Solid‐Phase Approach for the Synthesis of 2‐Amido‐1,3,4‐oxadiazoles

A new solid‐phase approach for the synthesis of 2‐amido‐1,3,4‐oxadiazoles has been developed. In this synthesis, hydroxypentyl JandaJel polymer support was treated with excess of oxalyl chloride to give resin‐bound 2‐chloro‐2‐oxoacetate, and this intermediate was then coupled with different hydrazides to give resin‐bound 2‐(N′‐acylhydrazinyl)‐2‐oxoacetate. Intramolecular dehydrative cyclization of resulting resin‐bound linear precursor followed by direct amidation using aluminum amide reagent provided 5‐substituted 1,3,4‐oxadiazoles as 2‐carboxamides. To explore the scope of this reaction sequence, we synthesized a small set of library using a combination of hydrazides and amines, and the desired products were obtained in good to high yields.     

Nafion®‐supported oxovanadium‐catalyzed hydrophosphonylation of aldehydes under solventless conditions

A Nafion® resin‐supported oxovanadium(IV) catalyst was readily prepared via ion‐exchange method. This solid vanadyl perfluorinated sulfonate catalyst was used as an efficient and recoverable catalyst for the hydrophosphonylation of various aldehydes under solventless conditions at room temperature. The catalyst could be recovered by simple filtration and reused without a significant loss of activity. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis and tuberculostatic activity of novel N′‐methyl‐4‐(pyrrolidin‐1‐yl)picolinohydrazide and N′‐methylpyrimidine‐2‐carbohydrazide derivatives

The synthesis of N′‐methyl‐4‐(pyrrolidin‐1‐yl)picolinohydrazide and N′‐methyl‐pyrimidine‐2‐carbohydrazide derivatives ( 5a and 5b ) was carried out. These compounds were used as starting materials to obtain methyl N′‐methylhydrazinecarbodithioates 6a and 6b , which, on reaction with either triethylamine or hydrazine, gave corresponding 1,3,4‐oxadiazioles 7a and 7b or 1,2,4‐triazoles 9a and 9b with the free NH₂ group at the N‐4 position, respectively. Compounds 8a – e , particularly containing cyclic amines at N‐4 of the 1,2,4‐triazole ring, were also obtained. Synthesized compounds were tested in vitro for their activity against Mycobacterium tuberculosis. The structure–activity relationship analysis for obtained compounds was done. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:223–230, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21008     

固相合成甲胺基阿维菌素苯甲酸盐

To implement the solid phase synthesis of 4““-epi-methylamino-4““-deoxyavermecfin B1 benzoate, tert-butyldimethylsilylchloride was chosen for the first solution synthesis. Then a novel silyl chloride resin 1, achieved from hydroxymethyl polystyrene resin and dimethyldichlorosilane, was used successfully for the attachment of avermectin B1 2. Through oxidation, amination formation, cleavage, and benzoate formation, resin bounded avermectin B1 9 gave 4““-epi-methylamino-4““-deoxyavermectin B1 benzoate 3.     

An approach to 1,2‐dihydro‐1,4,2‐ benzodiazaphosphinines

A convenient approach to 1,2‐dihydro‐1,4,2‐benzodiazaphosphinines was proposed. The readily available 2‐trichloromethyl‐1,3‐dihydrobenzo[1,3,2]diazaphosphole‐2‐oxide (sulfide or selenide) was found to undergo a rearrangement into the targeted benzodiazaphosphinines by the action of dimethylamide lithium. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:309–313, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21018     

Synthesis and electrophilic cyclization reactions of diphenyl 3‐methylhexa‐ 1,3,4‐trien‐3‐yl phosphine oxide

Diphenyl 3‐methylhexa‐1,3,4‐trien‐3‐yl phosphine oxide can be readily prepared via an atom‐economical 2,3‐sigmatropic rearrangement of the mediated alkenynyl phosphinite formed in situ by a reaction of 2‐methylhex‐5‐en‐3‐yn‐2‐ol with diphenylchlorophosphine. Electrophilic cyclization reactions of prepared 1‐vinylallenyl phosphine oxide were investigated as it was established that the reactions proceeded with formation of heterocyclic compounds with participation of the allenic and/or 1,3‐dienic part of the vinylallenic system with neighboring group participation of the phosphoryl and/or vinylic group. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:345–351, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21023     

Self‐organization of liquid crystalline 3,4,5‐tris[(11‐methacryloyl‐undecyl‐1‐oxy)‐4‐benzyloxy]benzoates in low‐shrinkage methacrylate mixtures

