Synthesis of Heterocyclic Compounds Containing Perfluoroalkyl Groups. Reactions of Perfluoro(2-methyl-2-pentene) and Perfluoro(5-aza-4-nonene) with N,S-Dinucleophiles

Perfluoro(2-methyl-2-pentene) and perfluoro(5-aza-4-nonene) react with 1,4,5,6-tetrahydropyrimi-dine-2-thiol, pyridine-2-thiol, and 1,2,4-triazole-3-thiol to afford fused heterocyclic systems, while their reactions with tetrahydrothiazole-2-thione and pyrimidine-2-thiol result in replacement of the fluorine atom at the double bond. Treatment of 3,3,3-trifluoro-1-pentafluoroethyl-2-trifluoromethyl-1-pentenyl isothiocyanate with ammonia gives N-(3,3,3-trifluoro-1-pentafluoroethyl-2-trifluoromethyl-1-propenyl)thiourea which undergoes ring closure to 4-tetrafluoroethylidene-5,5-bis(trifluoromethyl)-4,5-dihydrothiazol-2-amine. Possible cyclization paths and the effect of the 1,3(N,S)-dinucleophile nature on the direction of nucleophilic addition at the double bond are discussed.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 3, 2005, pp. 441–446.Original Russian Text Copyright © 2005 by Furin, Zhuzhgov.     

Solvolyis reactions of perfluoro-5-aza-4-nonene, C3F7CFNC4F9

Hydrolysis of the imine perfluoro-5-aza-4-nonene, C₃F₇CFNC₄F₉, in ether was studied by several spectroscopic techniques including NMR. The initial product is C₃F₇CONHC₄F₉ which is converted to (C₃F₇CO)₂NH and then to C₃F₇CONH₂ and C₃F₇CO₂H. Solvolysis in liquid ammonia afforded the amidine C₃F₇C(NH)NH₂. Reaction with hydrazine produced 3,5-bis(heptafluoropropyl)-1,2,4-triazole whose crystal structure is reported.     

Reaktionen vonN-Sulfinylverbindungen mit dem 1,2,4-Trithia-3,5-diborolan-Ringsystem und Substitutionsreaktionen am 1,2,4-Trithia-3,5-diborolan und 1,2-Dithia-4-aza-3,5-diborolidin

The reaction of trimethylsilyl- and pentafluorophenyl-N-sulfinylamine respectively with 3,5-dihalogeno-1,2,4-trithia-3,5-diborolanes yields the 1,2-dithia-4-aza-3,5-diborolidines1-3.Tert-butyl-N-sulfinylamine and 3,5-dimethyl-1,2,4-trithia-3,5-diborolane react analogous. OtherN-sulfinylamines however split the disulfane bridge in 3,5-dimethyl-1,2,4-trithia-3,5-diborolane and the 1,4-dithia-2-aza-3,5-diborolidines5A-7(A) are formed. Besides of boroxines, cyclo-2,4,6-trimethyl-1,3-dioxa-5-aza-2,4,6-triboranes and cyclo-2,4,6-trimethyl-1-oxa-3,5-diaza-2,4,6-triboranes are formed as byproducts,8–10 have been isolated. In 1,2,4-trithia-3,5-diborolanes and 1,2-dithia-4-aza-3,5-diborolidines the bromo-atoms can be substituted by alkyl (13, 14), by amino (15–20) and by isothiocyanato groups. The compounds were characterised analytically and spectroscopically (MS; NMR:¹H,¹¹B,¹⁹F,²⁹Si; IR).

     

5-Amino-1,2,3,4-thiatriazole: Its acylation with chloroformates and chlorothioformates as a route to 1,2,4-thiadiazoles and 1,6,6a,Δ4-trithia-3,4-diazapentalenes

Summary Pyridine catalyzed acylation of 5-amino-1,2,3,4-thiatriazole with chloroformates and chlorothioformates afforded 3,5-bis(ethoxycarbonylamino)-1,2,4-thiadiazoles in the former and 2,5-bis(phenoxy)-1,6,6a,⁴-trithia-3,4-diazapentalenes in the latter case. An unstable, but isolable intermediate 2-phenoxy-1-aza-3,4-dithiolium-5-imide has been found if the chlorothioformate acylation was performed in acetonitrile in the absence of pyridine. The bis(phenoxy)trithiapentalenes are prone to nucleophilic displacement reactions at positions 2 and 5, exchanging in a stepwise manner one or both phenoxy groups. The structures of the compounds described could be inferred from their¹H-NMR¹³C-NMR, and mass spectra and were corroborated by the comparison with the data of authentic and similar derivatives as well as by chemical means.

