Reaction 5-(Arylmethylidene)pyrimidine-2,4,6(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>,5<Emphasis Type="Italic">H</Emphasis>)-triones with L-Proline and Aldehydes

Boiling in toluene of 5-(arylmethylidene)pyrimidine-2,4,6(1H,3H,5H)-triones with L-proline and aldehyde led to the formation of previously unknown substituted 1′-arylhexahydro-1H-spiro[pyrimidine-5,2′-pyrrolysine]-2,4,6(1H,3Н,5Н)-triones.     

Synthesis of 6-methyl-8<Emphasis Type="Italic">H</Emphasis>-dibenzo[<Emphasis Type="Italic">a</Emphasis>,<Emphasis Type="Italic">g</Emphasis>]quinolizin-8-imines <Emphasis Type="Italic">via Reissert</Emphasis> compounds

Alkylation of Reissert compounds derived from 3-methylisoquinolines with several 2-cyanobenzylbromides followed by hydrolytic cleavage provided the corresponding 1-benzyl-3-methylisoquinolines. Treatment of the latter with methylmagnesiumiodide caused cyclization to the title compounds rather than formation of 2-acetylbenzylisoquinolines.     

<Emphasis Type="Italic">Z</Emphasis>-and <Emphasis Type="Italic">E</Emphasis>-conformers of <Emphasis Type="Italic">N</Emphasis>-chloroacetylcytisine

N-Chloroacetylcytisine was synthesized by acylation of (–)-cytisine. Stable Z- and E-conformers with respect to rotational isomerism around the N-12–CO bond were found in PMR spectra at room temperature. The point at which PMR resonances of the Z- and E-conformers coalesced upon heating was measured. The transition barrier between the conformers was estimated.     

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.     

Regioselectivity in the reactions of <Emphasis Type="Italic">N</Emphasis>-(polychloroethylidene)-sulfonamides with 1<Emphasis Type="Italic">H</Emphasis>-pyrrole and 1-methyl-1<Emphasis Type="Italic">H</Emphasis>-pyrrole

N-(2,2,2-Trichloroethylidene)arenesulfonamides react with 1H-pyrrole and 1-methyl-1H-pyrrole to give the corresponding N-[2,2,2-trichloro-1-(1H-pyrrol-2-yl)ethyl]arenesulfonamides. The reaction of N-(2,2,2-trichloroethylidene)trifluoromethanesulfonamide with pyrrole leads to a mixture of 2-mono-and 2,5-disubstituted pyrroles, whereas in the reaction with 1-methyl-1H-pyrrole only the 2-substituted compound is formed. N-(2,2-Dichloro-2-phenylethylidene)-4-methylbenzenesulfonamide reacts with 1H-pyrrole to form N-[2,2-dichloro-2-phenyl-1-(1H-pyrrol-2-yl)ethyl]-4-methylbenzenesulfonamide, and its reaction with 1-methyl-1H-pyrrole gives a mixture of 2-and 3-monosubstituted derivatives. The results of quantum-chemical calculations of the initial reactants and products indicate that the process is orbital-controlled. A good agreement is observed between the experimental data and theoretical conclusions concerning the dependence of the reaction regioselectivity on the nature of substituents in the electrophile molecule.     

Regioselective synthesis of polyfluoroalkyl-substituted 7-(1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-1-yl)-6,7-dihydro-1<Emphasis Type="Italic">H</Emphasis>-indazol-4(5<Emphasis Type="Italic">H</Emphasis>)-ones

3-Polyfluoroalkyl-6,6-dimethyl-7-(1H-1,2,3-triazol-1-yl)-6,7-dihydro-1H-indazol-4(5H)-ones were synthesized with high regioselectivity by 1,3-dipolar cycloaddition of terminal alkynes (phenylacetylene, hex- 1-yne, hept-1-yne, and but-3-yn-1-ol) to 7-azido-6,6-dimethyl-3-polyfluoroalkyl-6,7-dihydro-1H-indazol-4(5H)-ones which were prepared by bromination of 6,6-dimethyl-3-polyfluoroalkyl-6,7-dihydro-1H-indazol- 4(5H)-ones with N-bromosuccinimide in anhydrous carbon tetrachloride, followed by treatment of the corresponding 7-bromo derivatives with sodium azide.     

