A novel synthesis of 1,3 Thiazetidine-2-one and 1,3-Oxazine-2-one Derivatives

In the reactions of acetylthioacetanilides ( 1a–c ) and diacetylthioacetanilides ( 3a–f ) with phosgene 1,3-thiazetidine-2-one ( 2a–c ) and 1,3-oxazine-2-one ( 5a–f ) were obtained respectively. The structures of new compounds were elucidated by elemental analyses, i.r., ¹H-n.m.r., m.s., for 1d–f by ¹⁹F-n.m.r. and for 2a and 5a by ¹³C-n.m.r. spectral data.     

Ableitung und Diskussion rationeller 1H-NMR-Struktur-parameter für 1,3-bzw. 1,5-disubstituierte Pyrazolderivate

Discussion and Rationalization of ¹H-n.m.r. Parameters for the Structural Assignment of 1,3- or 1,5- Disubstituted Pyrazoles For 44 1,3-disubstituted ( 1 ) or 1,5-disubstituted pyrazoles ( 2 ) with growing polarity μ of solvent the ¹H-chemical shift δ (HC-5) (for 1 ) increases considerably more than δ (HC-3) (for 2 ), and, depending on the 5-substituent, δ (HC-3) often even decreases. This is interpreted in terms of nucleophilic interaction between polar solvent and “pyridine-like” pyrazole-(N-2), in enhancement of the contributions of polar canonical structures, in substituent effects, and in influences of the pyrazole dipole moments μ_r. Resultant dipole moments μ_r of disubstituted pyrazoles with the 3-resp. 5-substituents Me, Cl, NH₂, and OMe, and their projections μ′_r on the H-(C-5)-resp. H-(C-3)- bond axes are calculated. The chloro-pyrazoles 1h, 1i, 2h and 2i , 3-methoxy-, and 5-methoxy-1-benzyl-pyrazole are synthesized unambiguously. is recommended as significant parameter for the structural assignment of 1,3-disubstituted pyrazoles 1 and 1,5-disubstituted pyrazoles 2 .     

Synthesis of biologically active 4-benzyl-1(2H)-phthalazinones and 2-aryl-3(2H)-1-benzal-isoindolinones

4-Benzyl-2-1(2H) phthalazonyl derivatives of type 2, 3, 5a, b were synthesized by Mannich reaction of 4-benzylphthalazinone 1 which by the reaction with diazomethane yielded O-methylated derivative 4 . Various 1-benzal-2-substituted aryl-3(2H) isoindolinones 7a–f, 8a–e were also prepared. Its i.r., ¹H-n.m.r. and mass spectra were discussed. Some of them exhibit pronounced antimicrobial activities. A number of phthalazinones have found application in clinical medicine [1–3] due to the their pronounced antipyretic, analgesic and tuberculostatic activity and the importance of some benzylidenephthalimidines as stabilisers for halogen containing high polymers [4] and the local anesthetic activity superior to that of procaine [5], tempted us to procure some new phthalazinones and isoindolinones with biological interest.     

Synthesis and some reactions of 1-(4.6-dimethoxybenzo-furanyl)- and 1-(4.6.7-trimethoxybenzofuranyl)butane-1.2.3-trione-2-arylhydrazones

Both 4.6-dimethoxy-( 1c ) and 4.6.7-trimethoxy-5-acetoacetylbenzofuran 1d are obtained from visnaginone ( 1a ) and khellinone methyl ethers 1b , respectively, by a CLAISEN condensation. The β-diketones 1c and 1d couple with aromatic diazonium compounds to form the hydrazones 2a – i . 1-(4.6-Dimethoxybenzofuranyl)- and 1-(4.6.7-trimethoxybenzofuranyl)butane-1.2.3-trione-2-arylhydrazones 2 a–i react with hydrazine hydrate in acetic acid to yield the corresponding pyrazole derivatives 3a–i or 4a–i . The monohydrazones 5a–b are isolated when 2e or 2i are treated with hydrazine hydrate in ethanol. The hydrazones are converted to the respective pyrazoles by the action of glacial acetic acid. Hydroxylamine hydrochloride reacts with 1.2.3-trione-2-arylhydrazones 2a, c, e, f and i to yield the corresponding isoxazole derivatives 6a–e or 7a–e . The 2-arylhydrazones 2a, c, d, e, h and i form the corresponding pyrazole derivatives 8a–f when treated with semicarbazide hydrochloride.     