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Die Acylierung von 5-Amino-1,2,3,4-thiatriazol mit Chlorformiaten und Chlorthioformiaten als Route zu 1,2,4-Thiadiazolen und 1,6,6a,⁴-Trithia-3,4-diazapentalenen

Zusammenfassung Die durch Pyridine katalysierte Acylierung von 5-Amino-1,2,3,4-thiatriazol mit Chlorameisensäureethylester führt zu 3,5-bis-(ethoxycarbonylamino)-1,2,4-thiadiazolen, während mit Chlorthioameisensäureethylester 2,5-bis(phenoxy)-1,6,6a,⁴-trithia-3,4-diazapentalene erhalten werden. Ohne Pyridin entsteht bei letzterer Reaktion ein wenig stabiles, aber isolierbares Zwischenprodukt: 2-Phenoxy-1-aza-3,4-dithiolium-5-imid. Die Bis(phenoxy)trithiadiazapentalene reagieren leicht mit nukleophilen Reagenzien und tauschen dabei schrittweise eine oder beide Phenoxygruppen aus.

     

Cycloaddition reactions of 2,3-dihydro-1H-1,4-diazepines with nitrile oxides and imines. Synthesis of bis[1,2,4]oxadiazolo-and bis[1,2,4]triazolo[1,4]diazepine derivatives

New heterotricyclic systems, 6,10a,11,11a-tetrahydro-5H-bis[1,2,4]oxadiazolo[4,5-d:5′,4′-g][1,4]diazepines 6,7,9-11 and 5,6,10,10a,11,11a-hexahydro-1H-bis[1,2,4]triazolo[4,3-d:3′,4′-g][1,4]diazepines 8,12 have been obtained by double site- and regie-specific 1,3-dipolar cycloaddition of mesitylnitrile oxide ( 1 ) or diphenylnitrile imine ( 2 ) to 5,7-disubstituted 2,3-dihydro-1H-1,4-diazepines 3-5. The structure of the synthesized bis-adducts 6-12 shows that the hetero double bonds are much more reactive than the olefinic ones in the dipolarophiles under study. No evidence for the formation of mono-adducts was obtained.     

Reactivity of 3,5-bis-(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-triazole

Alkylation of 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-triazole with haloalkanes afforded N-CH₂R derivatives, and nitration furnished the corresponding bis-N-nitramine isolated as a trisodium salt. Treatment of the latter with CH₃I resulted in denitration. Diazotization and oxidation of 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4- triazole, its N-methyl and N-carboxy derivatives gave rise to the corresponding azido and nitro derivatives. Salts of 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-triazol-5-acetic acid with nitrogen-containing bases were synthesized. It was established that the character of reaction products of 3,5-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,4-triazole with formaldehyde depended on the acid-base properties of the medium.__________Translated from Zhurnal Organicheskoi Khirmii, Vol. 41, No. 2, 2005, pp. 270–276.Original Russian Text Copyright © 2005 by Sergievskii, Romanova, Mel’nikova, Tselinskii.     

Decoupling optical and potentiometric band gaps in pi-conjugated materials

Syntheses, optical spectroscopy, potentiometric studies, and electronic structural calculations are reported for two classes of conjugated (porphinato)metal oligomers that feature a meso-to-meso ethyne-bridged linkage topology. One set of these systems, bis[(5,5'-10,20-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]ethyne (DD), 5,15-bis[[5'-10',20'-bis[3,5-di(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]ethynyl]-10,20-bis[3,5-di(9-methoxy-1,4,7-trioxanonyl)phenyl]porphinato)zinc(II) (DDD), and 5,15-bis[[15' '-(5'-10',20'-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]-[(5' '-10' ',20' '-bis[3,5-di(9-methoxy-1,4,7-trioxanonyl)phenyl]porphinato)zinc(II)]ethyne]ethynyl]-10,20-bis[3,5-di(9-methoxy-1,4,7-trioxanonyl)phenyl]porphinato)zinc(II) (DDDDD), constitute highly soluble analogues of previously studied examples of this structural motif having simple 10,20-diaryl substituents, while a corresponding set of conjugated oligomers, [(5-10,20-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]-[(5'-15'-ethynyl-10',20'-bis[10,20-bis(heptafluoropropyl)porphinato)zinc(II)]ethyne (DA), 5,15-bis[[5'-10',20'-bis[3,5-di(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]ethynyl]-10,20-bis(heptafluoropropyl)porphinato]zinc(II) (DAD), and 5,15-bis[[15' '-(5'-10',20'-bis[3,5-bis(3,3-dimethyl-1-butyloxy)phenyl]porphinato)zinc(II)]-[(5' '-(10' ',20' '-bis(heptafluoropropyl)porphinato)zinc(II)]ethyne]ethynyl]-10,20-bis[3,5-di(9-methoxy-1,4,7-trioxanonyl)phenyl]porphinato)zinc(II) (DADAD), features alternating electron-rich and electron-poor (porphinato)zinc(II) units. Electrooptic and computational data for these species demonstrate that it is possible to engineer conjugated oligomeric structures that possess highly delocalized singlet (S1) excited states yet manifest apparent one-electron oxidation and reduction potentials (E1/20/+ and E1/2-/0 values) that are essentially invariant with respect to those elucidated for their constituent monomeric precursors.     

