Chloro derivatives of 4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one

The chlorination of 4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one with N-chlorosuccinimide takes place at the methylene group to give mono and diehloro derivatives. In the reaction of the diazepinone with sulfuryl chloride chlorine is incorporated in the 1 or 3 position or in both the 1 and 3 positions, as well as in the para position of the phenyl substituent; in the presence of anhydrous aluminum chloride substitution takes place in the methylene group of the heteroring and in the 8 position of the annelated benzene ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 405–409, March, 1982.     

Bromination of 4-(2-thienyl)thiazoles and 2-(2-thienyl)quinoline

Depending on the substituent, the bromination of 4-(2-thienyl)thiazoles and 2-(2-thienyl)quinoline takes place in the 5 position of the thiophene or thiazole ring. When an amino group is present in the 2 position of the thiazole ring, bromination takes place in the 5 position of the thiazole ring. When excess brominating agent is present, a second bromine atom enters the 5 position of the free ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 35–38, January, 1982.     

Synthesis and reactivity of 4-substituted-2,3-dihydrobenzo-1,4-thiazines

A series of derivatives of 4H-2,3-dihydrobenzo-1,4-thiazine has been prepared. 4-Acetyl-2,3-dihydrobenzo-1,4-thiazine undergoes self-condensation by n-butylmagnesium bromide affording the corresponding 4-aceto-acetyl-2,3-dihydrobenzo-1,4-thiazine, which, is converted to 5H-1,4-thiazino[2,3,4-if]quinolin-5-one. Halogena-tion of the acetyl derivative takes place at the position 2 of the heterocyclic ring and oxidation leads to 1-oxides and 1,1-dioxides.     

Reaction of 2- and 4- alk oxy - 1 - benzopyrylium salts with methylene bases of heterocyclic cations

2-Alkoxy- and 2-alkylthio-1-benzopyrylium salts condense in the 2 position with methylene bases formed from methyl-substituted heterocyclic onium compounds. The 4-methoxy-1-benzopyrylium salt also reacts primarily in the 2 position, during which the benzopyrylium ring is cleaved. In addition, condensation also takes place in the 4 position with splitting out of the methoxy group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 173–177, February, 1977.     

Regioselective bromination of activated aromatic substrates with a ZrBr4/diazene mixture

A regioselective method for the bromination of phenols, ethers and anilines using a ZrBr₄/diazene mixture is described. The reaction takes place under mild reaction conditions and the bromine atom adds first at the para unsubstituted position with respect to the OH, OR or NR₂ group of the activated aromatic substrate. Less reactive compounds such as toluene, phenyl acetate, benzonitrile and trifluoromethylbenzene remain intact under the same conditions.     

Synthesis and properties of analogs of 5(4)-aminoimidazole-4(5)-carboxamide and purines. 14. Acylation of 5(4)-aminoimidazole derivatives

The acylation of 5(4)-aminoimidazole derivatives was studied. It is shown that acylation by means of carboxylic acid anhydrides and chlorides takes place at the amino group, whereas acylation by means of chlorocarbonic acid esters takes place at the nitrogen atoms of the imidazole ring. Methods for the selective introduction of a carbomethoxy group in the 1, 3, and 5 positions of the 5(4)-aminoimidazole-4(5)-carboxamide molecule were developed.See [1] for communication 13.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 247–252, February, 1984.     

Regioselective methylation of 1-benzyl-Δ9, 10-octahydro-4-quinolone

The methylation of 1-benzyl-⁹,¹⁰-octahydro-4-quinolone with methyl iodide in the presence of lithium diethylamide in tetrahydrofuran is a regioselective electrophilic substitution reaction, and, depending on the reaction conditions, takes place in the 3 or 8 position of the quinolone system. Deuteration under the same conditions takes place only in the 3 position.Communication 1 from the series Methylated cis-enamino ketones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 780–784, June, 1982.     

The bromination of 2-amino- and 2-acetylamino-4-(2-furyl)-thiazoles

The bromination of 2-amino-and 2-acetylamino-4-(2-furyl)thiazoles has been studied, and it has been shown that bromination takes place first in the furan ring and then, with an excess of bromine, also in the thiazole ring in position 5.     