3,3-Bis[alkylthio]-phenylacrylaldehyde als Bausteine für Thiophene und Pyrazole

3,3-Bis[alkylthio]-2-phenylacrylaldehydes as Building Sets for Thiophenes and Pyrazoles Alkylation of the dithiolate 2 either with methyliodide and α-CH-acid halogenated compounds R² CH₂ X or only with the latter reagent yields ketene S,S-acetals 3 . Base catalyzed cyclization of 3 leads to the thiophenes 4 Reaction of 3,3-bis[methylthio]-2-phenylacrylaldehyde 3f with hydrazine affords a mixture of aldehydrazone 5 and aldazine 6 . The pyrazole 7a is obtained by refluxing 5 in 1-butanol. Mass spectra of the pyrazoles 7b, c and reaction of 3f with aniline prove the attack of a nucleophile on the formyl group in the first step.     

Cyclofunktionalisierung von 2-Allyl-phenolen mit Schwefelchloriden. 2-Arylthiomethyl-2,3-dihydrobenzofurane aus 2-Allyl- und 2-Methallyl-phenolen und Arylsulfenylchloriden

Cyclofunctionalization of 2-Allyl-phenols with Sulfur Chlorides: Synthesis of 2-Arylthiomethyl-2,3-dihydrobenzofurans by Reaction of 2-Allyl- and 2-Methallyl-phenols, Respectively, and Arylsulfenyl Chlorides Reactions of acetylamino substituted 2-allyl-phenols ( 1 and 2 ), and 2-methallyl-phenol ( 6 ), respectively, with different arylsulfenyl chlorides ( 3a—d ) yield the products of a cyclofunctionalization 5- or 7-acetylamino-2-arylthiomethyl-2,3-dihydrobenzofurans ( 4a–d ) or ( 5a–d ) and 7-acetylamino-2-arylthiomethyl-2-methyl-2,3-dihydrobenzofurans ( 7a–d ). The compounds 7 are the first examples of cyclofunctionalization of 2-methallylphenols by means of sulfur chlorides. The identification of the products was carried out by mass spectrometry, ¹H-n.m.r. spectroscopy and elemental analysis.     

4-(1-Methyl-2-sulfamoylvinyl)pyrazoles by Ring Transformation of 1,1-dioxo-2H-1,2-thiazine-4-carbaldehydes with hydrazines

As masked 1,3-dicarbonyl compounds, 1,1-dioxo-2H-1,2-thiazine-4-carbaldehydes ( 2a–e, 7 ) undergo ring transformations with nucleophilic hydrazines to produce 4-[1-methyl-2-(arylsulfamoyl)vinyl]pyrazoles ( 9a–i ). For 9h , an X-ray structural analysis is reported. With less nucleophilic semicarbazide and p-nitrophenylhydrazine the hydrazones ( 11a, b ) were isolated. The carbaldehydes 2a–e , 7 and 8a, b were synthesized by formylation of the 1,1-dioxo-2H-1,2-thiazines 1a–e, 5 and 6a, b with dichloromethyl methyl ether/TiCl₄. In the case of 1a–e mixtures of 4- and 6-carbaldehydes ( 2a–e/3a–e ) were obtained, which, however, could be used for the synthesis of pyrazoles.     

