Synthesis and study of the reactions of 2,5- and 1,2,5-substituted 6-aminoindoles

It has been shown that nitration with a KNO₃ + H₂SO₄ mixture of 2,5-dimethyl- and 5-methyl-2-phenylindoles proceeds strictly selectively with the formation of 6-nitro derivatives, by reduction of which the corresponding aminoindoles were synthesized. It was established that the condensation of the aminoindoles obtained with β-diketones leads initially to enamino ketones, which in the presence of various acidic reagents are not subject to cyclization, i.e. may not be used for the synthesis of the corresponding pyrroloquinolines.     

PMR analysis of nitroquinoline 1-Oxides

Chemical shifts and coupling values obtained from the 100 MHz pmr spectra of 12 nitrosubstituted quinoline 1-oxide derivatives are presented. Spin-spin decoupling, application of the paramagnetic shift reagent tris-(1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedione) europium (III), and calculations of theoretical spectra were used in matching signals to protons in the complex portions of the pmr spectra. Precise spectral parameters were obtained by application of an iterative technique provided by a published computer program. The identification of 4- and 5-nitro substituted quinoline 1-oxides by correlation of pmr spectral parameters with chemical structure is illustrated. The preparation and structural elucidation of two potential carcinogenic compounds, 2,6-dimethyl-4-nitroquinoline 1-oxide and 2,7-dimethyl-4-nitroquinoline 1-oxide are described.     

Synthesis and properties of 3-nitrosocarbazole

The synthesis of 3-nitrosocarbazole (I) by the Fischer-Hepp rearrangement of 9-nitrosocarbazole has been described. The resistance of I to oxidation provides evidence that it cannot be the intermediate in the conversion of 9-nitrosocarbazole to the C-nitro compounds. It has also been shown that I and its derivatives cannot be synthesized by the action nitrosyl chloride on carbazoles. Methylation of I yields 9-methyl-3-nitrosocarbazole, 9,9′-dimethyl-3-azocarbazole and 9,9′-dimethyl-3-azoxycarbazole as the main products. The mechanism of this disproportionation process has been proposed. The spectral data of I are given.     

Nitration in the carbazole series

Nitration of9-tosylcarbazole in acetic anhydride solution gives l-nitro (28%), 2-nitro (19%) and 3-nitro (53%) derivatives. The mixture of the nitro compounds obtained from 9-acetylcarbazole contains 10%, 48% and 42% of the isomers, respectively. Under similar conditions 9-nitrosocarbazole shows a different isomer distribution: 34% of 1-nitro and 66% of 3-nitrocarbazole. Nitration of carbazole is a two step process involving formation and rearrangement of 9-nitrocarbazole. The hypothesis was supported by the results of 1,3,6,8-tetrachlorocarbazole nitration and oxidation of 9-nitrosocarbazole and rearrangement of 9-nitrocarbazole in the nitration conditions.     

Molecular and Crystal Structure of 4,6-Dimethyl-2-(phenylhydrazino)pyrimidine and Its Alkylation and Protonation Products

It was established by X-ray crystallographic analysis that 4,6-dimethyl-2-(phenylhydrazino)pyrimidine forms 2-(2-n-butyl-2-phenylhydrazino)-4,6-dimethylpyrimidine during alkylation with n-butyl bromide and 4,6-dimethyl-2-(phenylhydrazino)-1(H)-pyrimidinium nitrate during protonation with nitric acid. The structure of the molecules and the system of intermolecular hydrogen bonds in the crystals of the compounds are discussed.     

Synthesis of unsaturated derivatives of 2,5-dimethyl-4-phenylpyridine and 3-methyl-2-azafluorene

A substituted butadiene — 1-phenyl-4-(5-methyl-4-phenyl-2-pyridyl)buta-1,3-diene with a trans, trans configuration — was obtained by condensation of 2,5-dimethyl-4-phenylpyridine with cinnamaldehyde. Two 3-methyl-9-cinnamylidene-2-azafluorene isomers are formed as a result of condensation of the same aldehyde with 3-methyl-2-azafluorene. Data from the PMR and IR spectra were used to prove the configuration of the compounds obtained. It was established that the condensation of 3-methyl-2-azafluorene with salicylaldehyde gives 3-methyl-9-(2-hydroxybenzylidene)-2-azafluorene, which has a zwitterionic structure, and 1,2-bis(3-methyl-2-aza-9-fluorenylidene)ethane. Ideas regarding the chemical mechanism of the formation of the latter are presented. The preparation of an unsaturated alcohol — 3-methyl-9-allyl-2-aza-9-fluorenol — is described.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 82–86, January, 1978.     

