Peculiarities of the nitration of secondary polynitroalkanes

Conclusions In the interaction of salts of 1,1,1,3,5,5,5-heptanitro- or 1,5-difluoro-1,1,3,5,5-pentanitropentanes with nitrating systems based on HNO₃, 1,1,1,3,3,5,5,5-octanitro- or 1,5-difluoro-1,1,3,3,5,5-hexanitropentanes, 1,1,1,5,5,5-hexanitro- or 1,5-difluoro-1,1,5,5-tetranitropentan-3-ones, the O-bis-(2,2,2-trinitroethyl)nitromethyl ether of bis(2,2,2-trinitroethyl)carboxime or the O-bis(2-fluoro-2,2-dinitroethyl)nitromethyl ether of bis(2-fluoro-2,2-dinitroethyl)carboxime are formed. The ratio of the reaction products depends on the composition of the nitrating system. The data obtained permit us to consider that the nitrating reagent is a nonionized form of HONO₂ or AcONO₂.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1357–1361, June 1986.     

O-α-nitroalkyl oximes of 1,5-disubstituted 1,1,5,5-tetranitro-pentan-3-ones

Conclusions The salts and the corresponding nitronic acids of 1,5-disubstituted 1,1,3,5,5-pentanitropentanes are converted, by the action of strong acids, to the 0--nitroalkyl oximes of 1,5-disubstituted 1,1,5,5-tetranitropentan-3-ones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2737–2739, December, 1985.     

Studies on olefin isomerization catalyzed by transition metals: Part IV. Isomerization of 1,5-cyclooctadiene catalyzed by (R-Cp)2TiCl2/R'MgX systems

The isomerization of 1,5-cyclooctadiene (1,5-COD) to 1,4-COD and 1,3-COD catalyzed by (R-Cp)₂TiCl₂ (Cp = η⁵-C₅H₅)/R'MgX systems was studied. Cp₂TiCl₂/i-C₃H₇MgBr was found to have excellent catalytic activity for the isomerization of 1,5-COD to 1,3-COD at room temperature. The effects of solvent, Ti/Mg ratio, peroxide content in 1,5-COD, substituents on the cyclopentadienyl ligand of (R-Cp)₂TiCl₂, and alkyl groups in the Grignard reagents were examined and a titanium hydride addition-elimination mechanism was proposed.     

On Triazoles. XXXII. The reaction of 5-amino-1 H-1,2,4-triazolylcarbothiohydrazides with β- and γ-oxo-esters

5-Amino-lH-1,2,4-triazolylcarbothiohydrazides gave β and γ-oxo-esters in boiling ethanol [1,2,4]triazolo- [1,5-d][1,2,4,6]tetrazepine-5-thiones 3 . Analogously ethyl 2-oxocyclohexanecarboxylate provided a mixture of two diastereomeric spiro derivatives 5 and 6 . At 130°, 2-acetonyl-5-methyl-4,5-dihydro-1,3,4-oxadiazole-5-thione ( 8 ) was formed. Ring closure of 3e (R¹ = CH₃, R² = CH₂CH₂COOEt, Q = morpholino) lead to the isomeric pyrrolo[2,1-g][1,2,4]triazolo[1,5-d][1,2,4,6]tetrazepin-8(11H)-one ( 12 ) and pyrrolo[1,2-f][1,2,4]triazolo-[1,5-d][1,2,4,6]tetrazepin-10(7H)-one ( 13 ) derivatives representing two new ring systems.     

Aminoazoles in Heterocycles Synthesis: II. Trifluoromethyl-containing Diketones in the Synthesis of Pyrazolo[1,5-a]pyrimidines

A regioselective synthesis was carried out of 7-trifluoromethylpyrazolo[1,5-a]pyrimidines by reaction of 3(5)aminopyrazoles with 1,3-diketones containing CF₃ group. The characteristic chemical shifts were established for C⁵ and C⁷ atoms of the pyrimidine ring and of substituents thereof in the ¹H, ¹³C, and ¹⁹F NMR spectra of pyrazolo[1,5-a]pyrimidines.     

