1H and 13C NMR Spectra of 9H-Pyrimido[4,5-b]indoles

Based on analysis of ¹H and ¹³C NMR spectra of 9H-pyrimido[4,5-b]indole and its 4-phenyl-2-substituted derivatives, we have made assignments for the signals from the ¹H and ¹³C atoms of these compounds.     

Synthesis of partially saturated N-substituted 4H-3,1-benzothiazine-2(1H)-thiones

Summary Acid-catalyzed reaction of 2-arylidenecyclohexanones1 with N-substituted dithiocarbamic acids2 gave open-chain addition products3 and4. Dehydration of3 and4 afforded only one of the three possible isomeric N-substituted 4H-3,1-benzothiazine-2(1H)-thiones5 and6.

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Synthese von partiell gesättigten N-substituierten 4H-3,1-Benzothiazin-2-(1H)-thionen

Zusammenfassung Die säurekatalysierte Reaktion von 2-Arylidencyclohexanonen1 mit N-substituierten Dithiocarbaminsäure2 ergab die offenkettigen Additionsprodukte3 und4. Die Dehydratation von3 und4 führte ausschließlich zu einem der drei möglichen N-substituierten 4H-3,1-Benzothiazin-2(1H)-thion-Isomeren5 und6.

     

Correlation NMR spectroscopy of 1,1-dichloro-2,3,4,5-tetraphenyl-1-germacyclopenta-2,4-diene

Assignment of all of the signals in the¹H and¹³C NMR spectra of 1,1-dichloro-2,3,4,5-tetraphenyl-l-germacyclopenta-2,4-diene has been carried out using two-dimensional NMR spectroscopy. Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 3, pp. 623–625, March, 1997.     

Synthesis and structure of tricyclic furanosesquiterpenoids related to pallescensin A

Electrophilic cyclization of (cyclo)farnesanes containing anexo-methylene group in the a-isoprenoid unit smoothly gives regio- and stereoisomeric octalins subsequently transformed to tricyclic furanosesquiterpenoids related to metabolites of some marine organisms.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 156–163, January, 1994.The authors are grateful to the representative of the Bruker company in Moscow, Uve Eichhof, who allowed us to use an AMX-400 spectrometer.     

Stereochemicai study of 7-aryl-1,7,8,8a-tetrahydro-3(2H)indolizinones by1H and13C NMR

Stereochemistry of 7-aryl-1,7,8,8a-tetrahydro-3(2H)-indolizinones was studied by¹H and¹³C NMR. Complete assignment of¹H NMR signals and analysis of¹H-¹H coupling constants were performed using the iterative PANIC program. Values of³ J _6,7,³ J _7,8endo, and⁴ J _5,7 allow one to unambiguously identify the correspondingexo- andendo-stereoisomers. For stereoisomers with exo-orientation of H(7), complete assignment of¹³C NMR signals was performed on the basis of analysis of the¹³C-¹H coupling constants using two dimensional heteronuclear shift-correlating spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 591–593, March, 1996.     

Structure of 2-Amino-4-phenyl-9H-pyrimido[4,5-b]indole and Its Nitrate in Crystal and Solution

The crystal structures of 2-amino-4-phenyl-9H-pyrimido[4,5-b]indole and its nitrate were determined by XRD analysis. ¹³C NMR, XRD, and quantum-chemical data indicate that the acid proton is predominantly localized at the N(3) atom of the pyrimidine ring in both isolated nitrate molecules and in molecules in crystal and solution.     

Crystal structure and synthesis of benzimidazole substituted acrylonitriles and benzimidazo[1, 2-a]quinolines