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.     

Conversion of 4-amino-4H-1,2,4-triazole to 1,3-bis(1H-azol-l-yl)-2-aryl-2-propanols and 1-phenacyl-4-[(benzoyl or 4-toluenesulfonyl)-imino]-(1H-1,2,4-triazolium) Ylides

A series of 1,3-bis(1H-azol-1-yl)-2-aryl-2-propanols 17 were synthesized in an one-pot procedure by reacting l-aryl-2-(1H-1,2,4-triazol-l-yl)- or l-aryl-2-(1H-imidazol-l-yl)ethanones with dimethylsulfoxonium methide in the presence of either 1,2,4-triazole or imidazole. The aromatic groups in 17 were either 4-bromo-, 4-chloro-, 2,4-dichloro- or 2,4-difluorophenyl. 4-Amino-4H-1,2,4-triazole was acylated with either benzoyl or 4-toluene-sulfonyl chloride to afford [4-(benzoyl or 4-toluenesulfonyl)amino]4H-1,2,4-triazole. Subsequent alkylations with 4-bromo- or 4-chlorophenacyl bromide produced 1-(4-bromo- or 4-chlorophenacyl)-4-[(benzoyl- or 4-toluenesulfonyl)amino]-1H-1,2,4-triazolium bromides. Neutralizations of these salts provided the corresponding ylides.     

Guanidine in the synthesis of perfluoroalkylpyrimidines and perfluoroalkyl-s-triazines

Perfluoro-2-methylpent-2-ene and perfluoro-5-azanon-4-ene react with guanidine hydrochloride in the presence of triethylamine to give 2-amino-6-fluoro-4-pentafluoroethyl-5-trifluoromethylpyrimidine and 2-amino-4,6-bis(heptafluoropropyl)-1,3,5-triazine, respectively. The structure of the former product was confirmed by X-ray diffraction analysis.     

Synthesis and Molluscicidal Activity of Phosphorus-Containing Heterocyclic Compounds Derived from 5,6-Bis (4-bromophenyl)-3-hydrazino-1,2,4-triazine

Novel N¹-(phosphoryl moiety)-N²-(1,2,4-triazin-3-yl)hydrazines 4, 6, 8, 9 and 12, iminophosphorane 3, iminophosphane 5, 1,2,4-triazinyldiazaphospholine 7, 1,2,4,3-triazaphospholinotriazines 2, 10, 11, and 1,2,4-triazino[3,2-c][1,2,4,5] triazaphosphine 13 have been obtained via treatment 5,6-bis(4-bromophenyl)-3-hydrazino-1,2,4-triazine (1) with various polyfunctional phosphorus reagents by stirring at room temperature or refluxing for long time in tetrahydrofuran. Structures of these compounds have been deduced upon the basis of elemental and spectral data. Molluscicidal activity of the prepared compounds against Biomphalaria Alexandrina snails (the intermediate host of Schistosoma mansoni) showed considerable activities.     

