Synthesis of perfluorobicyclic ethers [2]. The electrochemical fluorination of α-cyclohexenyl-substituted carboxylic acid derivatives

The electrochemical fluorination of α-cyclohexenyl-substituted carboxylic esters [

; R′CH₃, C₂H₅, C₃H₇)] afforded both perfluoro(9-alkyl-7-oxa-bicyclo[4.3.0]nonane)s and perfluoro(8-alkoxy-9-alkyl-7-oxabicyclo[4.3.0]nonane)s in fairly good yields. As the driving force for the ring-closure in this fluorination, a mechanism which involves a resonance stabilized intermediate radical is proposed. Perfluoro(8-chloro-8-methoxy-9-ethyl-7-oxabicyclo[4.3.0]nonane) and perfluoro(8,8-dichloro-9-ethyl-7-oxabicyclo[4.3.0]nonane) were obtained by the controlled chlorination of perfluoro(8-methoxy-9-ethyl-7-oxabicyclo[4.3.0]nonane) with anhydrous aluminum chloride in low yields. Some new fused perfluorobicyclic ethers and a perfluoroacid fluoride obtained in this experiment have been characterized by infrared, mass and ¹⁹F nmr spectra and elemental analysis.     

Reaction of pyrrolo[2,1-a]isoquinoline-2,3-diones with carbon-centered nucleophiles

Knoevenagel condensations of 5,5-dimethyl-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinoline-2,3-diones with malononitrile, ethyl cyanoacetate, indan-1,3-dione, and Drotaverine base involved the ketone carbonyl group in the former with formation of deeply colored dark blue substances. The lactam ring in the products can be opened by the action of nitrogen-centered nucleophiles, e.g., p-toluidine. The reaction of 5,5-dimethyl-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinoline-2,3-dione with methyl magnesium iodide gave 2-hydroxy-2,5,5-trimethyl-2,3,5,6-tetrahydropyrrolo[2,1-a]isoquinolin-3-one.     

Electrolytic partial fluorination of organic compounds. 64.(1) Anodic mono- and difluorination of thiazolyl sulfides

The anodic fluorination of 2-thiazolyl methyl sulfide, 2-thiazolyl propargyl sulfide, and 2-thiazolyl acetonyl sulfide was successfully carried out to provide the corresponding 5-fluorothiazole and 2,5,5-trifluorothiazoline derivatives. The latter products were readily hydrolyzed to give isolable 5,5-difluoro-2-hydroxythiazoline derivatives. On the other hand, anodic fluorination of 2-thiazolyl cyanomethyl sulfide afforded 5-fluorothiazole and alpha-fluorinated thiazole derivatives. Thus, the product selectivity was found to be greatly changed by the electron-withdrawing ability of substituents at the side chain of the thiazole ring. This is the first report of a successful anodic fluorination of a thiazole ring.     

Synthesis of perfluorobicyclic ethers

The electrochemical fluorination of cycloalkyl-substituted acetic and propionic acids were conducted to obtain several kinds of perfluorobicyclic ethers [reaction conditions: Anodic current density: 3.5 A/dm², Volt: 5～8V, Temp: 5～6 °C] . For example, from cyclopentyl-substituted acetic acids, perfluoro(4-alkyl-2-oxabicyclo[3.3.0]octane)s (I) were formed as the cyclization products in yields of 10～19% together with the corresponding perflouroalkanoyl flourides (II) (Y=3～13%).

While, perfluorospiro-ethers were obtained from the fluorination of 3-cycloalkyl-substituted propionic acids. The characterization of these perfluorobicyclic ethers which consists of the reaction with anhydrous aluminum chloride will be reported also.     