The benzimidazole compounds and benzoannulated cyclic benzimidazole analogues, such as benzimidazo[1,2-a]quinolines, are a part of our wider investigation on biologically active compounds, potential antitumor drugs. Here, we present the synthesis of two compounds, [2-(1H-benzimidazol-2-yl)-3-(4-bromophenyl)-acrylonitrile, 5] and [2-bromo-benzimidazo[1,2-a]quinoline-6-carbonitrile, 7] and their crystal structures revealed by X-ray single crystal diffractometry. We also report the molecular and crystal structures of two additional compounds [2-(1H-benzimidazol-2-yl)-3-(4-cyanophenyl)-acrylonitrile, 4] and [benzimidazo[1,2-a]quinoline-2,6-dicarbonitrile, 6], whose synthesis and spectroscopic characterization have been published earlier by us too (Hranjec and Karminski-Zamola, Molecules 12:1817, 2007). The compounds 4 and 5 crystallize as monohydrates. The dihedral angles calculated between phenyl and benzimidazole ring reflect not significant deviation from molecular planarity in the crystalline state for 4 and 5, while benzoannulated cyclic benzimidazole derivatives 6 and 7 are essentially planar. The crystal structures of 4 and 5 are characterized by O–H···N and N–H···O hydrogen bonds between water molecule of crystallization and imidazole NH group as well as CN group, while in 6 and 7 only weak C–H···N intermolecular hydrogen bonds exist. Although, crystal packings are analogous in 4 and 5, the molecular conformations differ slightly. In 6 there is one C–H···N hydrogen bond that do not exist in 7.     

Flavonoid glycosides fromThalictrum squarrosum St. ex Willd. andThalictrum minus L.

Two flavonoid allose diglycosides were found in the terrestrial part ofThalictrum squarrosum St. ex Willd. andT. minus L. (Ranunculaceae). 7,4′-Di-O-β-allopyranosylapigenin was isolated fromT. minus. InT. squarrosum, its monoacetate was also found and characterized as 7-O-(6-O-acetyl-β-allopyranosyl)-4′-O-(β-allopyranosyl)apigenin. The sites of attachment of the carbohydrate residues were determined by HMBC; the location of the acetate group was identified by ROESY. Both substances were isolated from these plants for the first time. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 392–394, February, 1999.     

Synthesis and transformations of 3-(1H-pyrrol-1-yl)thieno[2,3-b]pyridines

Reactions of 2,5-dimethoxytetrahydrofuran with 3-aminothieno[2,3-b]pyridines afford a number of substituted 3-(1H-pyrrol-1-yl)thieno[2,3-b]pyridines. The possibility of the reaction and the yield of the product are determined by the character of a substituent in position 2 of thieno[2,3-b]pyridine. The Curtius rearrangement of 2-acylazido-3(1H-pyrrol-1-yl)thieno[2,3-b]pyridines yields 4,5-dihydropyrido[3",2":4,5]thieno[2,3-e]pyrrolo[1,2-a]pyrazin-4-ones. The molecular and crystal structures of ethyl 4-methoxymethyl-6-methyl-3-(1H-pyrrol-1-yl)thieno[2,3-b]pyridine-2-carboxylate were determined by X-ray diffraction analysis.     

13C and1H NMR spectra of substituted dihydropyrroles prepared by the reaction of 2-aminooxazoles and maleimide

Substituted dihydropyrroles were characterized by¹³C and¹H NMR spectra. The spectral patterns of these compounds and reversible hydrogen—deuterium exchange are discussed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 697–700, April, 2000.     

Cerebrosides fromfomitopsis pinicola (Sw. Ex Fr.) Karst.

Summary A cerebroside fraction was obtained from the fruit bodies offomitopsis pinicola using column chromatography and then separated into six compounds by reversed-phase HPLC. The sugar component of all cerebrosides wasD-glucose. The major fatty acids were 2-hydroxyfatty acids (C₁₄–C₁₈), the long chain base was identified as 9-methyl-C₁₈-4,8-sphingadienine which is widely distributed in fungi and reported to be essential for the fruit-inducing activity of fungi. Based on degradation studies, fast atom bombardment mass spectrometry, and different¹H and¹³C NMR investigations, the structure of the main cerebroside (1) was determined to be (4E,8E,2S,3R,2R)-N-2-hydroxypalmityl-1-O--D-glucopyranosyl-9-methyl-4,8-sphingadienine.

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Cerebroside ausFomitopsis pinicola (Sw. Ex Fr.) Karst.