Phosphorus-Nitrogen Compounds: The Reactions of Hexachlorocyclotriphosphazatriene with Pentane-1,5-Diol. Nuclear Magnetic Resonance Studies of The Products

Abstract

From the reactions of hexachlorocyclotriphosphazatriene, N₃P₃Cl₆ (1) with pentane-1,5-diol (2) in dichloromethane solution, the following derivatives have been isolated: 2,2-spiro(1′,5′-pentanedioxy)-4,4,6,6-tetrachlorocyclotriphosphazatriene, N₃P₃Cl₄[O(CH₂)₅O] (3); its ansa isomer, 1,3-ansa(1′,5′-pentanedioxy)-1,3,5,5-tetrachlorocyclotriphosphazatriene, (4); bis spiro(1′,5′-pentanedioxy)-6,6-dichlorocyclotriphosphazatriene, N₃P₃Cl₂[O(CH₂)₅O]₂ (5); its spiro-ansa isomer, (1′,5′-pentanedioxy)-1,3-dichlorocyclotriphosphazatriene (6); as well as the bino(1,5-pentanedioxy)-di-(pentachlorocyclotriphosphazatriene), N₃P₃Cl₅ [O(CH₂)₅O]N₃P₃Cl₅ (7), and tri-bino(1,5-pentanedioxy)-di (trichlorocyclotriphosphazatriene), N₃P₃Cl₃[O(CH₂)₅O]₃N₃P₃Cl₃, (8) derivatives. Their structures were established by MS and NMR with the use of ¹H, ¹³C, and ³¹P spectroscopy. Product types and relative yields are compared with those of the previously investigated diol derivatives. The yield of the mono-ansa product (25%) obtained in this system was considerably increased relative to those of the propane-1,3-diol derivative (11.2%) and decreased relative to the 2,2-dimethyl-propane-1,3-diol (36.2%), and bis(2-hydroxyethyl) ether (34.5%) derivatives.     

Synthese von [1,2,4]Triazolo [1,5-a]chinazolinen. Ableitung der Konformation von Substituenten mit Hilfe der 13C-NMR.-Spektroskopie

Synthesis of [1,2,4]Triazolo[1,5-a]quinazolines. Assignment of the Conformation of Substituents with the Aid of ¹³C-NMR. Spectroscopy The synthesis of [1,2,4]triazolo[1,5-a]quinazolines by condensation of 2-hydrazinobenzoic acid with N-cyano-imidates is reported. The preferred conformation of substituents at C (5), e.g. N (CH₃)₂, N (CH₃)NH₂, N (CH₃)OH, relative to the aromatic system is deduced with the aid of ¹³C-NMR. chemical shifts and proton nuclear Overhauser effect experiments.     

Polynuclear heterocyclic systems based on naphthalene-1,5-diol: I. Reaction of naphthalene-1,5-diol and its derivatives with β-dicarbonyl and α,β-unsaturated carbonyl compounds

Reactions of naphthalene-1,5-diol and its derivatives (5-methoxynaphthalen-1-ol, 2-bromo-5-methoxynaphthalen-1-ol, and 2,6-di-tert-butylnaphthalene-1,5-diol) with ethyl acetoacetate, acetylacetone, and p-methoxycinnamic acid under acidic conditions (HCl, HClO₄, CF₃CO₂H) gave substituted benzo[h]-chromenes, naphtho[1,2-b]pyrylium salts, and 3,4-dihydrobenzo[h]chromenes, respectively. Possible mechanisms were proposed for the observed acid-catalyzed heterocyclizations.     

The molecular and supramolecular structures of four 1,5,6,10b‐tetrahydropyrazolo[1,5‐c]quinazolines

The supramolecular structures of the title compounds, 2‐phenyl‐5‐p‐tolyl‐1,5,6,10b‐tetra­hydro­pyrazolo­[1,5‐c]quinazoline, C₂₃H₂₁N₃, (I), 5‐(4‐bromo­phenyl)‐2‐phenyl‐1,5,6,10b‐tetra­hydro­pyrazolo­[1,5‐c]­quinazoline, C₂₂H₁₈BrN₃, (II), 2‐(4‐chlorophenyl)‐5‐phenyl‐1,5,6,10b‐tetrahydropyrazolo[1,5‐c]quinazoline, C₂₂H₁₈ClN₃, (III), and 5‐(4‐bromo­phenyl)‐2‐(4‐chlorophenyl)‐1,5,6,10b‐tetrahydropyrazolo[1,5‐c]quinazoline, C₂₂H₁₇BrClN₃, (IV), are of two general types. Compounds (I), (II) and (III) form base‐paired dimers via N—H?N hydrogen bonds, where (I) and (II) are isomorphous, while in (IV), there are no conventional hydrogen bonds.     