Allgemeine Synthesen und rationelle Strukturparameter isomerer Derivate von [3,4]-kondensierten Pyrazolen

General Syntheses and Rational Parameters for Structural Assignment of Isomeric Derivatives of [3,4]-fused Pyrazoles 4 isomeric 1- or 2-methyl-, and 1- or 2-benzyl-pyrazolo[3,4-b]pyridones, i.e. the 4-oxo-types 17a, b or 11a, b and the 6-oxo-types 16a, b or 10a, b , are synthesized unambiguously. Cyclisation of 1-substituted 3- or 5-(1-methyl-2-ethoxycarbonyl-vinylamino)-pyrazoles 9a, b or. 15a, b , which were synthesized from 1-substituted 3- or 5-amino-pyrazoles and ethyl acetoacetate yields 11a, b or 17a, b in downtherm, but 10a, b or 16a, b in presence of acidic catalysts. The acidic cyclisation is preceded by a new rearrangement of 9 or 15 into 1- substituted 3- 27 or 5-amino-4-(1-methyl-2-ethoxycarbonyl-vinyl)-pyrazoles 30 ; mechanism and concurring reactions are explained. Because of their higher electron densities at C-4 it is easier to cyclise derivatives of 5-amino-pyrazoles compared to 3-amino-pyrazoles. All isomeric 1- or 2-substituted 4(6)-chloro-6(4)-methyl-pyrazolo-[3,4-b]pyridines are formed with POCl₃ from the corresponding oxo-compounds. The position of a substituent at N-1 or N-2 of [3,4]-fused pyrazoles can be assigned using the significant ¹H-n.m.r.-parameter Δ = δ — − δ_HMPT (conc. HC—3). If solvent influences are considered, δ(C  O) is a useful ¹³C-n.m.r.-parameter to distinguish the 4-oxo-types ( 11a, b; 17a, b ) from the 6-oxo-types ( 10a, b; 16a, b ) of pyrazolo[3,4-b]pyridones. Further own and lit. dates conc. structural assignment (n.m.r., i.r., u.v.) are discussed critically.     

Furanderivate. VII. 2-[Furyl-(2)- und 5-Nitro-furyl-(2)]vinylphosphonsäure-O,O-diethylester

Furanderivatives. VII. O,O-Diethyl-2-[furyl-(2)- and 5-nitro-furyl-(2)] vinylphosphonates Syntheses and spectroscopic properties (i.r., u.v., ¹H-, and ¹³C-n.m.r.) of the title compounds existing as E-isomers with the general structure 1–8 (R⁵  H, NO₂; R  CN, COOEt, H, NMe₂) are represented. According to spectroscopic data the compound 8 (R⁵  NO₂; R  NMe₂) differs in its electronic structure.     

Radikalreaktionen an N-Heterocyclen. XI [1] Reaktionen von 3-Methyl-pyrazolin-5-onen mit Phenoxyl-Radikalen

Free Radical Reactions of N-Heterocyclic Compounds. XI. Reaction of 3-Methyl-pyrazolin-5-ones with Phenoxy Radicals Pyrazolin-5-ones ( 3a–i ) were oxidized with 2,4,6-trisubstituted phenoxy radicals ( 2a–d ) to the corresponding radicals ( 4a–i ), which dimerised or combined with phenoxy radical ( 2a ) depending on the R¹- and R⁴-substituents in ( 3 ). In the case of 3-methyl-1-phenyl-pyrazolin-5-one ( 3f ) the primary radical combination products were not found, but the corresponding quinone methide ( 17 ) and the o-phenol derivative ( 18 ) were isolated. Products and yields have been investigated as a function of mol ratio substrate: oxidant and solvent. The radical combination products ( 7–10 ) could de-tertbutylated in the presence of aluminium chloride or in the presence of trifluoroarcetic acid, forming heterocyclic substituted phenols ( 21 ) and ( 22 ).     

