The Reaction Studies of α‐Chloroformylarylhydrazines with Thiols,Thioureas and α‐Cyclodiketones

The reactions of α‐chloroformylarylhydrazines 1 with various types of mercaptan, thiourea and α‐cyclodiketone have been studied intensively. 1‐Arylhydrazinecarbothioates 2 were obtained via thioesterization when α‐chloroformylarylhydrazines reacted with thiols. On the other hand, compounds 3 were obtained when α‐chloroformylarylhydrazines reacted with thio‐containing heterocyclic compounds, which suggested a totally different mechanism in these types of reactions. Further studies on the reaction of α‐chloroformylarylhydrazines 1 with thiourea compounds confirmed a novel cyclization and de‐cyclization mechanism, which led to give 2‐arylhydrazinecarboximidamides 5 and 1,3,4‐thiadiazolin‐5‐ones 6 . In addition, various 1,3,4‐oxadiazines 9 were obtained by reacting α‐chloroformylarylhydrazines with α‐cyclodiketones, showing ring cyclization was involved in this type of reaction.     

Conversion of bis(o‐nitrophenyl)diselenides to heterocycles containing selenium and nitrogen with the aid of samarium diiodide

Treatment of bis(o‐nitrophenyl)diselenides with SmI₂ led to simultaneous reduction of nitro groups and reductive cleavage of Se Se bonds as well as to the formation of the intermediates 2 . The intermediates 2 were “living” double‐anions formed in situ, and reacted readily with ω‐bromoketones and α‐bromocarboxylic acid derivatives to afford the desired 2H‐1,4‐benzoselenazines and 2H‐1,4‐benzoselenazin‐3(4H)‐ones, respectively, in moderate to high yields and under mild conditions. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:302–306, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10034     

Synthesis and polymerization of phosphorus‐containing acrylates

Novel phosphorus‐containing acrylate monomers were synthesized by two different routes. The first involved the reaction of ethyl α‐chloromethyl acrylate and t‐butyl α‐bromomethyl acrylate with diethylphosphonoacetic acid. The monomers were bulk‐ and solution‐polymerized at 56–64 °C with 2,2′‐azobisisobutyronitrile. The ethyl ester monomer showed a high crosslinking tendency under these conditions. The selective hydrolysis of the ethyl ester phosphonic ester compound was carried out with trimethylsilyl bromide, producing a phosphonic acid monomer. In the second route, ethyl α‐hydroxymethyl acrylate and t‐butyl α‐hydroxymethyl acrylate were reacted with diethylchlorophosphate. The bulk homopolymerization and copolymerization of these monomers with methyl methacrylate and 2,2′‐azobisisobutyronitrile gave soluble polymers. The attempted hydrolysis of the monomers was unsuccessful because of the loss of the diethylphosphate group. The relative reactivities of the monomers in the photopolymerizations were also compared. The ethyl α‐hydroxymethyl acrylate/diethylphosphonic acid monomer showed higher reactivity than the other monomers, which may explain the crosslinking during the polymerization of this monomer. The reactivities of other derivatives were similar, but the rates of polymerization were slow in comparison with those of methyl methacrylate. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3221–3231, 2002     

Synthesis of new 2,2′‐disubstituted 5,5′‐dimethyl‐4,4′‐bitriazoles and 2‐(4‐Triazolyl)quinoxalines

Thermal rearrangement of 3‐acylisoxazole arylhydrazones allowed facile preparation of 2H‐1,2,3‐triazoles which were firstly reacted with isoamyl nitrite and then with an opportune arylhydrazine to produce the corresponding α‐hydroxyiminohydrazones 8a‐h . The reaction of compounds 8a‐h with phosphorus pentachloride afforded the desired 4,4′‐bitriazoles 1a‐h . The α‐hydroxyiminoketone derivative 7 or the α‐diketone 14 reacted easily with 1,2‐phenylenediamine to afford 1,2,3‐triazoles 2a‐c bearing the quinoxaline moiety at position 4. Improved yields of the quinoxalines 2a‐c were obtained when 1,2‐phenylenediamine was reacted with the dioxime 15.     