Crystallization and supramolecular aggregation of 3,4,5‐tris[(11‐methacryloyl‐undecyl‐1‐oxy)‐4‐benzyloxy]benzoate (1), 2‐methyl‐(1,4,7,10,13‐pentaoxabenzocyclopentadecane)‐3,4,5‐tris[(11‐methacryloyl‐undecyl‐1‐oxy)‐4‐benzoxyloxy]benzoate (2) and its 1 : 1 sodium triflate complex (2a) are described in solutions of methacrylate monomers. Formation of gels and subsequent polymerization yielded “supramolecular interpenetrating networks” consisting of an isotropic polymethacrylate resin, percolated by supramolecular aggregates of the solute, which are covalently connected to the resin phase. Compound 1 formed whisker‐type crystals, while 2 self‐organizes in networks of elongated supramolecular fibrils with diameters corresponding to the twofold length of one molecule. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 631–640, 2000     

ε‐Caprolactone polymerization under air by the biocatalyst: Magnesium 2,6‐di‐tert‐butyl‐4‐methylphenoxide

This study investigated the synthesis of the biocatalyst, magnesium 2,6‐di‐tert‐butyl‐4‐methylphenoxide (Mg(BHT)₂) complex, and the ring‐opening polymerization (ROP) of ε‐caprolactone (CL). The complex demonstrates high catalytic activity and controllable of molecular weight for the ROP of CL in tetrahydrofuran at room temperature, even when polymerization was performed under air. Before this study, the polymerization of CL had never been performed using a magnesium catalyst under air at room temperature. Various forms of alcohols with different purposes were also used as initiators with Mg(BHT)₂. The results show that the magnesium complex acts as a perfect catalyst because of its high catalytic activity and control ability without any cytotoxicity in the polymerization of CL, making it suitable for biomedical applications. In addition, nanoparticle formation, cytotoxicity, and phototoxicity of tri‐2‐hydroxyethyl ester [Ce6‐(CH₂CH₂OPCL)₃] were also studied in this article and Ce6‐(CH₂CH₂OPCL)₃ formed nanoparticle can act as a nanophotosensitizer for photodynamic therapy. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis of Bis(imidazole‐2‐thion‐4‐yl)phosphanes

Novel bis(imidazole‐2‐thion‐4‐yl)‐ phosphanes ( 2a–d ) were synthesized via lithiation of the precursor imidazole‐2‐thiones followed by the phosphanylation reaction. Oxidation of bis(imidazole‐2‐thion‐4‐yl)phosphane 2b–d with elemental sulfur and selenium led selectively and in good yields to the P‐thio ( 3b–d ) and P‐seleno ( 4c ) derivatives of bis(imidazole‐2‐thion‐4‐yl)phosphanes, respectively. The treatment of 2a,c with phosphorus trichloride gives the corresponding P‐chloro derivatives 5a,c . These compounds were unambiguously characterized by elemental analyses, spectroscopic and spectrometric methods, in addition by single‐crystal X‐ray structure analysis in the case of 2d . © 2012 Wiley Periodicals, Inc. Heteroatom Chem 00:1–7, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21043     

Synthesis and antiosteoclast activity of Di(1‐oxo/thioxoperhydro‐1λ5‐[1,3,2] diazaphospholo [1,5‐a]pyridine‐1‐yl) (4‐substituted phenyl) boronates

A new family of di(1‐oxo/thioxoper‐hydro‐1λ⁵‐[1,3,2]diazaphospholo[1,5‐a]pyridine‐1‐yl)(4‐substituted phenyl) boronates ( 4a – j ) has been synthesized in a two‐step process. A reaction of (±)‐piperidin‐2‐yl‐methanamine ( 1 ) phosphoryl/phosphorothioyl chloride in the presence of triethylamine in dry tetrahydrofuran formed the intermediate monochloride ( 2 ), which on condensation with p‐substituted phenylboronic acids ( 3a – j ) afforded the titled compounds ( 4a – j ). They were characterized by elemental, IR, ¹H, ¹³C, ³¹P NMR, and mass spectral analyses. All these compounds showed moderate to high antiosteoclast and osteoblast activity. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:247–253, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21010     

2,3‐bis(5‐Hexylthiophen‐2‐yl)‐6,7‐bis(octyloxy)‐5,8‐di(thiophen‐2‐yl) quinoxaline: A good construction block with adjustable role in the donor‐π‐acceptor system for bulk‐heterojunction solar cells

