Spiegelsymmetrische Hexahydro-1,2,4,5-tetrazine aus Pyrazolidon-(3)-N,N-betainen – ein Beitrag zur „thermischen Dimerisierung”︁ von 1,3-Dipolen

Mirror-symmetric Hexahydro-1,2,4,5-tetrazines from Pyrazolidine-3-one-N,N-betaines—a Contribution to the „Thermal Dimerization”︁ of 1,3-Dipoles Chemical reactions, i.r., ¹H-n.m.r., and ¹³C-n.m.r. data show that the “thermal dimers” of pyrazolidine-3-one azomethinimines 2 , which till now accidentally formed during the synthesis of 2 from pyrazolidine-3-ones 5 and aldehydes 6 , are 5,11-diaryl-perhydro-dipyrazolo[1,2-a; 1′,2′-d][1,2,4,5]-tetrazine-1,9-diones 3 , i.e. mirror-symmetric hexahydro-1,2,4,5-tetrazines with (C-5) and (C-11) placed on the mirror plane. From DREIDING models and from the nonequivalence, concerning ¹³C-n.m.r., of the pairs of carbon atoms in the o- resp. m-positions of the aryl substituent I at (C-5) of the “dimers” 3 is derived that the rotation of I is sterically hindered (ΔG = 16,3 kcal/mole for 3b ), and that the preferred arrangement of I is perpendicular to the plane of the hexahydrotetrazine ring. The “thermal dimerization” of the 1,3-dipoles 2 is a complex series of two addition and elimination steps proceeding in the presence of catalytical amounts of pyrazolidine-3-one 5 and of H^⊕. The mechanism is rationalized, consequences are suggested concerning known “dimerizations” of 1,3-dipoles.     

Direct Synthesis of Pyrazoles via reaction of C-ethoxycarbonyl-N-arylnitrilimines with benzalmalononitriles and some α-cyanocinnamic acid derivatives

Reaction of C-ethoxycarbonyl-N-arylnitrilimines ( 2a–d ) with α, β-disubstituted acrylonitriles ( 3a–f ) in refluxing benzene affords the corresponding substituted pyrazoles 5a–f and 6a–c respectively in good yield. However, reaction of 2a–e with 3g gives the 2-pyrazoline derivatives 7a–d . The assigned structures for the products 5–7 were confirmed by their spectra (i.r., ¹H-n.m.r.) and elemental analyses. Also the structures of the pyrazoles 5 were substantiated by comparison with their regioisomeres 8 .     

Reactions of 2-arylhydrazones of 1,2,3-triketones with 1,2-diaminoethane. I. Synthesis and spectral characterization of 6-arylazo-2,3-dihydro-1H-1,4-diazepines and 3,10-diarylazo-4,9-dimethyl-5,8-diaza-3,9-dodecadiene-2,11-diones

Reactions of 3-arylhydrazones of 2,3,4-pentanetrione ( 1a–1e ) and 2-arylhydrazones of 1,3-diphenyl-1,2,3-propanetrione ( 1f–1l ) with 1,2-diaminoethane have been studied. It was found, that 3-arylhydrazones of 2,3,4-pentanetrione react with 1,2-diaminoethane with formation of 6-arylazo-2,3-dihydro-1,4-diazepines ( 2a–2e ) or the diarylazo derivatives of 4,9-dimethyl-5,8-diaza-3,9-dodecadiene-2,11-dione ( 3a–3e ). Analogous reactions of 2-arylhydrazones of 1,3-diphenyl-1,2,3-propanetrione yielded exclusively the derivatives of dihydrodiazepine. The structure of obtained products has been elucidated on the basis of i.r., m.s. and ¹H-n.m.r. spectra.     