Chemistry of furanidine ketones

Catalytic cracking of 4-diazo-2, 2,5,5-tetramethylfuranid-3-one (I) in inert solvents gives the azine of 2, 2, 5,5-tetramethylfuranidine-3,4-dione (V), ketene dimer VI, and 2,2, 5, 5-tetramethylfuranidine-3,4-dione(VII). Treatment of diazoketone I with electrophilic reagents leads to replacement of the diazo group by hydroxyl and chlorine.For Parts I and II, see [1,2]     

Hydrolysis of Bis[5,5-dimethyl-3-(4-oxa-1-azoniacyclohexylidene)-1-cyclohexenyl] Sulfide Diperchlorate

Hydrolysis of bis[5,5-dimethyl-3-(4-oxa-1-azoniacyclohexylidene)-1-cyclohexenyl] sulfide diperchlorate, as well as of bis(5,5-dimethyl-3-thioxo-1-cyclohexenyl) sulfide, in the system MeCN-Et₃N yields a mixture of bis(5,5-dimethyl-3-oxo-1-cyclohexenyl) sulfide and isomeric 5,5-dimethyl-3-oxo-1-cyclohexenyl 3,3-dimethyl-5-oxo-1-cyclohexenyl sulfide. The structure of the products and their ratio were established by ¹H and ¹³C NMR and IR spectroscopy.     

Preparation and covalent hydration of 4H-imidazole derivatives

2,4,4-Trimethyl-5-phenyl-4H-imidazole, 4H-imidazole 3-oxide, and 4H-imidazole 1,3-dioxide were synthesized from 1-hydroxy-2,5,5-trimethyl-4-phenyl-3-imidazoline and 3-imidazoline 3-oxide, The action of hydrogen chloride on these compounds and on 2,4,4-trimethyl-5-phenyl-4H-imidazole 1-oxide gives products of the addition of water or alcohol — derivatives of 4-hydroxy-2-imidazolinium chlorides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1246–1251, September, 1972.     

1:1- und 1:2-Metallchelate unsulfierter o,o′-Dihydroxyazoverbindungen. Eine dünnschicht-chromatographische Untersuchung

In an earlier publication [4] the possibility of the Chromatographic separation of structurally isomeric metal chelates was mentioned; this is dealt with here in more detail. Further the separation of 1:2 mixed complexes from azo dyes and 1:2 metal-complex mixtures by thin-layer chromatography (TLC) on polyamide is described. In certain circumstances it is possible to distinguish between 1:2 metal-complex dyes with sulphonamide or alkylsulphonyl groups and those without these substituents by TLC on silica gel. The TCL methods described allow-when correctly interpreted-an unambiguous distinction between structurally isomeric metal complexes of the 1:1 and 1:2 series, and mixed complexes and mixtures of complexes of the 1:2 metal-chelate type of unsulphonated o,o′-dihydroxyazo compounds. Symmetrical o,o′-dihydroxyazo compounds, such as 2,2′-dihydroxy-5,5′-dimethylazobenzene(7), are suitable as complex-formers for heavy-metal ions, allowing the separation of the latter as their coloured chelates with aid of TLC. Structural isomers are excluded because of the molecular symmetry, so that the results are unambiguous.     

Simons electrochemical fluorination of substituted homopiperazines(hexahydro-1,4-diazepines) and piperazines

Simons electrochemical fluorination (ECF) of 1,4-dimethyl-1,4-homopiperazine, methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine was studied. For comparison, ECF of three piperazines with a N-(methoxycarbonylmethyl) group(s) was also studied. ECF of 1,4-dimethyl-1,4-homopiperazine gave a low yield of corresponding perfluoro(1,4-dimethyl-1,4-homopiperazine) together with perfluoro(2,6-diaza-2,6-dimethylheptane) as the major product. Corresponding perfluoro(homopiperazines) with mono- and/or di-(fluorocarbonyldifluoromethyl) groups [CF₂C(O)F] at the 1- and/or 4-position were formed in low yields from methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine, respectively. These new seven-membered perfluoro(1,4-dialkyl-1,4-homopiperazines) were accompanied by the formation of mono- and/or di-basic linear perfluoroacid fluorides resulting from the CC bond scission at the 2- and 3-positions of the ring. From mono- and/or di-N-(methoxycarbonylmethyl)-substituted piperazines, corresponding perfluoropeperazines having the acid fluoride group(s) were formed in low yields.     