Unkatalysierte sigmatrope 1,5-Wanderung von Acylgruppen bei der Thermolyse von 5-Acyl-5-methyl-1,3-cyclohexadienen

Uncatalyzed Sigmatropic 1,5-Shift of Acyl Groups in the Thermolysis of 5-Acyl-5-methyl-1,3-cyclohexadienes Four different 5-acyl-5-methyl-1,3-cyclohexadienes 1a–d (R = COOCH₃, COCH₃, COC₆H₅, CHO) have been shown to yield mixtures of 1,3-disubstituted cyclohexadienes 2–7 and 1,3-disubstituted aromatic product 8 upon thermolysis at 150–300° in solution and at 350–500° in the gas phase in a flow system. Two reaction pathways (A and B in Scheme 2) are considered for the rearrangement of the C-Skeleton. For the ester 1a ¹³C-isotopic substitution shows that products arise to 75–86% through a 1,5-sigmatropic shift of the methoxycarbonyl group ( A in Scheme 2) and to 14–25% through a sequence of reaction steps involving a 1,7-H-shift reaction in an acyclic intermediate ( B in Scheme 2). For the more reactive compounds 1b–d isomerization is assumed to follow the 1,5-sigmatropic pathway exclusively ( A in Scheme 2). A kinetic study yields the following sequence for the migration tendency of acyl groups toward sigmatropic 1,5-shift: COOCH₃ < COCH₃ < COC₆H₅ < CHO.     

Synthesis of nitrogen-containing heterocycles. 8. Preparation and ring-opening of spiro[cycloalkane-[1′,2′,4′]triazolo[1′,5′-c]pyrimidine] derivatives

Diaminomethylene- and aminomethylthiomethylenehydrazones [2] of cyclic ketones 1–8 readily reacted with ethoxymethylenemalononitrile to give spiro[cycloalkane-1,2′-[1,2′,4′]triazolo[1,5′-c]pyrimidine-8′-carbonitrile] derivatives 12–19 through the electrocyclic reaction of the initially formed condensation products 26 in moderate to high yields. The spiro[cyclopentanetriazolopyrimidine] derivatives underwent ring-opening at the cycloalkane moiety upon heating in solution to give 2-alkyl-5-substituted-[1,2,4]triazolo[1,5-c]pyrimidine-8′-carbonitriles 20–23 . When an alkyl substituent was introduced into the cyclopentane ring, cleavage of the spiro compounds occurred preferentially at the cyclopentane moiety between the spiro carbon and the more branched one. In contrast, the cyclohexane ring, especially of spiro-5-amino-triazolopyrimidines 17 and 18 strongly resisted to ring-opening under similar conditions, but those of 5-methylthiotriazolopyrimidines 14 gave up to 17 percent of cleavage after prolonged heating in hot ethanol. 2-t-Butyl-5-methylthio-2,3-dihydro[1,2,4]triazolo[1,5-c]pyrimidine-8-carbonitrile 25 [R³ = C(CH₃)₃] was highly susceptible to the cleavage even at room temperature and produced the corresponding 2-unsubstituted triazolopyrimidine 24 with loss of the t-butyl group.     