Three 2,3‐bis(5‐hexylthiophen‐2‐yl)‐6,7‐bis(octyloxy)‐5,8‐di(thiophen‐2‐yl)‐quinoxaline ( BTTQ )‐based conjugated polymers, namely, PF‐BTTQ ( P1 ), PP‐BTTQ ( P2 ), and PDCP‐BTTQ ( P3 ), were successfully synthesized for efficient polymer solar cells (PSCs) with electron‐rich units of fluorene and dialkoxybenzene and electron‐deficient unit dicyanobenzene, respectively. All the polymers exhibited good solubility in common organic solvents and good thermal stability. Their deep‐lying HOMO energy levels enabled them good stability in the air and the relatively low HOMO energy level assured a higher open circuit potential when used in PSCs. Bulk‐heterojunction solar cells were fabricated using these copolymers blended with a fullerene derivative as an acceptor. All of them exhibited promising performance, and the best device performance with power conversion efficiency up to 3.30% was achieved under one sun of AM 1.5 solar simulator illumination (100 mW/cm²). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Reaction of 2‐Alkoxy‐4,5‐diphenyl‐1,3‐oxazin‐6‐one with different alcohols and elucidation of the products

Reaction of 2‐methoxy‐4,5‐diphenyl‐1,3‐oxazin‐6‐one 1a with methanol was studied, and the product of the reaction was determined by spectroscopic data and X‐ray analysis. In addition, a series of (Z)‐alkyl 3‐(alkoxycarbonylamino)‐2,3‐diphenylacrylate 4 was synthesized and characterized. J. Heterocyclic Chem., (2012).     

Synthesis of 10‐amino‐9‐aryl‐2,3,4,5,6,7,9,10‐octahydroacridine‐1,8‐dione derivatives

A series of novel 10‐amino‐9‐aryl‐2,3,4,5,6,7,9,10‐octahydroacridine‐1,8‐dione derivatives 4 were synthesized by hydrazine or phenylhydrazine and 9‐aryl‐1,8‐dioxo‐2,3,4,5,6,7,9‐heptahydroxanthene derivatives 3 , which were prepared by 5‐substituted‐1,3‐cyclohexanedione 1 and aromatic aldehydes 2 in the presence of concentrated H₂SO₄ as a catalyst in water. The structures of all compounds were characterized by IR, MS, ¹H‐NMR, and elemental analysis, and the title compounds possess good fluorescence properties. J. Heterocyclic Chem., (2012).     

Analysis of dammar resin with MALDI‐FT‐ICR‐MS and APCI‐FT‐ICR‐MS

Comprehensive analysis of high‐resolution mass spectra of aged natural dammar resin obtained with Fourier transform ion cyclotron resonance mass spectrometer (FT‐ICR‐MS) using matrix‐assisted laser desorption/ionization (MALDI) and atmospheric pressure chemical ionization (APCI) is presented. Dammar resin is one of the most important components of painting varnishes. Dammar resin is a terpenoid resin (dominated by triterpenoids) with intrinsically very complex composition. This complexity further increases with aging. Ten different solvents and two‐component solvent mixtures were tested for sample preparation. The most suitable solvent mixtures for the MALDI‐FT‐ICR‐MS analysis were dichloromethane‐acetone and dichloromethane‐ethanol. The obtained MALDI‐FTMS mass spectrum contains nine clusters of peaks in the m/z range of 420–2200, and the obtained APCI‐FTMS mass spectrum contains three clusters of peaks in the m/z range of 380–910. The peaks in the clusters correspond to the oxygenated derivatives of terpenoids differing by the number of C₁₅H₂₄ units. The clusters, in turn, are composed of subclusters differing by the number of oxygen atoms in the molecules. Thorough analysis and identification of the components (or groups of components) by their accurate m/z ratios was carried out, and molecular formulas (elemental compositions) of all major peaks in the MALDI‐FTMS and APCI‐FTMS spectra were identified (and groups of possible isomeric compounds were proposed). In the MALDI‐FTMS and APCI‐FTMS mass spectrum, besides the oxidized C₃₀, triterpenoids also peaks corresponding to C₂₉ and C₃₁ derivatives of triterpenoids (demethylated and methylated, correspondingly) were detected. MALDI and APCI are complementary ionization sources for the analysis of natural dammar resin. In the MALDI source, preferably polar (extensively oxidized) components of the resin are ionized (mostly as Na⁺ adducts), whereas in the APCI source, preferably nonpolar (hydrocarbon and slightly oxidized) compounds are ionized (by protonation). Either of the two ionization methods, when used alone, gives an incomplete picture of the dammar resin composition. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis of some new 1‐acyl‐5‐aryl‐3‐(5‐methyl‐1‐p‐tolyl‐1H‐1,2,3‐triazol‐4‐yl)‐4,5‐dihydro‐1H‐pyrazole