<Emphasis Type="Italic">S</Emphasis>-functional derivatives of 3,4-dihydro-2<Emphasis Type="Italic">H</Emphasis>-1,4-thiasilines

The first cyclic unsaturated S-functional derivatives of 4,4-diphenyl-3,4-dihydro-2H-1,4-thiasiline, S-oxide, S,S-dioxide, and S-sulfonimide, were prepared. Oxidation of the hydrolytically less stable 4,4-dimethyl-3,4-dihydro-2H-1,4-thiasiline leads to the corresponding sulfoxide and sulfone along with the ring opening products, siloxanes containing the sulfoxide or sulfonyl group.     

Three-component heterocyclization of 5-(arylmethylidene)pyrimidine-2,4,6(1<Emphasis Type="Italic">H</Emphasis>,3<Emphasis Type="Italic">H</Emphasis>,5<Emphasis Type="Italic">H</Emphasis>)-triones with aldehydes and amino acids

Previously unknown substituted 4-aryl-2,7,9-triazaspiro[4.5]decane-6,8,10-triones were synthesized in 50–70% yield by heating 5-(arylmethylidene)barbituric acids with N-methyl- or N-phenylglycine and para-formaldehyde or 4-methoxybenzaldehyde in boiling toluene for 14 h.     

The Unusual Transformation of an Aromatic 1<Emphasis Type="Italic">H</Emphasis>-Imidazole into a Non-Aromatic 2<Emphasis Type="Italic">H</Emphasis>-Imidazole

2H-Imidazole derivative 5 has been synthesized and characterized by the X-ray diffraction (XRD) method. The compound crystallizes in the monoclinic space group Cc with cell parameters a = 19.398(1), b = 8.890(1), c = 10.247(1), β = 110.76(1), Z = 4. The molecules are inter-linked through C–H⋅sO and C–H⋅sπ interactions forming infinite chains.     

Tautomerism of azacycles: III. Molecular and crystal structures of 3<Emphasis Type="Italic">H</Emphasis>-and 2-phenyl-1<Emphasis Type="Italic">H</Emphasis>,4<Emphasis Type="Italic">H</Emphasis>-4,5-dihydro-1,2,4-triazole-5-thiones

Compounds capable of tautomerism: sulfanyl-1,2,4-triazole, its C-phenyl derivative, and the crystal hydrate of the latter, were studied by single crystal X-ray diffraction. In the crystals they exist in the form of 3-R-1(H),4(H)-4,5-dihydro-1,2,4-triazole-5-thione with a considerable contribution of the bipolar structure. Published data on the tautomerism of sulfanyl-1,2,4-triazoles and their N-substituted analogs and on the correlation between the spectral characteristics and structures of sulfanyl-1,2,4-triazoles capable of tautomerism are discussed.     

Molecular properties of the copolymers of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride and maleic acid

The hydrodynamic and conformational properties of molecules of poly(N,N-diallyl-N,N-dimethylammonium chloride) and N,N-diallyl-N,N-dimethylammonium chloride-maleic acid copolymers of different compositions in solutions with various ionic-strength and pH values, as well as of the polyelectrolyte complex based on the copolymer with dodecyl sulfate anions in chloroform, are studied. For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in a 1 M NaCl solution, the Kuhn segment length and the hydrodynamic diameter of the chain are estimated as A = 3.9 nm and d = 0.48 nm, respectively. In acidic solutions with pH 3.5, the copolymers demonstrate behavior typical for polyelectrolytes. In an alkaline solution with pH 13, when 1 M NaCl is added to the solution of the copolymer containing 29 mol % maleic acid units, there is an antipolyelectrolyte effect that manifests itself as an increase in the intrinsic viscosity of the copolymer and in the hydrodynamic radius of its molecules. It is found that an increase in the fraction of maleic acid units in the copolymer from 12 to 42 mol % brings about a reduction in the equilibrium rigidity of its macromolecules from 4.1 to 2.2 nm. The equilibrium rigidity of polyelectrolyte-complex molecules is higher than that of initial copolymer molecules owing to steric interactions arising between the aliphatic chains of dodecyl sulfate anions. In an electric field, the molecules of the complex are oriented owing to the induced dipole moment resulting from the displacement of dodecyl sulfate anions along the chain contour.     