Syntheses,crystal structures and antibacterial activities of two new Mn(II) complexes based on triaryltriazoles

Two new Mn(II) complexes, trans-[Mn(L1-L2)₂(NCS)₂] (1–2) with triaryltriazole (1, L1 = 3-(p-bromophenyl)-4-phenyl-5-(2-pyridyl)-1,2,4-triazole; 2, L2 = 3,4-bis(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole), have been synthesized and structurally characterized by elemental analysis, FT-IR, ESI-MS, and single-crystal X-ray crystallography. Crystallographic studies revealed that both 1 and 2 contain a distorted octahedral [MnN₆] core with two trans-disposed NCS^? ions. The L1 ligand, 1 and 2, together with four known homologous Mn(II) complexes, trans-[Mn(L3-L6)₂(NCS)₂] (3–6) (3, L3 = 3-(p-methoxyphenyl)-4-(p-chlorophenyl)-5-(2-pyridyl)-1,2,4-triazole; 4, L4 = 3-(p-methoxyphenyl)-4-(p-bromophenyl)-5-(2-pyridyl)-1,2,4-triazole; 5, L5 = 3-(p-chlorophenyl)-4-(p-methylphenyl)-5-(2-pyridyl)-1,2,4-triazole; 6, L6 = 3,5-bis(2-pyridyl)-4-(p-methylphenyl)-1,2,4-triazole), were tested in vitro for their antibacterial activities against two Gram-positive bacterial strains and two Gram-negative bacterial strains by the MTT method. The results indicate that 1 exhibited better activity than Penicillin and Kanamycin against Pseudomonas aeruginosa and also better than its free L1 ligand.     

Expansion of the pentafluorobenzene ring and other skeletal transformations in the reaction of perfluoro(1,2-diethyl-1-phenyl-1,2-dihydrocyclobutabenzene) with antimony pentafluoride

The reaction of perfluoro(1-phenyl-1,2-diethyl-1,2-dihydrocuclobutabenzene) with SbF5 at 20°C, followed by treatment of the reaction mixture with water gave perfluoro {4-[1-(2-propylphenyl)propylidene]-2,5-cyclohexadien-1-one} together with perfluoro[4b,10-diethylbenzo[a]azulen-7(4bH)-one] resulting from unusual expansion of the pentafluorobenzene ring to seven-membered ring. Analogous reaction at 90°C, apart from the above compounds, afforded perfluorinated 10-ethyl- and 3,10-diethylbenzo[a]azulen-6(10H)-ones via elimination of C₂F₅ group from the seven-membered ring or its migration to the benzene ring.     

Regioselective Synthesis of Substituted Triazolium Salts <Emphasis Type="Italic">via</Emphasis> 1,3-Dipolar Cycloaddition Reactions

Summary. The regioselectivity of 1,3-dipolar cycloaddition reactions of 1-aza-2-azoniaallene salts with ,-unsaturated nitriles such as acrylonitrile or cyclohexylidene acetonitrile afforded only 1,2,4-triazolium salts via addition to the nitrile group, while the other expected pyrazolium salts were not observed. Moreover, 1-aza-2-azonia-allene salts reacted with other competitive systems such as -iminonitrile derivatives yielding only triazolium salts via addition to the nitrile and not to the imino group. Treatment of cumulene with 3-pyridylnitrile afforded the pyridinium salt. However, 2,3-dimethyl-5-(2,6-dimethoxyphenyl)-[1,2,4]triazole could be prepared from cumulene and 2,6-dimethoxybenzonitrile. Some reactions of nitriles with 1-aza-2-azonia-allene salts prepared from 1,2,3-indantrione and 9-acetylphenanthrene are discussed.     

Regioselective Synthesis of Substituted Triazolium Salts via 1,3-Dipolar Cycloaddition Reactions

The regioselectivity of 1,3-dipolar cycloaddition reactions of 1-aza-2-azoniaallene salts with ,-unsaturated nitriles such as acrylonitrile or cyclohexylidene acetonitrile afforded only 1,2,4-triazolium salts via addition to the nitrile group, while the other expected pyrazolium salts were not observed. Moreover, 1-aza-2-azonia-allene salts reacted with other competitive systems such as -iminonitrile derivatives yielding only triazolium salts via addition to the nitrile and not to the imino group. Treatment of cumulene with 3-pyridylnitrile afforded the pyridinium salt. However, 2,3-dimethyl-5-(2,6-dimethoxyphenyl)-[1,2,4]triazole could be prepared from cumulene and 2,6-dimethoxybenzonitrile. Some reactions of nitriles with 1-aza-2-azonia-allene salts prepared from 1,2,3-indantrione and 9-acetylphenanthrene are discussed.     