Komplexkatalyse. X. α-Olefin-Einschub in die Trihapto-allyl-nickel(II)-Gruppierung: Synthese und Eigenschaften von Bis(pentahapto-1,8-nonadien-5-yl-nickel(II)-difluorophosphat)

Complex Catalysis. X. α-Olefin Insertion into the Trihapto-allyl-nickel(II) Group: Synthesis and Properties of Bis(pentahapto-1,8-nonadiene-5-yl-nickel(II)-difluorophosphate) By reaction of (h³-C₃H₅)₂Ni with difluorophosphoric acid in ether under addition of 1,5-hexadiene bis(pentahapto-1,8-nonadiene-5-yl-nickel(II)-difluorophosphate) could be synthesized in good yield, proving thereby preparatively the 1,2-addition of the trihapto-allyl-nickel(II) fragment to the double bond of an α-olefin for the first time.     

Synthesis of 2-(Triazolyl,Oxadiazolyl, and Pyrazolyl) Substituted 1,5-Benzothiazepin-S,S-Dioxide Derivatives of Potential Medicinal Interest

Abstract

The synthetic potential of 2,3,4,5-tetrahydrobenzo[b] [1,5]thiazepine-1,1,4-trione-2-carbohydrazide (5) which resulted from ethyl-4-oxo-2,3,4,5-tetrahydrobenzo[b] [1,5]thiazepine-2-carboxylate (3), on its oxidation with H₂O₂/AcOH followed by treatment with NH₂NH₂.H₂O, was exploited to provide an access to 2-triazolo, 2-oxadiazolo, and 2-pyrazolo substituted derivatives of 1,5-benzothiazepin-4-oxo-1,1-dioxides (6–10), respectively.     

Reactions of closo-1,5-C2B3H5 with Cl2 and with BMe3

Reaction of closo-1,5-C₂B₃H₅ with Cl₂ under reduced temperatures in an inert solvent gives 2-Cl-1,5-C₂B₃H₄. Using a hot/cold reactor a mixture of BMe₃ and 1,5-C₂B₃H₅ is converted to a combination of B-mono-, di-, and tri-methyl derivatives of this smallest closo carborane. In addition, B-mono-, di-, tri-, and tetramethyl derivatives of 2,2$\text{-}\text{?}$C₂B₃H₄C₂B₃H₄, as well as the parent dimer, are produced.     

Methylamination of some 3‐nitro‐1,5‐naphthyridines with liquid methylamine/potassium permanganate

3‐Nitro‐1,5‐naphthyridine and its 2‐substituted derivatives ( 1a‐f ) are dehydro‐methylaminated with a solution of potassium permanganate in liquid methylamine (LMA‐PP) to the corresponding 4‐methylamino‐3‐nitro‐1,5‐naphthyridines ( 3a‐e ). The intermediary 4‐methylamino σ adducts of 2‐R‐3‐nitro‐1,5‐naphthyridines (R ? H, NH₂, Cl, NHCH₃, OC₂H₅, OH) ( 2a‐f ) are detected by ¹H nmr spectroscopy. The observed highly regioselective course of study reactions was confirmed by PM3 quantum chemical calculations of the reaction pathway. The calculations show satisfactory agreement between calculated and observed results. A convenient synthesis of 2‐hydroxy‐ and 4‐methylamino‐3‐nitro‐1,5‐naphthyridine are reported.     

Naphthyridines. Part 3: First example of the polyfunctionally substituted 1,2,4-triazolo[1,5-g][1,6]naphthyridines ring system

Treatment of 1,2,4-triazoles (1) with diethylmalonate in bromobenzene gave 1,2,4-triazolo-[1,5-a]pyridines 2. Chlorination of 2 using POCl₃/DMF (Vilsmeier reagent) led to the isolation of 7-chloro-6-formyl-1,2,4-triazolo[1,5-a]pyridine derivative 4, which reacted with the stabilized ylid 5 to afford 6-ethoxycarbonylvinyl-1,2,4-triazolo[1,5-a]-pyridines 6. Azidation of 6 yielded the corresponding azido compound 7, (Scheme 2). Reduction of 7 with Na₂S₂O₄ gave the corresponding 7-amino compound 8, which cyclized in boiling DMF to give the novel 1,2,4-triazolo[1,5-g][1,6]naphthyridines 9. On the other hand, reacting 7 with one equivalent of PPh₃ (aza-Wittig reaction) in CH₂Cl₂ gave 7-imino-phosphorane derivative 10, and subsequent cyclization in boiling DMF afforded the new 1,2,4-triazolo[1,5-g][1,6]naphthyridine derivative 11 (Scheme 3). However, treatment of 10 with phenyl isothiocyanate in 1,2-dichlorobenzene at reflux temperature gave the new 1,2,4-triazolo[1,5-g][1,6]naphthyridine derivative 14 (Scheme 4). Refluxing 6 with excess of a primary amines 15a,b in absolute. EtOH yielded the corresponding 7-alkyl-amino-1,2,4-triazolo[1,5-a]pyridines 16a,b. These obtained amines 16a,b underwent intramolecular heterocyclization in boiling DMF to give the novel 9-alkyl-1,2,4-triazolo[1,5-g][1,6]-naphthyridines 17a,b, in excellent yields (Scheme 5).     

