Reactions of 4-amino-4-azatricyclo[5.2.1.0<Superscript>2,6-<Emphasis Type="Italic">endo</Emphasis></Superscript>]dec-8-ene-3,5-dione with dicarboxylic acid anhydrides

Reactions of 4-amino-4-azatricyclo[5.2.1.0^2,6-endo ]dec-8-ene-3,5-dione (hydrazinolysis product of endic anhydride) with succinic, maleic, cis-cyclohexane-1,2-dicarboxylic, endic, phthalic, and 1,8-naphthalic anhydrides were studied. Procedures for the preparation of the corresponding hydrazido acids and bis-imides were proposed. Their reactions with peroxyformic acid, depending on the substrate nature, led to the formation of both epoxy hydrazido acids and epoxy imides. The unsaturated adducts reacted with p-nitrophenyl azide to give the corresponding triazole derivatives.     

New derivatives of 2-(3,5-Dioxo-4-azatricyclo[5.2.1.0<Superscript>2,6-<Emphasis Type="Italic">endo</Emphasis></Superscript>]dec-8-en-4-yl)acetic acid. Synthesis and reactivity

New urea, carbamates, and carboxamides of the norbornene series were synthesized on the basis of 4-isocyanatomethyl-4-azatricyclo[5.2.1.0^2,6-endo ]dec-8-ene-3,5-dione, and their behavior in reactions with various electrophiles was studied. The structure of the isolated compounds was confirmed by the IR and ¹H NMR spectra.     

Reactivity of 5-<Emphasis Type="Italic">endo</Emphasis>-hydroxy-4-azatricyclo[5.2.1.0<Superscript>2,6</Superscript>]dec-8-en-3-ones and their isomerization initiated by acids and bases

Study of isomerization of 5-endo-hydroxy-4-azatricyclo[5.2.1.0^2,6]dec-8-en-3-ones under the action of Lewis acids (MgBr₂, AlCl₃), CF₃COOH, and NaH showed that the optimum catalyst of the process was trifluoroacetic acid. In reaction of 4-benzyl-5-endo-hydroxy-4-azatricyclo-[5.2.1.0^2,6]dec-8-en-3-one with anhydrous AlCl₃ in benzene was unexpectedly isolated N-benzyl-3-(diphenylmethyl)bicyclo[2.2.1]hept-5-ene-2-carboxamide. A convenient method was developed for the preparation of 5-exo-alkoxy-4-alkyl(aryl)-4-azatricyclo[5.2.1.0^2,6]dec- 8-en-3-ones.     

4<Emphasis Type="Italic">p</Emphasis><Superscript>2</Superscript> resonances in photoionization from 4<Emphasis Type="Italic">s</Emphasis>4<Emphasis Type="Italic">p</Emphasis> levels in neutral zinc

In neutral zinc the 4p ² configuration lies above the 3d ¹⁰4s ionization limit and its levels become perturbers in the continuum. Lines have been identified in the Zn I spectrum for the multiplet, whereas no lines have been found for transitions to 4p ^{2 1} D or ¹ S. In this paper, cross sections for photoionization from 4s4p levels are reported that reveal the positions and widths of the 4p ² resonances. Calculations were performed using the multiconfiguration Hartree-Fock (MCHF) and B-spline R-matrix (BSR) method. Results from Breit–Pauli calculations that ignore the background continua are also presented. Included in the latter are energies for the levels and transition data (transition energies, line strengths, f-values, and A-rates) for all E1 transitions between these levels. Transition energies and the agreement in the length and velocity values, particularly for allowed transitions, indicate the accuracy of the computational model. Line widths are compared with other estimates. Contribution to the Serafin Fraga Memorial Issue.     

Synthesis of 5-(Benzylamino)-<Emphasis Type="Italic">exo</Emphasis>-3-azatricyclo-[5.2.1.0<Superscript>2,6</Superscript>]decan-4-one derivatives

5-(Benzylamino)-exo-3-azatricyclo[5.2.1.0^2,6]decan-4-one derivatives were synthesized in up to 94% yield by condensation of norbornane-fused 3-aminopyrrolidin-2-one with aromatic aldehydes.     

Reactions of ethyl 6,6-dialkyl-8,9-dioxo-5,6,8,9-tetrahydrobenzo[<Emphasis Type="Italic">f</Emphasis>]pyrrolo[2,1-<Emphasis Type="Italic">a</Emphasis>]isoquinoline-10-carboxylates with <Emphasis Type="Italic">N</Emphasis>-nucleophiles

Reaction of enaminoesters, derivatives of 2,2-dialkyl-1,2,3,4-tetrahydrobenzo[f]isoquinoline, with oxalyl chloride leads to the formation of ethyl 6,6-dialkyl-8,9-dioxo-5,6,8,9-tetrahydrobenzo[f]pyrrolo[2,1-a]-isoquinoline-10-carboxylates. At reaction of the latter with ammonia and cyclic amines opening of pyrroledione cycle occurs and the formation of enaminoketoamides, and the reaction with o-phenylenediamine furnishes a fragment of benzimidazole. Hydroxylamine behaves as binucleophile and attacks not only lactam, but also the ester group, affording heterocyclic system of isoxazine-3,4,6-trione.     