Sensibilisierte Photooxidation von Butadien-(1,3)-sultamen-(1,4)

Sensitized Photooxidation of Butadiene-(1,3)-sultames-(1,4) The sensitized photooxidation of the butadiene-sultames 1a–d gives 2-aryl-3,5-dimethyl-5-hydroxy-1,1,6-trioxo-5,6-dihydro-2H-1,2-thiazines 2a–d in yields of 60%. The compounds 2a–d are instable against bases and acids. With triethylamine the N-aryl-5-hydroxypyrrolin-2-ones 5a–d are formed by SO₂-extrusion. With alkali 2b reacts to 5b and cis-β-acetyl-methacrylic acid 4 . ¹H- and ¹³C-n.m.r. spectroscopic data of 2 and 5 are given.     

Synthese und Reaktionen von 1,3-Azaphosphorinan-2-thionen

Synthesis and Reactions of 1,3-Azaphosphorinane-2-thiones Aminopropylphosphines, R P(H) (CH₂)₃ NH₂, react with carbon disulfide to give 1,3-azaphosphorinane-2-thiones. In presence of strong bases the title compounds are converted by alkyl halides into 2-alkylthio-3, 4, 5, 6-tetrahydro-1, 3-azaphosphorines whereas in absence of bases quaternization at the phosphorus atom occurs to give 2-thiono -1,3-azaphosphorinanium salts. The structures of the compounds prepared are elucidated by IR. ¹H-n.m.r. and mass spectra.     

Flüssigphasenoxidation von 1,3-Dioxolanen

Liquid Phase Oxidation of 1,3-Dioxolanes The oxidation rate and the kind of oxidation products in the oxidation reactions of the 1,3-dioxolanes ( 1a to 1f ) with molecular oxygen in liquid phase were investigated. The 2-methyl-substituted 1,3-dioxolane ( 1b ) has a lower, the 4-methyl-substituted 1,3-dioxolane ( 1d ) has a higher oxidation rate than the non-substituted 1,3-dioxolane ( 1a ). The 2,2-disubstituted 1,3-dioxolanes show no oxidation but a hydrolytic reaction. The main-products of the liquid-phase oxidation of the 1,3-dioxolanes 1a , 1b , 1d and 1e are the glycol-carbonic acid-monoesters 8 and the 2-oxo-1,3-dioxolanes 6 . Their formation is proved by gaschromatography, GC/MS-coupling, DC and ¹³C-n.m.r.-spectroscopy.     

Tetrathiafulvalene. XIX. Synthese und Eigenschaften elektronenleitender Poly-Dithiolenkomplexe mit Ethylentetrathiolat und Tetrathiafulvalentetrathiolat als Brückenliganden

Tetrathiafulvalenes. XIX. Synthesis and Properties of Electron Conducting Poly-Dithiolene Complexes with Ethylene Tetrathiolat and Tetrathiafulvalene Tetrathiolat as Bridge Ligands [1,3]-Dithiolo[4,5-d]-1,3-dithiol-2,5-dione 7 and 5-(5-oxo[1,3]-dithiolo[4,5–d]1,3-dithiole-2-ylidene)[1,3]-dithiolo[4,5–d]1,3–dithiol-2-one 8 were synthesised from 1,3-dithiole-2-thione-4,5-dithiolat. The ligands react with salts of iron, cobalt, nickel, palladium, platinum and copper to give the polymer complexes 22a–g and 23a–e , respectively. Irradiation of 7 in the presence of iron penta-, dicobalt octa- or nickel tetracarbonyl gives the corresponding dithiolene complexes 21a–c . The amorphous insoluble polymer complexes from types 21, 22 , and 23 have been characterised by i.r.-spectroscopy, susceptibility and conductivity measurements. The nickel complexes have the highest electrical conductivity (σ_RT ∼ 10⁻¹Ω⁻¹cm⁻¹, pellets) with a very low activation energy (0,045 eV, 100–300 K) A high electron delocalization in the direction of the polymer chain and an easy charge transfer from chain to chain is supposed.     