Synthèse et réactivité des dérivés de la 2,3-dihydro-3-hydroxy-2-phényl-1,5-benzothiazépin-4(5H)-one

New 1,5-benzothiazepinone derivatives have been synthesized. The cycloaddition of benzylazide with 5-propargyl-1,5-benzothiazepinone 7 gave compounds 9 and 10. The 1,5-benzothiazepinone 8 reacts with hydrazine to give 1,5-benzothiazepinone 11, which gave in hot acetic acid compound 12. The reaction of 3-chloro-1,5-benzothiazepinones 13, 14 or 15 with nucleophiles in DMF afforded the 2-benzylidenebenzothiazin-3-ones 16 and 17. The tosylate 18 gave the 1,5-benzothiazepinone 19 by reaction with N₃TMS in the presence of CsF in DMF.     

Organische Phosphorverbindungen 40. Methoden zur Herstellung von Pentamethylen-1,5-bis-(dihydroxyphosphonylmethyl-phosphinsäure) [1]

Alkyl-pentamethylene-1,5-bis-(dialkyloxyphosphonylmethyl-phosphinates) (VII) are formed in high yield by heating alkyl pentamethylene-1,5-diphosphonites, (RO)₂P(CH₂)₅P(OR)₂, with alkyl chloromethylphosphonates, ClCH₂P(O)(OR)₂, at 170° for several hours until evolution of alkyl halides ceases. Hydrolysis to the corresponding acid (VIII) is effected by refluxing with conc. HCl for 40 h. The synthesis and properties of some other 1,5-diphosphorus-substituted pentanes, i.e., H₂P(CH₂)₅PH₂, Cl₂P(CH₂)₅PCl₂, (Et₂N)₂P(CH₂)₅P(NEt₂)₂, (EtO) (HO)P(CH₂)₅P(OH)(OEt), and (HO)₂P(CH₂)₅P(OH)₂, are also reported.     

Reaction of cationic palladium(II) and rhodium(I) complexes with the t-butylperoxy anion: Preparation of t-butylperoxo-palladium(II) and -rhodium(I) complexes

Treatment of the coordinatively unsaturated cationic complexes, [(η-C₃H₅)(Ph₃P)₂Pd^II]PF₆ and [(1,5-COD)₂Rh^I]BF₄, with potassium t-butylperoxide in dichloromethane gives the t-butylperoxometal complexes; (η-C₃H₅)(Ph₃P)(t-BuOO)Pd^II and [(1,5-COD)(t-BuOO)Rh^I](KBF₄), via nucleophilic attack by t-BuOO⁻ on the cationic metal center.     

The preparation of a substituted titanocene-supported polymer and its application in catalytic reactions

A series of polymer-supported RCpCpTiCl₂ (Cp = η⁵  C₅H₅; RCp=η⁵  RC₅H₄) has been prepared and reduced by i-C₃H₇MgBr in situ, then used as catalysts in hydrogenation of styrene, isomerization of 1,5-cyclooctadiene and 1,5-hexadiene, and reduction of carbonyl compounds. In some cases, the introduction of a polymer ligand on the Cp ring restricts the aggregation of active sites and the formation of the inactive dimer of the titanocene species, and results in an increase of activity. Regeneration of polymer-supported titanocene catalysts was performed and the results are presented and briefly discussed.