Synthesis and structures of benzo[<Emphasis Type="Italic">cd</Emphasis>]furo[2,3-<Emphasis Type="Italic">f</Emphasis>]indol-4(5<Emphasis Type="Italic">H</Emphasis>)-one derivatives

A procedure was developed for the synthesis of derivatives of the new heterocyclic system, benzo[cd]furo[2,3-f]indole, based on the cyclodehydration of 6-acylmethyloxy-1-alkyl-benzo[cd]indol-2(1H)-ones. Either 7- or 8-aryl derivatives of benzo[cd]furo[2,3-f]indol-4(5H)-ones can be prepared depending on the reaction conditions. The molecular and crystal structures of 7- and 8-phenylbenzo[cd]furo[2,3-f]indol-4(5H)-ones were established by X-ray diffraction.     

Synthesis of (2<Emphasis Type="Italic">S</Emphasis>,3<Emphasis Type="Italic">S</Emphasis>,4<Emphasis Type="Italic">S</Emphasis>)-2,3-<Emphasis Type="Italic">O</Emphasis>-isopropylidene-4-(methoxycarbonylmethyl)cyclopentan-1-one

(2S,3S,4S)-2,3-O-Isopropylidene-4-(methoxycarbonylmethyl)cyclopentan-1-one was synthesized starting from D-ribose through methyl (Z)-3-(5-acetyl-2,2-acetoxyacetyl-2,2-dimethyl-1,3-dioxolan-4-yl)prop-2-enoate which was subjected to cyclization in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, followed by decarboxylation.     

Reaction of N-substituted <Emphasis Type="Italic">exo</Emphasis>-2-hydroxy-5-oxo-4-oxatricyclo[4.2.1.0<Superscript>3,7</Superscript>]nonane-<Emphasis Type="Italic">endo</Emphasis>-9-carboxamides with acetic acid

Acylation of N-substituted exo-2-hydroxy-5-oxo-4-oxatricyclo[4.2.1.0^3,7]nonane-endo-9-carboxamides on heating in boiling glacial acetic acid gave the corresponding trans-diacetoxy imides of the norbornane series. The effect of the reaction time on the product composition was studied in the reaction with exo-2-hydroxy-N-(4-methylphenyl)-5-oxo-4-oxatricyclo[4.2.1.0^3,7]nonane-endo-9-carboxamide. The structure of the resulting norbornane-2,3-dicarboximides was confirmed by IR, ¹H NMR, and mass spectra, and the structure of N-(2,5-dimethylphenyl)-exo-2,endo-3-diacetoxybicyclo[2.2.1]heptan-endo-5,endo-6-dicarboximide was additionally proved by X-ray analysis.     

Recyclization of 1,3-dialkyl-6-nitro-1<Emphasis Type="Italic">H</Emphasis>-imidazo[4,5-<Emphasis Type="Italic">b</Emphasis>]pyridine-2,5(3<Emphasis Type="Italic">H</Emphasis>,4<Emphasis Type="Italic">H</Emphasis>)-diones into imidazole derivatives

Treatment of 5-amino-1,3-dialkyl-2,3-dihydro-1H-imidazo[4,5-b]pyridin-2-ones with sodium nitrite in aqueous HCl gave 1,3-dialkyl-1H-imidazo[4,5-b]pyridine-2,5(3H,4H)-diones which were nitrated with potassium nitrate in sulfuric acid to 6-nitro derivatives, and the latter underwent recyclization into 4-amino-1,3-dialkyl-5-(1H-pyrazol-5-yl)-2,3-dihydro-1H-imidazol-2-ones by the action of hydrazine hydrate.     

DFT-calculated structure of protonated tetraphenyl <Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">tert</Emphasis>-butylcalix[4]arene tetraketone

Using DFT calculations, two of the most probable structures (A, B) of the tetraphenyl p-tert-butylcalix[4]arene tetraketone·H₃O⁺ cationic complex species were derived. The hydroxonium ion H₃O⁺, placed in the coordination cavity formed by the calix[4]arene lower-rim groups, is bound by strong hydrogen bonds to the phenoxy oxygen atoms of the calix[4]arene ligand (structures A, B) and also to one carbonyl oxygen (structure B). Correspondence: Emanuel Makrlík, Faculty of Applied Sciences, University of West Bohemia, Pilsen, Czech Republic.     

3-(4-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylaminophenyl)-2-nitro-1-phenylprop-2-en-1-one by <Superscript>13</Superscript>C NMR spectroscopy and X-ray diffraction analysis

X-ray diffraction analysis established that 3-(4-N,N-dimethylaminophenyl)-2-nitro-1-phenylprop-2-en-1-one has E configuration both in crystal and in solution. The benzoyl group deviates from the styrene plane by 89.83°. The elongation of the C=C bond and shortening of its surrounding single bonds points to a high polarization of the molecule, implying a great contribution of the bipolar structure to the ground state.     