The synthesis and transformations of 9H-imidazo[1,2-b]pyrazolo[4,3-d]-pyridazine and 9H-pyrazolo[4,3-d]-s-triazolo[4,3-b]pyridazine derivatives

The nucleophilic and electrophilic substitutions of 6-substituted 9,9-dimethyl-9H-imidazo[1,2-b]pyrazolo- [4,3-d]pyridazines 2 , nucleophilic substitutions of 6-substituted 9,9-dimethyl-9H-pyrazolo[4,3-d]-s-triazolo- [4,3-b]pyridazines 7 and some other transformations to give compounds 3 and 8 , respectively, were studied. It was shown that both heterocyclic systems are stable under the conditions employed in these transformations.     

Intermediate products and dyes based on 1-methylnaphth[2, 3-d]imidazole-4, 9-dione

Nitration of 1-methylnaphth[2, 3-d]imidazole-4, 9-dione affords about 30% of -nitro isomers. It is shown that it is possible to synthesize various dyes based on 1-methylnaphth[2, 3-d]imidazole-4, 9-dione. The dyes obtained resemble the corresponding anthraquinones in their color and spectral properties.     

Synthesis and structure of 1,4-diaryl-7,7-dimethyl-1,2,3,4,5,6,7,8-octahydroquinoline-2,5-diones

Condensation of 5-arylidene-2,2-dimefhyl-1,3-dioxane-4,6-diones with 5,5-dimethyl-3-arylamino-2-cyclohexanones yields 1,4-diaryl-7,7-dimethyl-1,2,3,4,5,6,7,8-octahydroquinoline-2,5-diones. The compounds have been characterized from their IR, UV, and PMR spectra. It has been established that the N-phenyl ring, which projects from the plane of the octahydroquinolinedione ring, has a shielding effect on the magnetic field of the protons at the 7- and 8-positions of the ring in the molecules of the compounds synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1227–1232, September, 1993.     

2,5-Dimethyl-4-(p-aminobenzyl)pyridine in the synthesis of substituted quinolines,pyridoindazoles, and isoquinolinoquinolines

2,5-Dimethyl-4-pyridyl(6-quinolyl)methane was obtained from 2,5-dimethyl-4-(p-aminobenzyl)pyridine via the Skraup reaction. The product was nitrated to 2,5-dimethyl-4-pyridyl (5-nitro-6-quinolyl)methane, which was reduced to 2,5-dimethyl-4-pyridyl (5-amino-6-quinolyl)methane. It was established that the diazo compound formed from this amino derivative is converted to 1H,3-(2,5-dimethyl-4-pyridyl)-pyrido [2,3-g]indazole as a result of intramolecular cyclization. 9-Methyliso-quinolino [7,6-f]quinoline was obtained by catalytic dehydrocyclization of 2,5-dimethyl-4-pyridyl (6-quinolyl)methane. 2,5-Dimethyl-4-pyridyl(5-nitro-6-quinolyl)methane has chemochromic properties.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 677–680, May, 1980.     

4′-Bromo(and azido)-10,10-dimethylspiro[9,10-dihydro-10-sila-2-azaanthracene-9,2′-tetrahydrofuran]

Dehydrobromination of 10,10-dimethyl-9-(2,3-dibromoprop-1-y1)-9,10-dihydro-10-sila-2-aza-9-anthrol with butyllithium follows two routes to give the Z- and E-isomers of furan ring-brominated spiro(dihydrosilaazaanthracene-9,2-tetrahydrofuran), and the cis- and trans-isomers of 10,10-dimethyl-9-(3-bromoallyl)-9,10-dihydro-10-sila-2-aza-9-anthrol. Analogous compounds have been obtained bearing an azidogroup in the tetrahydrofuran ring, and a spiran with a dihydrofuran fragment. The pure isomers have been isolated, and their structures established.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 696–700, May, 1989.     

Synthesis and three-dimensional structure of the benzoates and p-nitrobenzoates of the geometrical isomers of substituted 4-hydroxypiperidines

The corresponding stereoisomeric p-nitrobenzoates were obtained by reaction of the geometrical isomers of 1,3-dimethyl-, 1,2,5-trimethyl-, and 1-tert-butyl-3-methyl-4-hydroxypiperidines with p-nitrobenzoyl chloride. The stereoisomers of the corresponding benzoates were also synthesized from the geometrical isomers of 1,3-dimethyl-4-hydroxypiperidines. The primary conformations of the investigated compounds in solution were established by means of their PMR spectra.     

Synthesis and properties of 2-amino-4,6-dimethylnicotinic acid arylamides

It is shown that on boiling 2-amino-4,6-dimethylnicotinic acid arylamides with triethyl orthoformate in acetic anhydride, derivatives of 3-aryl-5,7-dimethyl-4-oxo-3,4-dihydropyrido[2,3-d]pyrimidine are formed. The same compounds are obtained by ternary condensation of ethyl 2-amino-4,6-dimethylnicotinate with triethyl orthoformate and alrylamines. On reaction with urea or ammonium thiocyanate, the ethyl ester or anilides of 2-amino-4,6-dimethylnicothinic acid are converted to 2,4-dioxo- or 4-oxo-2-thio-pyrido[2,3-d]pyrimidines respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1384–1386, October, 1992.     