Some new compounds (E)‐3‐aryl‐1‐(5‐methyl‐1‐p‐tolyl‐1H‐1,2,3‐triazol‐4‐yl)‐prop‐2‐en‐1‐ones 5a–e were prepared by 1‐(5‐methyl‐1‐p‐tolyl‐1H‐1,2,3‐triazol‐4‐yl)‐ethanone and various aromatic aldehydes. Then one pot reaction was happened by compounds 5a–e with hydrazine hydrate in acetic acid or propionic acid, respectively, to give the title compounds 1acyl‐5‐aryl‐3‐(5‐methyl‐1‐p‐tolyl‐1H‐1,2,3‐triazol‐4‐yl)‐4,5‐dihydro‐1H‐pyrazoles 6a–i . All structures were established by MS, IR, CHN, ¹H‐NMR and ¹³C‐NMR spectral data. J. Heterocyclic Chem., (2012).     

Synthesis and antimicrobial evaluation of new 1‐{[4‐(4‐Halogenophenyl)‐4H‐1,2,4‐ triazol‐3‐yl]sulfanyl}acetyl‐4‐substituted thiosemicarbazides and products of their cyclization

By the reaction of hydrazides of 4‐(4‐halogenophenyl)‐4H‐1,2,4‐triazol‐3‐yl‐sulfanyl acetic acid with isothiocyanate, 1‐acyl‐4‐substituted thiosemicarbazide derivatives ( 7–19 ) were obtained. The cyclization of compounds ( 7–19 ) in the presence of 2% NaOH led to the formation of compounds ( 20–26 ) containing two 1,2,4‐triazole rings connected by a methylenesulfanyl group. The new compounds were tested for their in vitro antimicrobial activity. Some of the tested compounds ( 9, 12, 18, 21, 22 ) showed activity against the reference strains of Gram‐positive bacteria with the MIC (minimal inhibitory concentration) = 125 to >1000 μg/mL. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:117–121, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20758     

Synthetic studies with 3‐Oxo‐N‐[4‐(3‐oxo‐ 3‐phenylpropionylamino)‐phenyl]‐3‐phenylpropionamide

3‐Oxo‐N‐[4‐(3‐oxo‐3‐phenylpropionylamino)‐phenyl]‐3‐phenylpropionamide 1 and its derivative 2‐benzoyl‐N‐[4‐(2‐benzoyl‐3‐(dimethylamino‐acryloylamino)‐phenyl]‐3‐dimethylaminoacrylamide 12 are used for the synthesis of the hitherto not known bis‐heterocyclic amine and bis‐heterocyclic carboxamide derivatives. Plausible mechanisms are discussed for the formation of the new compounds. J. Heterocyclic Chem., (2012).     

Synthesis of 1‐acetoxy‐2‐aminoakenes via condensation of amino with carbonyl and CC acetoxylation

1‐Acetoxy‐2‐aminoakenes were synthesized through an effective synthetic route using acid as the catalyst and (diacetoxyiodo)benzene as the oxidant, which is also a novel strategy for the formation of two C‐heteroatom bonds in the same reaction. In addition, it is a practical protocol with high regioselectivity, atom efficiency, and good substrate scope. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 23:290–294, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.21016     

Palladium‐catalyzed cyclization of β‐bromo‐α,β‐unsaturated ketones with arylhydrazines leading to 3‐substituted 1‐aryl‐1 H‐pyrazoles

β‐Bromo‐α,β‐unsaturated ketones are condensed with arylhydrazines to form hydrazones, which are in situ intramolecularly cyclized into 3‐substituted 1‐aryl‐1 H‐pyrazoles under a catalytic system of Pd(OAc)₂/1,3‐bis(diphenylhosphino)propane (dppp)/NaO^tBu. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis of 3‐(3,5‐dinitropyrazol‐4‐yl)‐4‐nitrofurazan and its salts

The annulation reaction of vinamidinium salt containing nitrofurazanyl moiety at the β‐position gives access to the corresponding pyrazole. At nitration, two nitro groups were installed to the pyrazole ring. The synthesized 3‐(3,5‐dinitropyrazol‐4‐yl)‐4‐nitrofurazan 13 is strong NH acid and a new family energetic salts was prepared by direct neutralization with high nitrogen bases. Compound 13 crystallizes in the monoclinic space group P2₁/c, and charaterized by high density of 1.979 g/cm³ (at 100 K). J. Heterocyclic Chem., (2012).