Struktur und Isomerisierung der 1,3-dipolaren Cycloaddukte von Malein- und Fumarsäure-dimethylester an Pyrazolidon-(3)-azomethinimine

Structures and Isomerisation of the 1,3-Dipolar Cycloadducts of Dimethyl Maleate and Fumarate to 3-Pyrazolidone-azomethinimines The 1,3-dipolar cycloaddition of dimethyl maleate 1b and fumarate 5b to the 3-pyrazolidone-azomethinimine 2 is a stereospecific cisoid reaction yielding the perhydropyrazolo[1,2-a] pyrazoles 3b/4b in the molar ratio of 2:1, and 6 b/7b in the molar ratio 1:1. Starting with each of the 4 stereoisomers, epimerization, catalysed by alcoholate, results in all 4 of them 3b, 4b, 6b and 7b with 7b as sterically favoured main product. During the addition reaction no epimerization is occurring. ¹H- and ¹³C-n.m.r. data are discussed.     

Processable high Tg high strength fluorinated new poly(arylene ether)s containing imido aryl group

A series of poly(arylene ether)s ( 7a–7f ) were successfully synthesized by aromatic nucleophilic substitution reactions of imidoaryl biphenol (5), 4,9‐bis‐(4‐hydroxy‐phenyl)‐2‐phenyl‐benzo[f]isoindole‐1,3‐dione with six different trifluoromethyl substituted bisfluoro monomers ( 6a–6f ). The weight‐average molar masses of the polymers were up to 280 kD as measured by GPC. These poly(arylene ether)s exhibited glass transition temperatures up to 361°C in DSC. These polymers showed very high thermal stability up to 558°C for 10% weight loss under synthetic air in TGA. Except 7d–7f, remaining polymers 7a–7c were soluble in a wide range of organic solvents. Transparent thin films of these polymers cast from DCM or NMP exhibited tensile strengths up to 75 MPa and elongation at break up to 41% depending on their exact repeating unit structures. These poly(arylene ether)s showed cut‐off wavelength in between 400 and 450 nm except 7d and water absorption were in the range of 0.4 to 0.6%. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Steroide. XLVI. Darstellung von 15.16.17-trisubstituierten Steroiden durch Ringöffnung von 17β-substituierten 15β.16β-Epoxy-östra-1.3.5(10)-trien-3-methyläthern

Steroids. XLVI. Preparation of 15,16,17-Trisubstituted Steroids by Ring Cleavage of 17β-Substituted 15β,16β-Epoxy-estra-1,3,5(10)-triene 3-Methylethers The ring cleavage of 15β.16β-epoxy-3-methoxy-estra-1-3,5(10)-triene-17β-ol 1a with strong nucleophiles occurs mainly at C-16, yielding 16α-substituted 15β,17β-diols 2a–f . Besides this, 1a is cleaved to a small extent at C-15, yielding the 15α-substituted 16β,17β-diols 3a—f and the Δ¹⁴-16,17β-diol 5a . The structures have been elucidated by means of i.r., H-n.m.r. and mass spectroscopy.     

Reactions with 2-thiazolin-5-ones. III. The behaviour of 4-Arylazo-2-alkoxy-2-thiazolin-5-ones toward amines and Grignard reagents

Treatment of 4-arylazo-2-alkoxy-2-thiazolin-5-ones 4a – f with glycine or phenylhydrazine effects their conversion into 1-aryl-5-alkoxy-1 H-1,2,4-triazole-3-carboxylic acid derivatives 5a – j , with the loss of hydrogen sulfide. On the other hand, the reaction of the 2-ethoxy ( 4a – c ) and the 2-isopropyloxy ( 4g – i ) derivatives with strong basic amines involves the loss of an alkyl mercaptan to yield the N-substituted amines 7d – j of 1-aryl-Δ²-1,2,4-triazolin-5-one-3-carboxylic acids. The 2-benzyloxy derivatives 4d – f react with the same reagents to give the N-substituted amides 2a – g of 1-aryl-Δ²-1,2,4-triazolin-5-thione-3-carboxylic acids, with the loss of benzyl alcohol. Hetero-ring opening of 4 , followed by recyclisation, occurs upon treatment with ethyl or phenyl magnesium halides to yield the triazolinethione derivatives 13 a – c .     