Zusammenfassung Aus den Fruchtkörpern vonfomitopsis pinicola wurde ein Cerebrosidgemisch erhalten und durch Säulenchromatographie und HPLC in sechs Verbindungen aufgetrennt. Der Zuckerbaustein aller Cerebroside warD-Glucose. Die Fettsäurekomponenten waren 2-Hydroxyfettsäuren mit einer Kettenlänge zwische C₁₄ und C₁₈. Der Basenteil konnte als 9-Methyl-C₁₈-4,8-sphingadienin identifiziert werden. Diese Verbindung ist in Pilzen weit verbreitet und für die Fruchtbildung verantwortlich. Aus Abbaustudien, FAB-MS und verschiedenen¹H- und¹³C-NMR-Messungen wurde die Struktur des Hauptcerebrosids (1) als (4E,8E,2S,3R,2R)-N-2-hydroxypalmityl-1-O--D-glucopyranosyl-9-methyl-4,8-sphingadienin ermittelt.

     

New flavonoid oligoside fromAconitum barbatum Pers.

A new flavonoid oligoside,viz. 3-O-[3,4-)di-O-acetyl-β-xylopyranosyl)-α-rhamnopyranosyl]-7-o-(α-rhamnopyranosyl)kaempferol, was isolated from the above-ground part of the plantAconitum barbatum Pers. The product was identified by spectral methods. Published inIzvestiyu Akademii Nauk. Seriya Khimicheskaya. No. 11, pp. 1935–1937, November, 2000.     

NMR studies of 4(3H)-quinazolinones and 4(3H)-quinazolinethiones

Summary Unambiguous¹H and¹³C NMR assignments for 4(3H)-quinazolinones1–6 and their corresponding 4-thiones7–12 have been made. This resulted in the revision of the previous assignments for the two benzenoid carbons (C-5 and C-8) of quinazolinones1,2,4, and5. Thionation of the nucleophilic amides1–6 has been found to cause a distinct change in the¹³C chemical shift of particularly C-4, but also of those of C-4a, C-5, and C-8a. One-bond and several long range heteronuclear coupling constants for the compounds have also been measured.

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Kernresonanzspektroskopie von 4(3H)-Chinazolinonen und 4(3H)-Chinazolinthionen

Zusammenfassung Die¹H- und¹³C-NMR-Spektren der 4(3H)-Chinazolinone1–6 und ihrer entsprechenden 4-Thione7–12 wurden zugeordnet. Dabei zeigte sich, daß eine frühere Zuordnung der beiden benzoiden Kohlenstoffe (C-5 und C-8) der Chinazolinone1,2,4 und5 falsch war. Ersatz des Sauerstoffs durch Schwefel in den nukleophilen Amiden1–6 führt insbesondere für C-4, aber auch für C-4a, C-5 und C-8a zu einer deutlichen Änderung der chemischen Verschiebung. Heteronukleare Kopplungskonstanten über eine und über mehrere Bindungen wurden bestimmt.

     

Generation and reactions of diazo-3,3-dideuterio-2-methylidenecyclopropane and isomerization of 3",3"-dideuterio-2"-methylidenespiro[4,5-dihydropyrazole-5,1"-cyclopropanes] into isopropenylpyrazoles

N-(1,3,3-Trideuterio-2-methylidenecyclopropyl)-N-nitrosourea was synthesized and its decomposition on treatment with K₂CO₃ in the presence of acrylonitrile and ethyl acrylate or on treatment with MeONa in the absence of unsaturated substrates was studied. The rate of decomposition of the nitrosourea is much lower than that of the nondeuterated analog. The use of acrylates for trapping the intermediate 3,3-dideuterio-1-diazo-2-methylidenecyclopropane results in the corresponding 2"-methylidenespiro[4,5-dihydropyrazole-5,1"-cyclopropanes] containing two deuterium atoms in the cyclopropane fragment. The resulting dihydropyrazoles are isomerized almost entirely over a period of 1—3 days to give a mixture (1 : 1) of isopropenylpyrazoles in which both deuterium atoms occur either in the methyl or in the methylidene groups of the isopropenyl substituent. A possible mechanism of this transformation is considered.     