Analysis of α‐acyloxyhydroperoxy aldehydes with electrospray ionization–tandem mass spectrometry (ESI‐MSn)

A series of α‐acyloxyhydroperoxy aldehydes was analyzed with direct infusion electrospray ionization tandem mass spectrometry (ESI/MSⁿ) as well as liquid chromatography coupled with the mass spectrometry (LC/MS). Standards of α‐acyloxyhydroperoxy aldehydes were prepared by liquid‐phase ozonolysis of cyclohexene in the presence of carboxylic acids. Stabilized Criegee intermediate (SCI), a by‐product of the ozone attack on the cyclohexene double bond, reacted with the selected carboxylic acids (SCI scavengers) leading to the formation of α‐acyloxyhydroperoxy aldehydes. Ionization conditions were optimized. [M + H]⁺ ions were not formed in ESI; consequently, α‐acyloxyhydroperoxy aldehydes were identified as their ammonia adducts for the first time. On the other hand, atmospheric‐pressure chemical ionization has led to decomposition of the compounds of interest. Analysis of the mass spectra (MS² and MS³) of the [M + NH₄]⁺ ions allowed recognizing the fragmentation pathways, common for all of the compounds under study. In order to get detailed insights into the fragmentation mechanism, a number of isotopically labeled analogs were also studied. To confirm that the fragmentation mechanism allows predicting the mass spectrum of different α‐acyloxyhydroperoxy aldehydes, ozonolysis of α‐pinene, a very important secondary organic aerosol precursor, was carried out. Spectra of the two ammonium cationized α‐acyloxyhydroperoxy aldehydes prepared with α‐pinene, cis‐pinonic acid as well as pinic acid were predicted very accurately. Possible applications of the method developed for the analysis of α‐acyloxyhydroperoxy aldehydes in SOA samples, as well as other compounds containing hydroperoxide moiety are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

The Syntheses of 4‐Arylamino‐1,2,3‐Triazoles and Stable 6‐Sydnonyl Verdazyls from Sydnone Derivatives and Their Fragments

α‐Chloroformylarylhydrazones 1 and α‐chloroformylarylhydrazones of sydnonecarbaldehydes 3 have been prepared by a new synthetic route: α‐chloroformylarylhydrazines hydrochlorides 2 reacted with corresponding carbonyl compounds. Reactions of compounds 3 with various hydrazines to give 6‐sydnonyl‐1,2,4,5‐tetrazinan‐3‐ones 7 and/or carbazones 8 were also investigated. By oxidization with lead dioxide, compounds 7 were trans formed to stable 6‐sydnonyl‐3,4‐dihydro‐3‐oxo‐1,2,4,5‐tetrazin‐1(2H)‐yl radical derivatives 9 (sydnonyl verdazyls). Furthermore, sydnonecarbaldehydes arylhydrazones 5 through acidic conditions could be transferred to 4‐arylamino‐1,2,3‐triazoles 6 which were also obtained by means of acidic decompositions of 4‐formylsydnones 10 .     

Synthesis and characterization of copolyperoxides of indene with styrene, α‐methylstyrene,and α‐phenylstyrene

The oxidative copolymerization of indene with styrene, α‐methylstyrene, and α‐phenylstyrene is investigated. Copolyperoxides of different compositions have been synthesized by the free‐radical‐initiated oxidative copolymerization of indene with vinyl monomers. The compositions of the copolyperoxides obtained from the ¹H and ¹³C NMR spectra have been used to determine the reactivity ratios of the monomers. The reactivity ratios indicate that indene forms an ideal copolyperoxide with styrene and α‐methylstyrene and alternating copolyperoxides with α‐phenylstyrene. Thermal degradation studies via differential scanning calorimetry and electron‐impact mass spectroscopy support the alternating peroxide units in the copolyperoxide chain. The activation energy for thermal degradation suggests that the degradation is dependent on the dissociation of the peroxide (? O? O? ) bonds in the backbone of the copolyperoxide chain. Their flexibility has been examined in terms of the glass‐transition temperature. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2004–2017, 2002     

Synthesis of some new benzofuran‐based thiophene, 1,3‐oxathiole and 1,3,4‐oxa(thia)diazole derivatives

