intermediates. A mechanistic scheme is proposed to account for the formation of the various products.     

Hexahydrospiro‐pyrazolo[3,4‐b]pyridine‐4,1′‐pyrrolo[3,2,1‐ij]quinolines Derived from 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione

The tricyclic isatin, 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione ( 1 ), reacts with a combination of an aryl cyanomethyl ketone 8 and a 5‐amino‐1‐arylpyrazole 7 to generate spirocyclic products 9 .     

Synthesis of [3,3′(4H,4′H)‐Bi‐2H‐1,3‐oxazine]‐4,4′‐diones and Their Hydrolysis

The [3,3′(4H,4′H)‐bi‐2H‐1,3‐oxazine]‐4,4′‐diones 3a – 3i were obtained by [2+4] cycloaddition reactions of furan‐2,3‐diones 1a – 1c with aromatic aldazines 2a – 2d (Scheme 1). So, new derivatives of bi‐2H‐1,3‐oxazines and their hydrolysis products, 3,5‐diaryl‐1H‐pyrazoles 4a – 4c (Scheme 3), which are potential biologically active compounds, were synthesized for the first time.     

A dihydroxidotetracopper(II) framework supported by 4,4′‐(adamantane‐1,3‐diyl)bis(1,2,4‐triazole) and benzene‐1,3,5‐tricarboxylate bridges

The new bifunctional ligand 4,4′‐(adamantane‐1,3‐diyl)bis(1,2,4‐triazole) (tr₂ad) and benzene‐1,3,5‐tricarboxylate sustain complementary coordination bridging for the three‐dimensional framework of poly[[bis[μ₃‐4,4′‐(adamantane‐1,3‐diyl)bis(1,2,4‐triazole)‐κ³N¹:N²:N^1′]bis(μ₄‐benzene‐1,3,5‐tricarboxylato‐κ⁴O¹:O^1′:O³:O⁵)di‐μ₃‐hydroxido‐κ⁶O:O:O‐tetracopper(II)] dihydrate], {[Cu₄(C₉H₃O₆)₂(OH)₂(C₁₄H₁₈N₆)₂]·2H₂O}_n. The net node is a centrosymmetric (μ₃‐OH)₂Cu₄ cluster [Cu—O = 1.9525 (14)–2.0770 (15) Å and Cu...Cu = 3.0536 (5) Å] involving two independent copper ions in tetragonal pyramidal CuO₄N and trigonal bipyramidal CuO₃N₂ environments. One carboxylate group of the anion is bridging and the other two are monodentate, leading to the connection of three hydroxide clusters and the generation of neutral coordination layers separated by 9.3583 (5) Å. The interlayer linkage is effected by μ₃‐tr₂ad ligands, with one triazole group N¹:N²‐bridging and the second monodentate [Cu—N = 1.9893 (19), 2.010 (2) and 2.411 (2) Å]. In total, the hydroxide clusters are linked to six close neighbors within the carboxylate layer and to four neighbors via tr₂ad bridges. Hydrogen bonding of solvent water molecules to noncoordinated triazole N atoms and carboxylate groups provides two additional links for the net, which adopts a 12‐connected topology corresponding to hexagonal closest packing. The study also introduces a new type of bis(triazole) ligand, which may find wider applications for supramolecular synthesis.     

1,1′‐Di­acetyl‐3‐hydroxy‐2,2′,3,3′‐tetra­hydro‐3,3′‐bi(1H‐indole)‐2,2′‐dione

In the title compound, C₂₀H₁₆N₂O₅, both of the 1‐acetyl­isatin (1‐acetyl‐1H‐indole‐2,3‐dione) moieties are planar and form a dihedral angle of 74.1 (1)°. Weak intermolecular hydrogen bonds and C—H?π interactions stabilize the packing in the crystal.     

3,3′,5,5′‐Tetramethyl‐4,4′‐bipyrazole–pentafluorophenol (2/3)

In the title compound, 2C₁₀H₁₄N₄·3C₆HF₅O, one of the pentafluorophenol molecules resides on a mirror plane bisecting the O...F axis. The components aggregate by N—H...N, N—H...O and O—H...N hydrogen bonds involving equal disordering of the H atoms into molecular ensembles based on a 2:1 pyrazole–phenol cyclic pattern [O...N = 2.7768 (16) Å and N...N = 2.859 (2) Å], crosslinked into one‐dimensional columns via hydrogen bonding between the outer pyrazole groups and additional pentafluorophenol molecules. The latter yields a 1:1 pyrazole–phenol catemer with alternating strong O—H...N [2.5975 (16) Å] and weaker N—H...O [2.8719 (17) Å] hydrogen bonds. This is the first reported molecular adduct of a pentafluorinated phenol and a nitrogen base, and suggests the utility of highly acidic phenols and pyrazoles for developing hydrogen‐bonded cocrystals.     