Characteristics,Thermodynamics, and Preparation of Nanocaged 12CaO·7Al2O3 and Its Derivatives

Crystal s tructures, characteristics, and preparations of 12CaO·7Al₂O₃ family and CaO–Al₂O₃ (C–A) system have been reviewed in detail with relevant thermodynamic parameters being assessed or recalculated. 12CaO·7Al₂O₃ (shortened as C12A7) can form several derivatives of type C12A7:M^n? or C12A7–M^n? through replacing so‐called “free oxygen ion” by many anions including OH^?, H^?, O^?, , F^?, Cl^?, and e^? in their cages, or being adopted by rare earth metals or alkaline earth metal oxides at cation sites (Ca²⁺ or Al³⁺). These doped C12A7 derivatives show unique material properties of transparent conduction, catalysis, and antibacterial with potential applications in fast ion conductors, optoelectronics, oxidants, and catalysts etc.     

Luminescent properties of MgAl2O4 ceramics doped with rare earth ions fabricated by spark plasma sintering technique

MgAl₂O₄ ceramics doped with rare earth ions (Eu²⁺ and Ce³⁺ ions) were fabricated by spark plasma sintering technique. A complex characterization of the crystalline and defect structure of the ceramic by XRD was carried out. Absorption, excitation, photo- and cathodoluminescence spectra were studied. The photoluminescence spectrum shifts to the blue region with a maximum at λ_em =?475?nm for the MAS:0.1Ce ceramics. The nature of this luminescence can be caused by the radiative transitions in the cerium ion 5d–4f. The emission spectrum of MAS:0.1Eu has a “green” band emission in range of 400–700?nm centered around 500?nm, which can be ascribed to the allowed 4f⁶5d¹→4f⁷ (5d–4f) transition of Eu²⁺. In the millisecond time range, simultaneously with the emission of the complex host centers, the impurity luminescence bands of the chromium ion are recorded. It was shown that cathodoluminescence spectra in nanosecond time range can be decomposed into several emission bands at 2.72, 3.01, 3.37, 3.63–3.82?eV caused by F-type centers. It was demonstrated that the Eu²⁺ and Ce³⁺ ions lead to change the intensity ratio of the luminescence bands. The luminescence decay kinetics of synthesized spinel ceramics in nano- and millisecond time range were investigated in detail.     

The synthesis,characterization and structures of some 4-[((E)-1-{2-hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene)amino]benzoic acid

The structures of several azo-benzoic acids, 4-[((E)-1-{2-hydroxy-5-[(E)-2-(aryl)-1-diazenyl]phenyl}methylidene)amino]benzoic acid along with their precursors 2-hydroxy-5-[(E)-(aryldiazenyl)]benzaldehydes were confirmed using ¹H, ¹³C NMR, UV–VIS and IR spectroscopic techniques. UV–VIS absorption spectra were measured in pure organic solvents while complementary spectroscopic experiments using mixed solvent systems as well as in the presence of base were undertaken to characterize the different species present in solution. Both acid–base dissociation and azo–hydrazone tautomerism occurred in solution, with the extent of the individual equilibria being dependent on the solvent composition and/or pH of the medium. Molecular structures and geometries were optimized using the B3LYP density functional theory method employing the 6-31G(d) basis set.     