Treatment of 3‐(3‐methylbenzofuran‐2‐yl)‐3‐oxopropanenitrile ( 1 ) with phenyl isothiocyanate afforded the thioacetanilide derivative 3 , which when reacted with α‐haloketones, α‐halodiketones, and hydrazonoyl chlorides gives thiophene, 1,3‐oxathiole, and 1,3,4‐thiadiazole derivatives 6a,b, 10a,b and 14a–g , respectively. Treatment of 3‐methyl‐2‐benzofurancarboxylic acid hydrazide ( 15 ) with benzaldehyde followed by bromine afforded the 1,3,4‐oxadiazole derivative 18 . Treatment of the acid hydrazide 15 with phenyl isothiocyanate gave the thiosemicarbazide 20 . Compound 20 could be converted into 1,3,4‐oxadiazole, 1,2,4‐triazole‐3‐thione, and 1,3,4‐thiadiazole derivatives 21, 22 , and 23 , respectively. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:294–300, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20298     

Unexpected conversions of selected heteroorganic compounds

A few unexpected conversions of selected heteroorganic compounds are described, including the formation of N‐sulfonyl sulfenamide derivatives and the mixed phosphinyl‐sulfenyl anhydrides in the reactions of sulfinyl chlorides with α‐phenylethylamine or t‐butyl‐phenylphosphine oxide, respectively. Unexpected reactions of the ortho hydroxyalkyl‐substituted diaryl sulfoxides and hypervalent sulfur and selenium derivatives, induced by triphenylphosphine, are also presented. Attempts to rationalize the observed reaction courses are briefly discussed. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:437–442, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10077     

An activated catalyst RhH(PPh3)4‐dppe‐ Me2S2 for α‐methylthiolaton of α‐phenyl ketones

In the presence of catalytic amounts of RhH(PPh₃)₄, 1,2‐bis(diphenylphosphino)ethane (dppe), and dimethyl disulfide, cyclic and acyclic α‐phenyl ketones reacted with p‐cyano‐α‐methylthioa‐ cetophenone giving α‐methylthio‐α‐phenylketones. The activated catalyst containing dimethyl disulfide was effective for the α‐methylthiolation reaction of these less reactive substrates. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:18–23, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20650     

Utilization of α‐halocarbonyl compounds in the synthesis of thiazole,thiadiazole, and thiophene derivatives

The behavior of ethyl 2‐phenylthiocarb‐ amoyl acetate 1 toward a variety of several α‐halo‐ carbonyl compounds was investigated. Thus, reaction of 1 with α‐bromoketones, hydrazonoyl bromides, and 2‐chloro‐N‐arylacetamides afforded the corresponding dihydrothiazole, 1,3,4‐thiadiazole, and thiophene derivatives, respectively. The synthesis of thiazolidin‐4‐one 11 , thiazolidin‐5‐one 12 , and some azo derivatives of thiazolidin‐5‐one were described. 5‐Arylazothiazoles 17 and 19 were synthesized by condensation of hydrazonoyl bromides 3 with different thiourea derivatives. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:299–305, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20206     

Linear functionalized polyethylene prepared with highly active neutral Ni(II) complexes

Neutral Ni(II) salicylaldimine catalysts (pendant ligand = NCMe or PPh₃) were used to copolymerize ethylene with monomers containing esters, alcohols, anhydrides, and amides and yielded linear functionalized polyethylene in a single step. α‐Olefins and polycyclic olefin comonomers carrying functionality were directly incorporated into the polyethylene backbone by the catalysts without any cocatalyst, catalyst initiator, or other disturber compounds. The degree of comonomer incorporation was related to the monomer structure: tricyclononenes > norbornenes > α‐olefins. A wide range of comonomer incorporation, up to 30 mol %, was achieved while a linear polyethylene structure was maintained under mild conditions (40 °C, 100 psi ethylene). Results from the characterization of the copolymers by solution and solid‐state NMR techniques, thermal analysis, and molecular weight demonstrated that the materials contained a relatively pure microstructure for a functionalized polyethylene that was prepared in one step with no catalyst additive. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2842–2854, 2002     

Practical synthesis of thiirene 1‐oxides that possess two bulky alkyl substituents