Silica gel-promoted new one-pot procedure for the synthesis of 1,3-oxathiolan-5-one

A highly selective two-component silica gel-promoted synthesis of 1,3-oxathiolan-5-one derivatives in N,N-Dimethylformamide (DMF) is presented. The reaction was carried out using aromatic aldehyde and mercaptoacetic acid in the presence of silica gel in DMF with heating. The reactions were worked up by separating the silica gel and recovering the solid product after adding water in excellent yields without any chromatographic purification. Structures of the compounds were satisfactorily confirmed by ¹H NMR and LCMS spectral analysis.     

Pyryliumverbindungen. 45 [1]. 4-Aroyl-fluorene aus 2,4,6-Triaryl-pyryliumsalzen und Indan-1-on via 2-(5-Oxo-pent-2-en-1-yliden)-indan-1-one

Pyrylium Compounds. 45. 4-Aroyl-fluorenes from 2,4,6-Triaryl-pyrylium Salts and Indan-1-one via 2-(5-Oxo-pent-2-en-1-yliden)-indan-1-ones 2,4,6-Triarylpyrylium salts 1 react with indan-1-one in the presence of an appropriate buffer system (e.g. piperidine acetate, triethylamine/acetic acid, triethylamine or sodium acetate) to yield the 2-(1,3,5-triaryl-5-oxo-pent-2-en-1-yliden)-indan-1-ones 2 . For the reaction medium aliphatic alcohols (methanol, ethanol), dipolar aprotic solvents (acetonitrile) or chlorinated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride) can be used. On treating 2 with sodium methanolate in methanol, a cyclization reaction occurs giving rise to the 4-aroyl-1,3-diaryl-fluorenes 3 . As by-products 1,3-diaryl-fluorenes 8 (e.g. 1,3-diphenyl-fluorene) are formed. - I.r., n.m.r. and u.v. spectroscopic data of the novel compounds 2 and 3 are reported.     

Photochemie und Photophysik von 3-(2-Isoxazolinyl)-phenylketonen

Photochemistry and Photophysics of 3-(2-Isoxazolinyl)-phenylketones 3-Benzoyl-Δ²-1,2-oxazolines ( 1–6 ) are formed by 1,3-dipolar cycloaddition between benzoylnitril-N-oxide ( 8 ) and dihydrofurane 9 or 1,3-dioxep-5-enes ( 10a–c ). The preparative yields are small due to the competitive dimerization of the dipole 8 . Two stereoisomers are obtained by using 2-substituted 1,3-dioxep-5-enes as dipolarophiles. The different steric position of the substituents in 3–6 gives rise to different spectral data. The synthesized ketones possess triplet states with a high degree of charge transfer character. Therefore, the ability to H-abstraction reaction from alcohols is small. For ketone 2 and methanol as H-donor a rate constant of k = 4,1 · 10² M⁻¹s⁻¹ is determined. Also by electron transfer reactions with triethylamine and some onium compounds the reactivity of the T₁ of the ketones 1–6 is less compared to those of nπ* excited ketones. The photolysis of the ketones takes place very unselectively and leads to a product mixture. The quantum yields for the decay of the ketones are 10⁻² to 10⁻³.     

Solid Polymer Electrolytes Based on Poly(1,3-diacetyl-4-imidazolin-2-one)

Summary Solid polymer electrolytes composed of a homopolymer (poly(AcIM)) of 1,3-diacetyl-1,4-imidazolin-2-one (AcIM) and lithium bis(trifluoromethanesulfonimide) (LiTFSI) or of copolymers (poly(AcIM/VC)) of AcIM with vinylene carbonate (VC) and LiTFSI were prepared and their ionic conductivities and thermal properties were investigated. For the polymer electrolyte of the poly(AcIM) with LiTFSI, the highest ionic conductivity was found at the [Li]/[O] ratio of 1/3 with the values of 8.5×10^-5 S/cm at 80 °C and 1.7×10^-6 S/cm at 30 °C, respectively. In the polymer electrolyte of poly(AcIM/VC) with LiTFSI at the [Li]/[O] ratio of 1/3, the ionic conductivity increased with increasing VC unit content in the copolymers, and the highest ionic conductivity was found at the AcIM/VC ratio of 39/61 (mol%) with the values of 7.0×10^-4 S/cm at 80 °C and 6.7×10^-5 S/cm at 30 °C, respectively. This copolymer electrolyte showed a linear relationship between the ionic conductivity and the reciprocal of the temperature, indicative of the system decoupled from the segmental motion of the polymer.     