Amino-thieno[2,3–c]pyrazole und Amino-thieno[2,3–b]pyrrole

Amino-thieno[2,3–c]pyrazoles and Amino-thieno[2,3–b]pyrroles The synthesis of thieno[2,3–c]pyrazoles and thieno[2,3–b]pyrroles is described. From the dithioliumsalt ( 1 ) and potassium hydroxide the potassium-(2,2-dicyan-1-methylthio-ethen-1-yl)-thiolate ( 2 ) is formed. This reacts with hydrazine hydrate to form the 3-amino-5-thioxo-pyrazol-4-carbonitrile ( 3 ) S-Alkylation with α-chlorocarbonyl compounds yielding ( 6a–c ) leads via Thorpe-Ziegler-cyclization to 3,4-diamino-thieno[2,3–c]pyrazoles ( 9 ) if the position 1 is alkylated ( 8 ). Acetyl acetone yields 2-mercapto-pyrazolo[1,5–a]pyrimidine ( 5 ). After S-alkylation ( 10a–d ) are immediately cyclized to thieno [2′,3′:3,4]pyrazolo[1,5-a]pyrimidine ( 11a–d ). The ketone ( 6a ) can be cyclized to the pyrazolo [5,1–b]thiazole ( 12 ). 3 reacts with oxalyl chloride to form the 2,3-dioxo-6-thioxo-imidazo[1,2-b]pyrazole ( 13 ) of which S-phenacyl derivative ( 14 ) because the NH-proton cannot be cyclized. The 5-amino-3,4-dicyano-pyrrol-2-thiolate ( 16 ) shows the analogous behaviour. The S-alkylation is followed by cyclization, and 3,5-diamino-thieno[2,3–b]pyrroles ( 18a–b ) arise. Reaction of 5-amino-2-alkylthio-pyrrol-3,5-dicarbonitrile ( 17 ) with acetyl acetone provides pyrrolo[1,2-a]pyrimidine ( 20a–c ) which can be cyclized to form thieno[3′,2′:4,6]pyrimidines ( 21a–c ) very easily.     

Waterborne cationomer polyurethane coatings with improved hydrophobic properties

The AFM method was used to investigate the phase structure of the coatings, which have been obtained after application of polyurethane cationomers, synthesized in the reaction of 4,4′‐methylenebis(phenyl isocyanate) or isophorone diisocyanate with polyoxyethylene glycol (M = 600) and N‐methyl or N‐butyldiethanolamine with 2,2,3,3‐tetrafluoro‐1,4‐butanediol. Changes were discussed in the surface‐free energy (SFE) and its components, as calculated independently according to the method suggested by van Owens–Wendt, in relation to chemical structures of cationomers, as well as morphology of coating surfaces obtained from those cationomers. Fluorine incorporated into cationomers (about 2–5%) contributed to lower SFE values, down to about 30 mJ/m². An attempt was made to use ¹H‐NMR spectroscopy to provide more extensive grounds for the effect of polyurethane chemical structures (by parameters κ) on the SFE of coatings obtained from such polyurethanes, with the values of SFE (γ_S, γ) and determined by the Owens–Wendt method. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Influence of anionic form on thermal degradation of TMAHP–cellulose

Trimethylammoniumhydroxypropyl (TMAHP)–cellulose in 10 anionic forms (F^?, Cl^?, Br^?, I^?, HSO, NO, OH^?, HCO, H₂PO, CH₃COO^?) was prepared, and the influence of each anion on thermal degradation in inert atmosphere was studied. With the help of dynamic and isothermal thermogravimetry (TG) it was found that H₂PO ions had the greatest retarding effect on TMAHP–cellulose degradation. From the values of rate constants it can be seen that all ionic forms of TMAHP–cellulose have the starting rate of thermal degradation greater than unmodified cellulose. The calculated values of activation energy of thermal degradation for different ionic forms are decreasing in following sequence: H₂PO > F^? > NO > I^? > Br^? > HCO > Cl^? > HSO > OH^? > unmodified cellulose > CH₃COO^?. From the results of pyrolyse measurements in combination with gas chromatography and mass spectrometry (Py–GC–MS) it follows that the products of the elimination of quarternary ammonium salts are trimethylamine, 3-hydroxy-2-propanone, and, in the case of OH^? form, water. In all other ionic forms the third product is the corresponding acid.