Acetylenes that possess two bulky alkyl substituents reacted with sulfur dichloride to furnish the corresponding 2,3‐dialkyl‐2,3‐dichlorothiiranes ( 5 ) nearly quantitatively. The alkaline hydrolysis of 5 afforded 2,3‐dialkylthiirene 1‐oxides ( 10 ) in high yields. These two reactions could be successively carried out in one flask, and 2,3‐di‐tert‐butyl‐, 2,3‐di‐(1‐adamantyl)‐, and 2‐(1‐adamantyl)‐3‐tert‐butylthiirene 1‐oxides ( 10a–c ) were obtained in 70, 80, and 90% yields, respectively, based on the starting acetylenes, thus providing the most convenient synthesis of thiirene 1‐oxides. Disulfur dichloride also reacted with acetylenes to give 5 in good yields with the elimination of one sulfur atom. Although the alkaline hydrolysis of 5 provided 10 exclusively, acid hydrolysis gave a mixture of α‐oxothioketone 9 and thiirene 1‐oxide 10 in modest yields. All thiirene 1‐oxides 10a–c isomerized to produce α‐oxothioketones 9 in high yields when heated in boiling toluene. Reactions of a bis‐acetylene ( 18 ) with disulfur dichloride and with sulfur dichloride gave a dihydropentathiepin ( 19 ) in high yields. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:424–430, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10070     

Syntheses,spectral property,and antimicrobial activities of 6‐α‐amino dibenzo [d,f][1,3,2]dioxaphosphepin 6‐oxides

Diethyl α‐aminophosphonates ( 4 ) were prepared in excellent yield from three‐component reaction of aldehydes ( 1 ), amines ( 2 ), and triethylphosphite ( 3 ) under solvent‐free conditions in the presence of ceric ammonium nitrate (CAN) and were reacted with 2,2′‐dihydroxybiphenyl ( 5 ) using p‐toluene sulfonic acid monohydrate (PTSA) as a catalyst to obtain 6‐α‐aminodibenzo[d f][1,3,2]dioxaphosphepin 6‐oxides ( 6 ) in good yield. It is a first report on the cyclizations of 4 with 5 . An antimicrobial activity of numbers of 6 is evaluated. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:2–8, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20244     

Bivariate distribution in copolymers: A new model

A new model for the bivariate distribution of chain sizes and composition in copolymers is presented. The model combines the sum of a two‐bivariate distribution, and it replaces the previous model that consists of a single entity. The compositional distribution histogram was obtained by summation of the sections of the bivariate distribution that belong to a narrow compositional range. The predictions of the model were compared with mass spectrometric data relative to a block copolymer sample containing structural units of pivalolactone and 3‐hydroxybutyrate with some literature data, namely, mass spectrometric data concerning a random copolymer sample reacted at high conversion containing units of styrene and methyl methacrylate as well as a block copolymer sample containing units of α‐methyl styrene and methyl methacrylate. The new model gives better results than the previous model because it fits better with the experimental compositional distribution histogram of the copolymer samples. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2442–2448, 2002     

Rationalization of the stereochemistry of an addition of dialkyl phosphites to certain chiral aldimines: The experimental and theoretical approach

The absolute configuration of an α‐P stereogenic center in two diastereomeric O,O‐dialkyl α‐aminophosphonates ( 3 ), arising from an induced 1,3‐asymmetric phosphite addition to the CN bond of furfural‐derived Schiff bases ( 1 ), was established from single product ¹H NMR data. Such spectra were interpreted with anisotropic shielding in relation to the AM1 and MNDO/d structures of 3 ; the former ones turned out to be closer to the obtained experimental results (¹H NMR spectra of 3 , crystallographic database study). Since favored 3‐21G geometries of starting imines 1 were modeled as well, it was inferred that a stereochemical outcome of this reaction is governed by Cram selectivity. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:120–125, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10005     

Alkylamines‐intercalated α‐zirconium phosphate as latent thermal anionic initiators