The Condensation of Aromatic Aldehydes with Acidic Methylene Compounds in Water

The condensation of aromatic aldehydes with acidic methylene compounds such as malononitrile, methyl cyanoacetate, cyanoacetamide, 5,5-dimethyl-1,3-cyclohexanedione,bartbituric acid and 2-thiobarbituric acid proceeded very efficiently in water in the presence of triethylbenzylammonium chloride (TEBA) and the products were isolated simply by filtration.     

2-Alkylisoxazolidine-3,3-dicarboxylic acid derivatives

1,3-Dipolar cycloaddition of,-bis(alkoxycarbonyl)-N-alkylnitrones to olefins gave 2-alkylisoxazolidine-3,3-dicarboxylic acid esters, the yields of which are determined by the steric conditions and are virtually independent of the electronic effect of the substituents attached to the C=C bond of the dipolarophiles. The structures of the compounds obtained were established by analysis of the PMR spectra. The retention of the cis configuration of the substituents in the isoxazolidines obtained from maleic acid esters constitutes evidence for a one-step, four-center, concerted cycloaddition mechanism. The energy parameters for inversion of the nitrogen atom of dimethyl 2,5,5-trimethylisoxazolidine-5,5-dicarboxylate were measured.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 599–603, May, 1979.     

Preparation and properties of brominated poly(arylcarboxylate)s via interfacial polycondensation

The interfacial polycondensation method has been used for the preparation of brominated poly(arylcarboxylate)s. Brominated poly(arylcarboxylate)s can be prepared easily by mixing a solution of diacid chloride in a water-immiscible organic solvent with an aqueous alkaline solution of bisphenol in the presence of catalyst such as quaternary ammonium salts. First, in a dichloromethane-water system using triethylbenzylammonium chloride (TEBAC) as the catalyst a series of 2,2-bis(4-hydroxy-3,5-dibromophenyl)propane (3,3′,5,5′-tetrabromobisphenol A, TBBPA) with isophthaloyl (I) and terephthaloyl chlorides (T) has been prepared and some properties as inherent viscosity, solubility, crystallinity, and flammability have been measured. Copolymers prepared from TBBPA and mixed T/I with 33/67–67/33 molar ratios show good solubility and amorphous nature, and can be cast into transparent and tough films with limiting oxygen index of 58–59 (ANSI/ASTM D2683-77). Second, the effects of some variables as the nature of organic phase and catalysts, concentration of reactants, and basicity of aqueous phase on the interfacial polycondensation of TBBPA with equal parts of T and I [T/I (50/50)] was investigated in some detail. Among the solvents tested dichloromethane was found to be the best solvent and quaternary ammonium salts such as TEBAC and tetra-n-butylammonium bromide (TBAB) were highly efficient catalysts. Poly(arylcarboxylate)s with the highest molecular weights were obtained at an acid chloride concentration of 0.2 mol/L in dichloromethane and a concentration of TBBPA of 0.1 mol/L in alkali when TEBAC was used as catalyst. A maximum of inherent viscosity was obtained at two equivalent amounts of alkali corresponding to bisphenol. Polycondensation of several combinations of T/I (50/50) with some other tetrabromobisphenols, such as 3,3′,5,5′-tetrabromo-4,4′-biphenol, 3,3′,5,5′-tetrabromobisphenol S, 3,3′,5,5′-tetrabromo-4,4′-thiodiphenol, and 3,3′,5,5′-tetrabromophenolphthalein, were carried out with limited success. Whereas, a more favorable result could be obtained by the mixed copolycondensation of these tetrabromobisphenols and bisphenol A (BPA) with T/I (50/50). Finally, the copoly(arylcarboxylate)s from TBBPA, BPA, T, and I were prepared and characterized. The incorporation of bromine on the polymer backbone caused a decrease of inherent viscosity, glass transition temperature, crystallinity, and thermal stability of copolyarylates, whereas it caused a great enhancement of flame retardancy.     