Synthesis of (<Emphasis Type="Italic">E</Emphasis>)-<Emphasis Type="Italic">N</Emphasis>-(3-alkoxy-4-acyloxyphenylmethylene)-<Emphasis Type="Italic">N</Emphasis>-(<Emphasis Type="Italic">e</Emphasis>-cyclohexyl)amines

Previously unknown E isomers of azomethines (Schiff bases) were synthesized from vanillal and vanillin esters by their reaction with cyclohexylamine.     

Nickel catalysis for hydrogenation of <Emphasis Type="Italic">p</Emphasis>-dinitrobenzene to <Emphasis Type="Italic">p</Emphasis>-phenylenediamine

The activity of supported nickel catalysts (5–20% Ni) in the hydrogenation of p-dinitrobenzene to p-phenylenediamine was investigated. The catalysts were obtained by ureainduced precipitation. Activated carbon, alumina, titania, and silica gel were evaluated as supports. The most active catalysts, 5%Ni/TiO₂ and 20%Ni/SiO₂, provided 50–54% yields of p-phenylenediamine at complete dinitrobenzene conversion.     

Synthesis of acridinyl- and fluorenylidenehydrazido derivatives of <Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">tert</Emphasis>-Butylcalix[4]arene

p-tert-Butylcalix[4]arenes substituted at the lower rim by acetic acid hydrazide residues reacted with methoxy(ethoxy)acridine and fluoren-9-one derivatives to give a series of calixarenes containing N′-fluorenylidene- and N′-acridinylacetohydrazide residues. It was found that modification of the hydrazide moiety does not affect the conformation of the initial macroring and that it can lead in some cases to unsymmetrically substituted calixarenes.     

Synthesis of Mono- and Tetraalkylamide Derivatives of <Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">tert</Emphasis>-Butylthiacalix[4]arene

Mono- and tetrasubstituted derivatives of p-tert-butylthiacalix[4]arene containing acrylate and acrylamide fragments are synthesized for the first time. The Michael aza-addition of benzylamine to the synthesized acrylamide and acrylate thiacalixarene derivatives is studied.     

Regioselective Reaction of <Emphasis Type="Italic">N</Emphasis><Superscript>1</Superscript>-Benzyl-<Emphasis Type="Italic">N</Emphasis><Superscript>2</Superscript>-(4-nitrophenyl)ethanediamide and Acetylenic Esters

Summary. The regioselective reaction of N¹-benzyl-N²-(4-nitrophenyl)ethanediamide with dialkyl acetylenedicarboxylates or alkyl propiolates in the presence of triphenylphosphine leads to dialkyl 4-benzylamino-1-(4-nitrophenyl)-5-oxo-2,5-dihydro-1H-pyrrole-2,3-dicarboxylates or alkyl 4-benzylamino-1-(4-nitrophenyl)-2-oxo-5-pyrrolidinecarboxylates in good yields.     

Reactions of 2-(2-propynylsulfanyl)-5,6,7,8-tetrahydrobenzo[<Emphasis Type="Italic">b</Emphasis>]thieno[2,3-<Emphasis Type="Italic">d</Emphasis>]pyrimidin-4(<Emphasis Type="Italic">3H</Emphasis>)-one with arylsulfenyl chlorides

2-(2-propynylsulfanyl)-5,6,7,8-tetrahydrobenzo[b]thieno[2,3-d]pyrimidin-4(3H)-one with arylsulfenyl chlorides in chloroform gave products of anti-Markownikoff Ad _E-addition. The use of nitromethane as solvent in the presence of lithium perchlorate additives favored intramolecular electrophilic cyclization into 1-arylsulfanyl-1,2,6,7,8,9-hexahydro-4H-benzo[4,5]thieno[3,2-e][1,3]thiazolo[3,2-a]-pyrimidin-5-one.     

Synthesis of epothilones molecule fragment (15<Emphasis Type="Italic">R</Emphasis>)-C<Superscript><Emphasis Type="Italic">13</Emphasis></Superscript>-C<Superscript><Emphasis Type="Italic">21</Emphasis></Superscript> from D-mannitol

Efficient synthesis of an epothilone molecules fragment (15R)-C¹³-C²¹ was carried out from D-mannitol through its conversion into methyl 2,3-O-cyclohexylidene-D-glycerate followed by the cyclopropanation of the ester group with ethylmagnesium bromide in the presence of titanium(IV) isopropoxide and the transformation of the obtained cyclopropanol into the corresponding 2-substituted allyl bromide. The coupling of the latter catalyzed by copper with 2-methylthiazolyl-4-magnesium bromide, the shift of a double carbon-carbon bond in the product obtained into the position, conjugated with the thiazole ring, and the common transformation of the protected 1,2-diol function afforded the target compound in 15% yield.