The reaction of glycidyl phenyl ether (GPE) with 1‐aminoalkanes‐intercalated α‐zirconium phosphate (α‐ZrP·1‐aminoalkane): 1‐aminoalkanes 1‐aminopropane (α‐ZrP·Pr), 1‐aminobutane (α‐ZrP·Bu), 1‐aminooctane (α‐ZrP·Oct), and 1‐aminohexadecane (α‐ZrP·Hed) was carried out at varying temperatures for 1 h periods. Reaction progress was not observed until the reactants were heated to 80 °C or above. On increasing the temperature, the conversion factors increased such that, at 140 °C, conversions of 62% (α‐ZrP·Pr), 60% (α‐ZrP·Bu), 67% (α‐ZrP·Oct), and 64% (α‐ZrP·Hed) were obtained. The thermal stabilities as latent initiators were tested: GPEs reacted with α‐ZrP·Pr, α‐ZrP·Bu, and α‐ZrP·Oct at 40 °C for 360 h achieved conversions of 83, 55, and 59%, respectively. In contrast, the reaction in the presence of α‐ZrP·Hed did not proceed at 40 °C. The order of the thermal stability of GPE in the presence of α‐ZrP·1‐aminoalkane intercalation compounds was: α‐ZrP·Hed > α‐ZrP·Bu ≈ α‐ZrP·Oct > α‐ZrP·Pr. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1854–1861     

Synthesis of highly reactive organosulfur compounds

Application of novel bowl‐type and dendrimer‐type steric protection groups to the first synthesis of stable aromatic S‐nitrosothiols is described. These compounds showed remarkable thermal stability whereas they easily reacted with appropriate reagents. X‐ray crystallographic analysis established their structures, where the C S N O linkage adopts only the syn conformation. Synthesis of a stable sulfenic acid by taking advantage of the bowl‐type substituent is also delineated. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:414–418, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10068     

N‐Azolylmethyl ketones as building blocks in heterocyclic synthesis: Synthesis of new polyfunctionally substituted azolylarylazophenols,azolylpyridones and azolylthiophenes

The title compounds 1a‐b and 2 reacted with 2‐arylhydrazonopropanals 3a‐c to yield polyfunctionally substituted azolylarylazophenols 5 and 8. The reaction of 1b and 2 with phenylisothiocyanate in the presence of α‐haloketones afforded the azolylthiophenes 12a,b and 13a,b. The reaction of 20 with α‐haloketone afforded 5‐benzotriazol‐1‐yl‐6‐methyl‐2‐(2‐oxopropylsulfanyl)nicotinonitrile 21 that was utilized as building blocks for the synthesis of condensed pyridines. Compound 21 was condensed with dimethylformamide dimethylacetal to yield thieno[2,3‐b]pyridin‐3‐yl‐N, N‐dimethylformamidine derivative 22. This was further cyclized with sodium hydride to 1H‐fhieno[2,3‐b; 4,5‐b']dipyridin‐4‐one derivative 23.     

Synthesis and Spectral Characterization of Some Novel Phosphonyl‐ and Phosphoryl Pyrazole Compounds

1,3‐Diphenyl‐1H‐pyrazole‐4‐carbaldehyde ( 1 ) reacted with aniline, 2‐substituted anilines, and P,P‐dimethylphosphinic hydrazide in the presence of diethyl phosphite to give acyclic α‐aminophosphonate 2 , cyclic α‐aminophosphonates 4–6 , and α‐hydrazinophosphonate 7 , respectively. Also, treatment of aldehyde 1 with cyanoaceto‐hydrazide, acetophenone, and malononitrile afforded the condensation products 8 , 16 , and 21 , respectively, which in turn, reacted with diethyl phosphite and P,P‐dimethylphosphinic hydrazide. The reaction of diethyl phosphite with the hydrazone 8 and chalcone 16 yielded the novel phosphorus heterocycles 13 and 18 , respectively, while its reaction with the dicyanoarylidene 21 produced the dicyanopyrazolyl phosphonate 22 . On the other hand, treatment of the hydrazone 8 with P,P‐dimethylphosphinic hydrazide gave the unexpected P,P‐dimethylphosphinic hydrazone 15 , which reacted with diethyl phosphite forming α‐hydrazinophosphonate 7 . Furthermore, the interesting N‐phosphoryl pyrazoles 20 and 24 were resulted in good yield via cycloaddition of P,P‐dimethylphosphinic hydrazide to the chalcone 16 and dicyanoarylidene 21 , respectively. Structures of all newly synthesized compounds were confirmed by considering the data of IR spectroscopy, MS, and ¹H‐, ¹³C‐, and ³¹P‐NMR spectroscopy, as well as that of elemental analyses.