An expeditious synthesis for γ-carboline analogue 4-aryl-1,3-thiazino[6,5-b]indole derivatives via the trifluoromethanesulfonic acid-promoted isomerization of 3-amidomethylthioindole intermediates to 2-indolyl sulfides

A highly efficient trifluoromethanesulfonic acid-mediated rearrangement of the benzoylaminomethylthio group of 3-benzoylaminomethylthioindoles (7a-e) to position 2 of the indole ring was developed. Thus, 2-benzoylaminomethylthioindoles (9a-e) were obtained in good yields and were involved as key intermediates in the synthesis of the new γ-carboline analogue ring system: 2,9-dihydro-4-aryl-1,3-thiazino[6,5-b]indole derivatives (11a-e). The target thiazinoindoles (11a-e) were prepared via 2-thiobenzoylaminomethylindoles (10a-e) in modified Bischler-Napieralski reactions.     

(1)H and (13)C NMR spectral data for a tricyclic derivative of a Diels-Alder adduct

A complete NMR analysis with full assignment for (1)H and (13)C NMR spectral data for 5-(acetyloxy)-3-hydroxy-9,10-dimethoxy-6-oxo-11-oxatricyclo[6.2.1.0(2,7)]undec-2-yl acetate is described. This compound was prepared by rapid hydrogenation of the unstable Diels-Alder adduct obtained from the reaction between 3,4-dimethoxyfuran and 2,5-diacetoxy-1,4-benzoquinone. Full homonuclear hydrogen coupling constants measurements and molecular mechanics calculations were performed for the determination of the relative stereochemistry.     

13C and1H NMR study of 3-R-substitutedtrans-2-oxadecalins and 1-R-substitutedcis- andtrans-2-oxahydrindans

Previously synthesized 3-substitutedcis- andtrans-2-oxadecalins and 1-substitutedcis- andtrans-2-oxahydrindans were studied by ¹³ C and ¹ H NMR. The structure and configuration of these compounds were established.A. V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 117912 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 861–865, April, 1992.     

Study of allylic rearrangement in (μ-H)Os3(μ-O=CNRCH2CH=CH2)(CO)10 (R=H or CH3) clusters

The migration of the double bond in the allylcarboxamide ligands of (μ-H)Os₃(μ-O=CN RCH₂CH=CH₂) (CO)₁₀ (R=H (1) or CH₃ (2)), (μ-D)Os₃(μ-O=CNDCH₂CH=CH₂) (CO)₁₀, and (μ-H)Os₃(μ-O=CNHCD₂CH=CH₂)(CO)₁₀ clusters was studied by¹H,²H, and¹³C NMR spectroscopy. Neither μ-D nor ND groups in the deuterated complexes are directly involved in prototropic processes of allylic rearrangement. Initially, the deuterium atom of the CD₂ group migrates to the ψ-carbon atom of the allyl fragment to form the −CD=CH-CH₂D propenyl moiety, in which the deuterium and hydrogen atoms are gradually redistributed between the ψ-and β-carbon atoms. The triosmium cluster complexes containing the bridging carboxamide ligands O=CNRR' catalyze the allylic rearrangement ofN-allylacetamide. Based on the data obtained, the probable scheme of the allylic rearrangements in clusters1 and2 was proposed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2182–2186, November, 1999.     

New polyhydroxysteroids and steroid glycosides from the far east starfishCeramaster patagonicus

Two new polyhydroxysteroids and five new glycosides were isolated from the starfishCeramaster patagonicus and their structures were elucidated: 5α-cholestane-3β,6α,15β,16β,26-pentol, (22E)-5α-cholest-22-ene-3β,6α,8,15α,24-pentol, (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β,4β, 6α,8,15β,16β,28-heptol (ceramasteroside C₁), (22E)-28-O-[O-(2,4-di-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β, 6α,8,15β,16β,28-hexol (ceramasteroside C₂), (22E)-28-O-[O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β,6α,8,15β,16β 28-hexol (eramasteroside C₃), (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-methyl-5α-cholest-22-ene-3β,4β,6α,8, 15β, 26-hexol (ceramasteroside C₄), and (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-xylopyranosyl]-5α-cholest-22-ene-3β,6α,8,15β,24-pentol (ceramasteroside C₅)). Three known polyhydroxysteroids (24-methylene-5α-cholestane-3β,6α,8,15β,16β,26-hexol, 5α-cholestane-3β,6α,8,15β,16β,26-hexol, and 5α-cholestane-3β,6β,15α,16β,26-pentol) were also isolated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 190–195, January, 1997.