Synthesis of 4<Emphasis Type="Italic">H</Emphasis>-imidazole-5-carbaldoxime 3-oxides and 4<Emphasis Type="Italic">H</Emphasis>-imidazole-5-carbonitrile 3-oxides

The condensation of 3-hydroxyamino-3-methylbutan-2-one or 3-ethyl-3-hydroxyamino-pentan-2-one with aldehydes and ammonia afforded a series of new 1-hydroxy-4-methyl-2,5-dihydroimidazoles, whose oxidation gave rise to the corresponding 5-methyl-4H-imidazole 3-oxides. The latter, like 1-hydroxy-4-methyl-2,5-dihydroimidazoles, react with PrⁱONO in the presence of bases to form 4H-imidazole-5-carbaldoxime 3-oxides, which are transformed into 4H-imidazole-5-carbonitrile 3-oxides in the reaction with TsCl in the presence of Et₃N. The by-products produced in different steps of the synthesis were isolated and characterized. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1487–1503, July, 2008.     

Synthesis and study of macroheterocyclic compounds derived from 1<Emphasis Type="Italic">H</Emphasis>-phenalene-1,3(2<Emphasis Type="Italic">H</Emphasis>)-diimine

Symmetrical macroheterocyclic compounds are synthesized by the reaction of 1H-phenalene-1,3(2H)-diimine with m-phenylenediamine, 2,6-diaminopyridine, and 2,5-diamino-1,3,4-thiadiazole. IR and UV spectral data are given.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 8, 2004, pp. 1355–1359.Original Russian Text Copyright © 2004 by Berezina, Vorobev, Vorobeva, Andreikina.This revised version was published online in April 2005 with a corrected cover date.     

7,8,9-trimethyl-1-phenyl-3<Emphasis Type="Italic">H</Emphasis>-pyrrolo[2,1-<Emphasis Type="Italic">d</Emphasis>][1,2,5]triazepin-4(5<Emphasis Type="Italic">H</Emphasis>)-one. Synthesis and reactions

A strategy was developed for the synthesis of 7,8,9-trimethyl-1-phenyl-3H-pyrrolo[2,1-d][1,2,5]-triazepin-4(5H)-one, reactions of its functionalization at the С⁴ atom and aza rings fusion at the С⁴?N³ bond were explored. The formation mechanism of the pyrrolo-1,2,5-triazepinone scaffold was suggested.     

Copolymer of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride with maleic acid as drug carrier

A copolymer of N,N-diallyl-N,N-dimethylammonium chloride with maleic acid of constant composition was prepared under the conditions of radical initiation. The possibility of the functionalization of the copolymer with drugs containing amino groups by polymer-analogous transformations was examined. Conditions were found for preparing conjugates of the copolymer with isoniazid. The structures and the quantitative compositions of the conjugates were determined by ¹³С NMR spectroscopy, and the possibility of preparing conjugates with controlled drug content was demonstrated.     

Reactions of 3-Aroylpyrrolo[1,2-<Emphasis Type="Italic">a</Emphasis>]quinoxaline-1,2,4(5<Emphasis Type="Italic">H</Emphasis>)-triones with 2,3-Dihydrofuran and 3,4-Dihydro-2<Emphasis Type="Italic">H</Emphasis>-pyran

3-Aroylpyrrolo[1,2-a]quinoxaline-1,2,4(5H)-triones reacted with 2,3-dihydrofuran and 3,4-dihydro-2H-pyran to give mixtures of the corresponding hetero-Diels–Alder (furo- and pyrano[3″,2″: 5′,6′]pyrano- [4′,3′: 2,3]pyrrolo[1,2-a]quinoxalines) and Michael adducts (furyl- and pyranylpyrrolo[1,2-a]quinoxalines).     

Analysis of <Emphasis Type="Italic">Escherichia coli</Emphasis> nicotinate mononucleotide adenylyltransferase mutants <Emphasis Type="Italic">in vivo</Emphasis> and <Emphasis Type="Italic">in vitro</Emphasis>

Background  

Adenylation of nicotinate mononucleotide to nicotinate adenine dinucleotide is the penultimate step in NAD⁺ synthesis. In Escherichia coli, the enzyme nicotinate mononucleotide adenylyltransferase is encoded by the nadD gene. We have earlier made an initial characterization in vivo of two mutant enzymes, NadD72 and NadD74. Strains with either mutation have decreased intracellular levels of NAD⁺, especially for one of the alleles, nadD72.