Reactions of Polyhalopyridines. 17. Synthesis of 2-, 3-, and 4-Perfluoroalkylthiopolychloropyridines

2-, 3-, and 4-Perfluoroalkylthiopolychloropyridines have been synthesized using perfluoroalkylated thiol and disulfide derivatives of polychloropyridines via the thermal decomposition of Xe(II) bisperfluoroalkylcarboxylates. It was shown that their formation takes place from the starting thiols only through the formation of the disulfides. It was found that 3,4,5,6-tetrachloro-2-trifluoromethylthiopyridine reacts with potassium p-tolylthiolate with retention of the fluorine containing fragment and substitution of the chlorine atom in position 4 of the pyridine ring by the tolythio group.     

Beiträge zur Chemie des Phosphors. 212. Tetraisopropyl-dodecaphosphan(4), P12i-Pr4 – Darstellung,Eigenschaften und Moleküldynamik

Contributions to the Chemistry of Phosphorus. 212. Tetraisopropyldodecaphosphane(4), P₁₂i-Pr₄ – Preparation, Properties, and Molecular Dynamics According to an earlier crystal structure analysis, tetraisopropyldodecaphosphane(4) ( 1 ) exhibits the symmetry C₂, and the substituents are arranged in all-trans position [3]. We have now found by NMR spectroscopic studies that in solution a second configurational isomer of the symmetry C_S ( 1b ) exists in addition to the molecule present in the crystal ( 1a ). The transformation of 1a into 1b , which can only occur through a quasi synchronous inversion at the atoms P³ and P⁴ or P⁹ and P¹⁰, takes place at a noticeable rate already below room temperature.     

A facile synthesis of functionally complex isoxazole derivatives

Metalation of 2(4′-Isoxazolyl)-Δ²-oxazolines takes place initially and selectively on the C-5′-alkyl group. Subsequent metalation also proceeds at this position. Selective deprotection of the oxazoline was accomplished without disturbing the isoxazole ring.     

Acid hydrolysis of N-methyl derivatives of 4-phenyl-5-oxo-4,5-dehydroindeno[1,2-b]pyridine

The splitting of the dihydropyridine ring of N-methyl-substituted 4-phenyl-5-oxo-4,5-dihydroindeno[1,2-b]pyridine in an acid medium takes place at the C-N bond. During the splitting of 1,2-dimethyl-4-phenyl-4,5-dihydroindeno[1,2-b]-pyridine, 4-phenyl-4-(indane-1,3-dion-2-yl)butan-2-one is formed, while in the case of the 3-ethoxycarbonyl derivative of indenopyridine, together with the Michael retroreaction leading to 2-benzylideneindane-1,3-dione, a recyclization of the intermediate product into a derivative of dihydroindeno-2-pyridone takes place.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1363–1366, October, 1986.     

Mass spectra of new substituted 2-amino-4H-pyrans: a retro-Diels-Alder reaction pattern

New substituted 2-amino-3-cyano-4H-pyrans have been studied by electron ionization (EI), chemical ionization (CI) and electrospray ionization (ESI) mass spectrometry. The retro-Diels-Alder reaction (RDA) is the main fragmentation pattern observed in the EI spectra forming an unsaturated ketone as the diene fragment. In contrast, a different RDA reaction takes place yielding an unsaturated amide as diene fragment together with the unsaturated ketone in the CI spectra. The MS/MS spectra obtained using an ESI source reveal that the favoured fragmentation by collision induced dissociation (CID) is the elimination of the substituent at the C4 position with formation of a stable pyrilium cation.     

Über Ligandenumverteilungsreaktionen an ternären Siliciumtetrahalogeniden in Gegenwart von Pyridin

On Ligand-Rearrangement-Reactions at Mixed Silicon Tetrahalides in the Presence of Pyridine The exchange of substituents on mixed silicon tetrahalides completely takes place after few hours in CHCl₃ at 334 K in presence of small quantities of pyridine or pyridinium salts. The exchange equilibria does not deviate much from the values expected from ideal random sorting. Mixed silicon tetrahalides are stable for some days at 298 K in CHCl₃ in presence of pyridine or pyridinium salts respectively, so that by the reaction of binary silicon tetrahalides (SiBr₄, SiI₄) with (pyH)Cl all mixed silicon tetrahalides may be identified side by side. A separation by destillation of the mixtures is impossible because of easy dismutation reactions in presence of pyridine. The influence of pyridine takes place presumable above the formation of addition compounds.     