Synthesis, degradation and in vitro controlled drug release of novel copolymers of 5-methyl-5-methoxycarbonyl-1,3-dioxan-2-one and caprolactone

Novel biodegradable copolymers of 5-methyl-5-methoxycarbonyl-1,3-dioxan-2-one (MMTC) and caprolactone (CL) were synthesized under different conditions by ring-opening polymerization. The structure of the resultant copolymers was characterized by IR, ¹H NMR and ¹³C NMR methods. Their molecular weight was measured by gel permeation chromatography (GPC). Incorporating the MMTC units into PCL main chain results in the great enhancement of hydrolytic degradation rate and the effective retardance of release rate of Tegafur in comparison with the PCL homopolymer. The enzymatic degradation rate increases with increasing the molar content of PCL, and the copolymers degrade faster in the presence of pseudomonas (PS) lipase than that in the absence of PS lipase. Some mechanical properties of the copolymers were tested and showed that they can be adjusted by varying the composition of the copolymers.     

Synthesis of some new spiroheterocyclic pyrylium salts related to 1-oxa-4-thiaspiro[4.4] nonan-2-one and/or [4.5]decan-2-one as antimicrobial agents

1-Oxa-4-thiaspiro[4.4]nonan-2-one ( 1a ) and/or 1-oxa-4-thiaspiro[4.5] decan-2-one ( 1b ) were reacted with aniline and/or p-chloroaniline to afford the corresponding spirothiazolidinones ( 2a–d ). Reaction of 2a–d with chalcones gave 2-(α – paracylbenzyl)-4-aryl-1-thia-4-azaspiro[4.4]nonan-3-one and 2-(α-aracylbenzyl)-4-aryl-1-thia-4-azaspiro[4.5]decan-3-one ( 3a–p ) respectively. Compounds 3a–p were reacted with acetic anhydride and perchloric acid to yield the spiropyrano[2,3-d]thiazol[4]ium perchlorate derivatives 4a–p . The structures of the synthesized compounds were elucidated by elemental and spectroscopic ( IR and ¹H-NMR) analysis. All the prepared compounds were tested for their antimicrobial activities in comparison with tetracyclic as a reference compound.     

Strukturuntersuchungen an einem Produkt der intramolekularen Diels-Alder-Reaktion Konfigurations- und Konformationsanalyse von 5-Methyl-2-phenyl-1H-2,3,3a,4,5,7a-hexahydroisoindol-1-on

Structure Elucidation of a Product of Intramolecular Diels-Alder-Reaction: Configurational and Conformational Analysis of 5-Methyl-2-phenyl-1H,2,3,3a,4,5,7a-hexahydroisoindol-1-one N-Allyl-N-phenylsorbamide 1 cyclizes at 160°C to give 5-methyl-2-phenyl-1H,2,3,3a,4,5,7a-hexahydroisoindol-1-one 2 . As a result of this intramolecular [4 + 2] cycloaddition four stereoisomeres 2a–2d can exist. The ¹H and ¹³C n.m.r. data are given. The ¹H n.m.r. studies demonstrate that the product of Diels-Alder cyclisation is the result of cis-fusion of the two rings. The nuclear Overhauser effect data provide further evidence for 2a in which the carbonyl group and methyl one are trans-arranged. The n.m.r. results are confirmed by X-ray studies.     

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.     

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.     