Structure-Property Relationship in Bispyrrolizidine Photochromic Compounds Derived from Indolo[4,5-<Emphasis Type="Italic">e</Emphasis>]- and -[7,6-<Emphasis Type="Italic">g</Emphasis>]indoles

The spirocyclic compounds bis[2′,3′-bis(methoxycarbonyl)-5′,6′,6′ -trimethylspirofluoren-9,4′-(1′-aza-2′-cyclopentene)][1′,5′ -a]indolino[4,5-e]indoline and bis[2-,3′-bis(methoxycarbonyl)-5′,6′,6′ -trimethylspiro-fluoren-9,4′-(1′-aza-2′-cyclopentene)][1′,5′ -a]indolino[7,6-g]indoline exhibit photochromic properties with various half-lifes. The AM1 method was used to correlate the structural and electronic properties, on the one hand, and photochromic properties, on the other, and to explain reasons for the difference in the photochromism of the two compounds.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 4, 2005, pp. 670–673.Original Russian Text Copyright © 2005 by Samsoniya, Trapaidze, Tsikoliya, Machaidze, Esakiya.     

Mass spectra of some perfluoroalkyl and perfluoroalkylether substituted 1,2,4-oxadiazoles

Electron impact fragmentation patterns were obtained for 1,4-bis[(5-perfluoro-n-heptyl)-1,2,4-oxadiazolyl]-benzene, its perfluoroalkylether substituted analogue, 3,5-bis(perfluoroalkyl)-, 3,5-bis(perfluoroalkylether)- and 3-perfluoroalkylether-5-perfluoroalkyl-1,2,4-oxadiazoles. In the compounds containing the phenylene group the molecular ion constituted the base peak; the main process was the breakdown of the oxadiazole ring with concurrent liberation of the perfluoroalkyl or perfluoroalkylether nitrile molecule; cleavage of the fluorinated chain α to the oxadiazole ring was found to take place to a considerable degree. In the perfluorinated 1,2,4-oxadiazoles cleavage β to the oxadiazole ring occurred preferentially; fragmentation of the ring itself took place to a limited degree only. The 3-perfluoroalkylether-5-perfluoroalkyl-1,2,4-oxadiazole appeared to undergo the primary β-cleavage exclusively at the perfluoroalkylether sidechain.     

Chiral 1,2,4-triazoles: stereoselective acylation and chlorination

Acyl groups are transferred from diverse N- and O-acyl derivatives of chiral 3,5-bis-(1-hydroxyethyl)-[1,2,4]-triazole to amino acid esters enantioselectively, with 7% to 68% ee, depending on the temperature conditions and nature of the reagents. Thionyl chloride replaced the hydroxyl groups of (S)-1-[4-amino-5-((S)-1-hydroxy-ethyl)-[1,2,4]-triazol-3-yl]-ethanol 3 stereospecifically with inversion, as confirmed by X-ray analysis, which also revealed unusual crystal structures with asymmetric units comprising three molecules of 4-amino-3,5-bis(R-1-chloroethyl)-1,2,4-triazole 5 and four of 3,5-bis((R)-1-chloroethyl)-1H-1,2,4-triazole 6.     

Electrophilic Additions to Strained Bridgehead Olefins. Estimation of Strain by Comparison with the Solvolysis of Bridgehead Bromides

The addition of water, acetic acid, and hydrogen bromide to the strained bridge-head olefins bicyclo[3.3.1]-1(2)-nonene (1) , bicyclo[4.2.1]-1(8)-nonene (2) , and bicyclo[4.2.1]-1(2)-nonene (3) gives exclusively the bridgehead alcohols, acetates, and bromides, respectively. The reaction rate constants for the addition of acetic acid to the bridgehead olefins 1,2 and 3 , and the solvolysis rates for the related 1-bromo-bicyclo[3.3.1]nonane (4) and 1-bromobicyclo[4.2.1]nonane (5) were measured. A comparison of the activation enthalpies of these two reactions gives an estimate of relative strain of the bridgehead double bond. The strain in the bicyclo[4.2.1]nonenes 2 and 3 is similar to that in trans-cyclooctene (8-9 kcal/mol).     

The Synthesis of Strained Methylene-bridged Bicyclic Olefins by the Intramolecular Wittig Reaction

A convenient synthesis of the strained methylene-bridged trans-cyclooctenes bicyclo[3.3.1]-1 (2)-nonene (1) , bicyclo[4.2.1]-1(8)-nonene (2) , and bicyclo[4.2.1]-1(2)-nonene (3) by the intramolecular Wittig reaction is described (see Schemes 1–4). The (3-oxocycloalkyl)alkyl-phosphonium bromides 20 , 27 and 38 undergoing cyclization to the bridgehead olefins are formed by simple reaction sequences. The spectral properties (IR., ¹H-NMR., ¹³C-NMR., and UV.) of the olefins are discussed with regard to their strain.