环双(百草枯对苯撑)-双2-萘甲酸三缩四乙二醇酯二元超分子给受体体系光诱导电子转移研究

本文利用核磁氢谱、吸收光谱和荧光光谱证明了环双(百草枯对苯撑)(CBPQT)与双2-萘甲酸三缩四乙二醇(N-P₄-N)在乙腈溶液中能够形成1:1的二元超分子给受体体系.瞬态吸收光谱的研究表明该超分子体系中光诱导电子转移的速率k_CS>1.0×10⁸s^-1,电子回传的速率k_CR=1.26×10³s^-1,光诱导电子转移所生成电荷分离态的寿命长达794μs.     

A novel approach to 4-benzylisoouinolines

The reaction of quinone methides with 3.4-dihydroisoquinoline or isoquinoline leads to benzylisoquinoline derivatives. NMR and ms investigations as well as chemical degradation prove that benzylation takes place at C-4 of the isoquinoline nucleus. Spectroscopic data are given for all new compounds.     

Bildungsweise und Schwingungsspektren von Antimontetrachlorid-isocyanat [SbCl4NCO]2 und -cyanurat [SbCl4NCO]3

Formation and Vibrational Spectra of Antimony Tetrachloride Isocyanate [SbCl₄NCO]₂ and Cyanurate [SbCl₄NCO]₃ [SbCl₄NCO]₂ was obtained from K[SbCl₅NCO] and SbCl₅ in liquid SO₂. In solution it is only stable at lower temperatures (?20°C); at room temperatures or above irreversible rearrangement to [SbCl₄NCO]₃ takes place. At higher temperatures this also occurs in the solid state, so that both compounds seen to have the same melting point of 208°C. In the molten state decomposition takes place, SbCl₃ being a main product. According to its i. r. and Raman spectrum, [SbCl₄NCO]₂ is an isocyanate with bridging N-atoms. I. r. and Raman spectrum of [SbCl₄NCO]₃ show it to be a derivative of cyanuric acid. Mass spectral data of both compounds are reported.     

Autohetarylation of 4,6-dimethyl-5-nitro-2chloro-3-cyanopyridine — An unexpected transformation in the presence of bases

Under the influence of bases, the 4-6-dimethyl-5-nitro-2-chloro-3-cyanopyridine molecule was found to undergo autohetarylation with the formation of a doubled molecule. Based on RSA data, it was found that such a process takes place exclusively at the methyl group in the 4 position.M. V. Lomonosov Moscow State University, Moscow 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 680–684, May, 1996.     

X-ray structural and spectral study of 1:2 solvate of 2,7-dinitro-4-bromo-10,10-dihydroxyphenanthren-9-one with dimethylformamide

An x-ray structural study showed the total similarity of the behavior of 2,4,7-trinitro- and 2,7-dinitro-4-bromo-9,10-phenanthrenequinones dissolved in aqueous DMF: addition of a molecule of water at one of the two carbonyl groups with formation of the corresponding 10,10-dihydroxyphenanthren-9-ones takes place in both cases in soft conditions. These products of hydration exist as hydrogen-bonded solvates with molecules of the solvent whose crystals are isostructural to each other. The results of the x-ray structural study are in agreement with the data from the IR absorption and electron absorption spectra; their comparison suggests the existence of equilibrium between the starting compounds and the products of hydration, and the equilibrium position is a function of the polarity of the basic solvent.A. N. Nesmeyanov Institute of Organoelemental Compounds, Russian Academy of Sciences, Moscow 117813. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 910–916, April, 1992.     

Direct Umpolung of Glycals and Related 2,3‐Unsaturated N‐Acetylneuraminic Acid Derivatives Using Samarium Diiodide

The umpolung of glycals with samarium diiodide offers a simple route to novel carbohydrate‐derived nucleophilic reagents in a single step using a readily available reductant. The corresponding allyl samarium reagent that arises from the hexose series reacts with ketones at the C3 position with high stereoselectivity; carbon–carbon bond formation takes place only anti to the substituent at the C4 position of the dihydropyran ring. For the sialic acid series, the completely regio‐ and stereoselective coupling process of the samarium reagent occurs at the anomeric carbon atom and provides a new approach to the α‐C‐glycosides of N‐acetyl neuraminic acid.