4,5-二甲基-1,3-二氧杂环戊烯-2-酮的合成

该文以有机碱作为缚酸剂,研究了4-氯-4,5-二甲基-1,3-二氧杂环戊烷-2-酮(CDMDO)脱氯化氢制备4,5-二甲基-1,3-二氧杂环戊烯-2-酮(DMDO)的工艺。优化的工艺条件为:N,N-二甲基苯胺作为缚酸剂,甲苯为溶剂,反应温度110℃,CDMDO转化率70%。     

Organophosphorus chemistry. 13 [1]. The Behaviour of 3-Aryliminoxindoles toward Alkyl Phosphites

3-Aryliminoxindoles ( 6a–c ) react with trialkyl phosphites (TAP, 2a–c ) only in presence of a protonating agent (H₂O or CH₃COOH) to give the respective dialkyl 3-(arylamino-2-oxo-1H-indol-3-yl)-phosphonates ( 9a–i ). Compounds 9 are equally obtained by reacting 6a–c with the appropriate dialkyl phosphite (DAP, 4a–c ) in absence of solvent. The role displayed by the arylimine-moiety on the reaction courses is discussed. A mechanism that accounts for formation of 9 from the reaction of anils 6 with TAP, is presented. Structural assignment are based upon analytical, chemical and spectroscopic (i.r., ¹H-n.m.r., ³¹P-n.m.r. and m.s.) results.     

Synthesis and properties of novel biodegradable triblock copolymers of poly(5-methyl-5-methoxycarbonyl-1,3-dioxan-2-one) and poly(ethylene glycol)

Novel biodegradable triblock copolymers of poly(5-methyl-5-methoxycarbonyl-1,3-dioxan-2-one) (PMMTC) with poly(ethylene glycol) (PEG), PMMTC-b-PEG-b-PMMTC, were synthesized by the ring-opening polymerization of MMTC in bulk, using the dihydroxyl PEG as initiator and Sn(Oct)₂ as catalyst. The triblock copolymers with different compositions were characterized by IR and ¹H NMR, their molecular weight was measured by gel permeation chromatography (GPC). The results showed that the molecular weight of triblock copolymers increased either with the increase of the molar ratio of MMTC in feed while the PEG chain length kept constant, or by lengthening the backbone chain of PEG block with the same ratio of MMTC in feed. The hydrophilicity of copolymers was greatly improved by incorporation of PEG block into polycarbonate. The in vitro hydrolytic/enzymatic degradation and controlled drug release properties of the triblock copolymers were also investigated.     

Heterocyclic syntheses with malonyl chloride. 15. 7-Chloro-3,4-dihydro-4,5-dioxo-3-aryl(or-alkyl)-2-thio-2H,5H-pyrano[3,4-2-e]-1,3-oxazine from aryl or alkyl isothio-cyanates and their degradation with morpholine and ethanol

Substituted aromatic isothiocyanates with malonyl chloride yield 7-chloro-3-substituted-3,4-dihydro-4,5-dioxo-2-thio-2H,5H-pyrano [3,4-e]-1,3-oxazine ( 1 ). Alkyl isothiocyanates with malonyl chloride yield a mixture of 7-chloro-3-alkyl-2-thio pyranooxazine ( 2 ) and the 2-oxo-analogue ( 3 ). The pyrano oxazine 1 react stepwise with morpholine undergoing replacement of the 7-chloro substituent yielding the 7-morpholino analogue ( 4 ), then the pyrone ring was opened producing 5-morpholino carbonyl-4-oxo-3-substituted phenyl-2-thio-1,3-oxazine-6-ylacetomorpholid ( 5 ). Finally the oxazine ring was opened yielding 2-substituted phenyl carbomyl-3-morpholino-N,N-glutaconoyldimorpholine ( 6 ). Ethanol react with compound 1 at any molar ration causing the opening of the pyrone ring and retain the oxazine ring. Mass spectra. ¹H-n.m.r., u.v. and i.r. spectroscopic data provided information about the fine structures of the products.