Reaktive E=C(p‐p)π‐Systeme. 54 [1] Reaktionen des Perfluor‐2‐arsapropens,F3CAs=CF2 (1), mit H‐aciden Verbindungen Me2EH (E = N,P, As) und MeE′H (E′ = O,S, Se)

Reactive E=C(p‐p)π‐Systems. 54 [1] Reactions of perfluoro‐2‐arsapropene, F₃CAs=CF₂ (1), with H‐acidic compounds Me₂EH (E = N, P, As) and MeE′H (E′ = O, S, Se) The reactions of the perfluoro‐2‐arsapropene ( 1 ) with H‐acidic compounds Me₂EH (E = N, P, As) and MeE′H (E′ = O, S, Se), respectively, proceed via addition to the As=C double bond yielding either secondary arsanes F₃C(H)AsCF₂X (X = NMe₂, PMe₂, OMe, SMe) or AsX derivatives (X = AsMe₂, SeMe). Me₂‐AsH is obviously a border case nucleophile because, besides the AsX derivative as main product, small amounts of the arsane are formed indicative for the reverse addition pathway. With the strong base Me₂NH, the addition is followed immediately by HF elimination producing the fairly stable arsaalkene F₃CAs=C(F)NMe₂ ( 4 ) which had already been obtained by reaction of HAs(CF₃)₂ with three equivalents of Me₂NH. The novel rather labile compounds were identified by spectroscopic (NMR, GC/MS) investigations. – Quantum chemical DFT calculations [B3LYP/6‐311+G(d,p)] were carried out to determine the relative energy of the isomeric products and the thermodynamics of the addition reactions.     

Quantification of the 35S promoter in DNA extracts from genetically modified organisms using real-time polymerase chain reaction and specificity assessment on various genetically modified organisms, part I: operating procedure

A highly sensitive quantitative real-time assay targeted on the 35S promoter of a commercial genetically modified organism (GMO) was characterized (sF/sR primers) and developed for an ABI Prism 7700 Sequence Detection System and TaqMan chemistry. The specificity assessment and performance criteria of sF/sR assay were compared to other P35S-targeted published assays. sF/sR primers amplified a 79 base pair DNA sequence located in a part of P35S that is highly conserved among many caulimovirus strains, i.e., this consensus part of CaMV P35S is likely to be present in many GM events. According to the experimental conditions, the absolute limit of detection for Bt176 corn was estimated between 0.2 and 2 copies of equivalent genome (CEG). The limit of quantification was reached below 0.1% Bt176 content. A Cauliflower Mosaic Virus control (CaMV) qualitative assay targeted on the ORF III of the viral genome was also used as a control (primers 3F/3R) to assess the presence of CaMV in plant-derived products. The specificity of this test was assessed on various CaMV strains, including the Figwort Mosaic Virus (FMV) and solanaceous CaMV strains. Considering the performance of sF/sR quantification test, the highly conserved sequence, and the small size of the amplicon, this assay was tested in a collaborative study in order to be proposed as an international standard.     

Synthesis of isoquinoline derivatives of quinoxalin-2-one from pyrrolo[2,1-a]isoquinoline-2,3-diones and o-phenylenediamine

Reactions of 5,5-dialkyl-2,3,4,5-tetrahydropyrrolo[2,1-a]isoquinoline-2,3-diones with o-phenylenediamine in the presence of a catalytic amount of hydrogen chloride or p-toluenesulfonic acid involved opening of the pyrrole ring with formation of 3-(3,3-dialkyl-1,2,3,4-tetrahydroisoquinolin-1-ylidenemethyl)quinoxalin-2(1H)-ones. The presence of an enamine fragment in the products was confirmed by reaction with oxalyl chloride.     

Heterocyclic analogs of pleiadiene. 41. synthesis of 2-perfluoroalkyl-perimidines

2-perfluoroalkylperimidines were obtained by the action of trifluoroacetic anhydride and perfluoro carboxylic acid chlorides on 1,8-naphthalenediamine and its N-substituted derivatives. N,N-Diacyl-1,8-naphthalenediamines (in the case of unsubstituted 1,8-naphthalenediamine) and 6(7)-perfluoroacyl-2-perfluoroalkylperimidines (in the case of N-substituted 1,8-naphthalenediamines) were isolated as side products.See [1] for communication 40.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 413–417, March, 1979.     