2‐Trichloromethylthio‐1H‐iso­indole‐1,3(2H)‐dione (Folpet)

The title compound (C₉H₄Cl₃NO₂S), commonly known as Folpet, belongs to a group of phthalimides which function as fungicides or can be used in the laboratory as sulfurizing agents. The phthalimide moiety is slightly folded with a dihedral angle of 3.5 (4)°. The molecule participates in C—H?O and Cl?Cl intermolecular interactions.     

meso‐2,2′‐Di­phenyl‐3,3′,4,4′‐tetra­hydro‐2,2′‐bi­furan‐5,5′(2H,2′H)‐dione

The crystal structure of the title compound, C₂₀H₁₈O₄, contains a crystallographic inversion center. The C—C bond linking the two halves of the mol­ecule is slightly elongated at 1.577 (3) Å.     

(R)‐(6,6′‐Dihydroxybiphenyl‐2,2′‐diyl)bis(diphenylphosphine oxide) methanol solvate

The title compound, C₃₆H₂₈O₄P₂·CH₄O, was synthesized directly from the methoxy analogue. The crystal structure shows that one OH group interacts with an O atom of a phosphine oxide group in an adjacent mol­ecule, while the other OH group complexes with the methanol solvent molecule via intermolecular hydrogen bonds. An O atom of one phosphine oxide group interacts with the hydroxy H atom of methanol via a hydrogen bond. There are intra‐ and intermolecular π–π interactions between the phenyl rings. All these interactions result in the formation of supramolecular chiral parallelogram channels via self‐assembly.     

The Convenient Synthesis of 11‐Methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione Derivatives

The 2‐arylidene‐3‐oxobutanenitrile derivatives 2 were prepared by the Knoevenagel condensation between aldehydes and 3‐oxobutanenitrile 1 , which was obtained by acid hydrolysis of β‐aminocrotononitrile. 3‐Acetyl‐2‐amino‐4H‐chromen‐5(6H)‐one derivatives 3 were synthesized by reaction of 2‐arylidene‐3‐oxobutanenitrile 2 and 5‐substituted‐1,3‐cyclohexanedione in ethylene glycol. The 11‐methyl‐3,8‐disubstituted‐12‐aryl‐3,4,7,8,9,12‐hexahydro‐1H‐chromeno[2,3‐b]quinoline‐1,10(2H)‐dione derivatives 4 were obtained by Friedländer reaction of compounds 3 with 5‐substituted‐1,3‐cyclohexanedione, using p‐toluenesulfonic acid monohydrate as catalyst. The structures of all novel compounds were characterized by elemental analysis, IR, MS, and ¹H NMR spectra. The crystal and molecular structure of compound 4f has been determined by single crystal XRD analysis.     

rac‐ and meso‐3,3′‐Bis(3,5‐di­methyl­phenyl)‐3H,3′H‐2,2′‐biindenyl­idene‐1,1′(2H,2′H)‐dione

In the rac isomer of the title compound, C₃₄H₂₈O₂, the two C—Ph_{di­methyl­phenyl} bond axes make an angle of 58.7 (1)°. There is no short contact between the two 3,5‐di­methyl­phenyl rings, although the dihedral angle between them is 4.93 (7)°. The meso isomer has a center of symmetry at the middle of the C=C bond, and the two C—Ph_{di­methyl­phenyl} bond axes are antiparallel to one another.     

1,4‐Phenylenebis(methylene) bis(9H‐carbazole‐9‐carbodithioate)

The molecules of the title compound, C₃₄H₂₄N₂S₄, lie across centres of inversion in the space group P2₁/n. The spacer unit linking the benzene rings and carbazole units is effectively planar, while the carbazole unit itself is slightly folded. Molecules are linked into sheets by a single C—H...π(arene) hydrogen bond and the hydrogen‐bonded sheets are themselves linked into a three‐dimensional framework structure by a single π–π stacking interaction.     

Synthesis of 2‐Chirally Substituted 3,3′‐Biquinazoline‐4,4′‐diones

A facile route for the synthesis of 2‐substituted biquinazolinones incorporating a chiral center into one of their lateral appendage, via condensation of 4H‐3,1‐benzoxazin‐4‐one with 3‐amino‐2S‐substituted‐quinazolin‐4‐ones, is described. The methodology is straightforward and does not require chromatographic purification at any stage. The products are obtained in good yields as mixture of diastereoisomers, which can be enriched with the major diastereoisomer by simple recrystallization. The functional groups in the lateral chain can be easily modified allowing the synthesis of a variety of 3,3′‐biquinazoline‐4,4′‐diones. The synthesis of symmetrically 2,2′ chirally disubstituted biquinazolinones via acylation/dehydration sequence of bisanthraniloyl hydrazine is also described.