Peculiarities of the stereochemistry of the disproportionation,ionic, and catalytic hydrogenation of polysubstituted 4H-thiopyrans

The configuration of the thiacyclohexane obtained in the ionic and catalytic hydrogenation of 3,5-dimethyl-2,4,6-triphenyl-4H-thiopyran was established. It is shown that the stereochemistry of these reactions differs for penta- and tetrasubstituted 4H-thiopyrans in that the stereochemistry of the cited processes and the stereochemistry of disproportionation are the same for each of the polysubstituted 4H-thiopyrans.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 910–911, July, 1987.     

Synthesis of three putative kairomones of the beech leaf-mining weevil Orchestes fagi (L.)

The beech leaf-mining weevil, Orchestes fagi (L.), also known as the beech flea weevil, is a common and widespread pest of beech, Fagus sylvatica L., in its native Europe. It now appears to be well established in Nova Scotia, Canada. We report a novel synthesis of 9-geranyl-p-cymene and syntheses of 9-geranyl-α-terpinene and 1,1-dimethyl-3-methylene-2-vinylcyclohexane, making partial use of known methods. All three of these compounds are found in beech leaf volatiles and/or wood and are putative kairomones of the beech leaf-mining weevil.     

Organolithium and organosodium compounds of n-substituted 2-alkylbenzimidazoles

Organolithium and organosodium compounds of 1,2-dimethyl-, 1-methyl-2-ethyl-, 1-methyl-2-propyl-, and 1-phenyl-2-methylbenzimidazole, containing the metal in the alkyl group at position C(₂), were obtained by metallation. It was found that metallation can be complicated by the addition of the metalling reagent at the C=N bond of the heterocycle. It was shown that the obtained organometallic compounds can be used for the synthesis of various derivatives of benzimidazole.The calculation was performed with the standard bond lengths. A planar model was used for the carbanion.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1073–1077, August, 1986.     

α,β-Doppeldeprotonierte Nitroalkane: Super-Enamine? Vorläufige Mitteilung

α,β-Doubly deprotonated nitroalkanes: Super-enamines? At temperatures between ?90° and ?78° both the α and β-proton of 1-aryl-2-nitro-ethanes ( 1 ) are abstracted by n-butyllithium to give the dilithio derivatives of 3 . These turn out to be excellent nucleophiles combining with alkyl halides, aldehydes, ketones, and ω-nitro styrenes at the β-nitro carbon atom to give products of type 2 . It is shown that 2-nitro-propane undergoes the same double deprotonation and can be coupled with benzaldehyde at one of the β-nitro carbon atoms to yield 4 . It is proposed to consider the new reagents as super-enamines 3c .     

Calorimetric determination of activated carbons in aqueous solutions

The interactions among five samples of activated carbons, obtained from different lignocellulosic materials with different degrees of activation of approximately 20% and aqueous solutions of phenol and 4-nitro phenol are studied by means of the determination of immersion enthalpies. It is established that the obtained activated carbons are of a basic character and show values for the pH at the point of zero charge, pH_PZC, that range from 7.4 to 9.7 and, in all cases, higher total basicity contents than the values obtained for total acidity. The immersion heat of the activated carbons in CCl₄ and water is determined obtaining values which are higher for CCl₄ immersion and vary from 31.4 to 48.6 J g⁻¹. The hydrophobic factor, hf, it is calculated from the relation between of the immersion heat of the activated carbons in CCl₄ and the immersion heat in water, the obtained values were 2.98 and 6.75, which are greater than 1 due to the greater values obtained in CCl₄ when compared to the values obtained in water. Immersion enthalpies in phenol solution range from 7.6 to 13.9 J g⁻¹ and for the case of 4-nitro phenol such enthalpies range from 12.7 to 20.5 J g⁻¹; all the 5 samples studied showed a higher value for the heat of immersion in aqueous solutions of 4-nitro phenol.     

辅酶B12模型化合物的研究(Ⅲ)——一类新型烷基钴Schiff碱配合物的合成及Co-C键稳定性

合成与表征了一系列烷基钻Schiff碱配合物RCo(SB)L(R为甲,乙,丙,正丁和异丁基;L为水;SB为双水杨醛缩二甲基丁二胺),它们是一类尚未见报道的新的辅酶B₁₂模型化合物。该配合物的溶液很不稳定,加热或光照促使Co-C键断裂,轴向烷基和平伏面配体对Co-C键稳定性均有影响。经紫外、可见分光光度法及自旋捕集ESR法确定了热分解和光分解反应的产物和超精细分裂常数。     

Azocoupling reaction of 1-benzyl-3,4-dihydroisoquinolines with diazonium salts and the properties of its products

It has been shown that drotaverine base and 1-benzyl-3,3-dimethyl-3,4-dihydroisoquinoline react with diazonium salts to form hydrazones. The position of the K-band in the UV spectra of the compounds obtained depends on the nature of the substituenst in the aromatic ring and the absorption frequency correlates with its Hammett constant. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 246–251, February, 2008.