Synthesis and characterization of novel aromatic polyamides with polyalicyclic cardo groups

5,5-Bis[4-(4-carboxyphenoxy)phenyl]hexahydro-4,7-methanoindan ( 3a ) and 5,5-bis[4-(4-aminophenoxy)phenyl]hexahydro-4,7-methanoindan ( 3b ) were prepared in two main steps starting from the aromatic nucleophilic halogen-displacement of p-fluorobenzonitrile and p-chloronitrobenzene, respectively, with 5,5-bis(4-hydroxyphenyl)hexahydro-4,7-methanoindan in the presence of potassium carbonate in N,N-dimethylformamide (DMF). Using triphenyl phosphite and pyridine as condensing agents, two series of polyamides having polyalicyclic cardo units were directly polycondensated from dicarboxylic acid 3a with various aromatic diamines, or from diamine 3b with various aromatic dicarboxylic acids in the N-methyl-2-pyrrolidone (NMP) solution containing dissolved calcium chloride. High molecular weight polyamides with inherent viscosities between 0.73 and 1.44 dL/g were obtained. All polymers were readily soluble in polar aprotic solvents such as NMP and N,N-dimethylacetamide (DMAc) and afforded transparent, flexible, and tough films by solution casting. The glass-transition temperatures (T_g) of these aromatic polyamides were in the range of 219–253°C by DSC, and the 10% weight loss temperatures in nitrogen and air were above 467 and 465°C, respectively. A comparative study of some polyamides with an isomeric repeat unit is also presented. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4510–4520, 1999     

The mass spectra of some methyl norbornyl chlorides

The mass spectra of exo-2-norbornyl chloride, 1- and 2-methyl exo-2-norbornyl, exo-camphenilyl, apoisobornyl, bornyl and isobornyl chloride, and camphene hydrochloride, α- and β-fenchyl chloride and fenchene hydrochloride, and exo-isofenchyl chloride and 2,5,5-trimethyl exo-2-norbornylchloride, and camphene and α-fenchene have been examined at 12 to 16 and 80° eV and at 30 to 49 and 80°, or higher temperatures. Wagner-Meerwein rearrangements occur very readily in the ion source and compounds related by these rearrangements give very similar fragmentation patterns. Thermal decompositions are important with the tertiary chlorides especially at higher source temperatures. The rates of methanolysis of some of these chlorides were measured.     

Synthesis and reactions of 5-aryl-2-thiophenecarbaldehydes

The reaction of 2-thiophenecarbaldehyde with arene diazonium chlorides in the presence of CuCl₂ catalyst gave 5-aryl-2-thiophenecarbaldehydes. Use of 4-nitrobenzene diazonium chloride in the reaction also gave the isomeric 3-(4-nitrophenyl)-2-thiophenecarbaldehyde. Condensation products of the 5-aryl-2-thiophenecarbaldehydes with cyanoacetic acid esters, cyanoacetamide, and with barbituric and dimethylbarbituric acids were prepared. Communication 16 in the series “Synthesis of heterocycles based on the products of arylation of unsaturated compounds”. For Communication 15 see [1]. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1166–1171, August, 2008.     

Reaktion von α-Chlorpropionyl-chlorid mit Triäthylamin Bildung eines Säurechlorid-enolesters

Previous and new data are interpreted to mean that the two isomeric products C₆H₇Cl₃O₂ obtained by the selfcondensation of α-chloropropionyl chloride (I) in the presence of about 0.5 moleequivalent triethyl amine are acid chloride enolesters, namely cis- and trans-1. 2-dichloropropenyl-α-chloropropionate (VIII). Similarly, dichloroacetyl chloride (X) was converted to trichlorovinyl-dichloroacetate (XI).