Study of Friedel-Crafts acetylation of indolobenzo[b]furans,indolobenzo[b]thiophenes,pyrrolocarbazole, and pyrrolophenothazine dioxide by1H NMR spectroscopy

The reactivity towards Friedel-Crafts acetylation of the new heterocyclic systems indolo[5,6-d]- and indolo[5,4-d]benzo-[d]furans, 3H pyrrolo[2,3-c]carbazole, indolo[7,6-d]-, indolo[4,5-d]- and indolo[5,4-d]benzo-[b]thiophenes and 3H-pyrrolo[2,3-c]phenothiazine-11,11-dioxide have been studied. Under acid conditions these heterocycles behave like indole to give dimerization products, but anomalies were observed in a number of cases. These principles have been established by detailed analysis of the ¹ H NMR spectra of the reaction products. Georgian Technical University, Tbilisi 380075. D. I. Mendeleev Russian Chemical Technological University, Moscow 125047. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1078–1091, August, 1995. Original article submitted June 12, 1995.     

Some physicochemical properties of the structure of 4a-indolyl derivatives of fervenulin and its 3-substituted analogues

The¹H and¹³C NMR and the IR spectra of the antibiotic fervenulin and its 3-substituted analogues and their 4a-indolyl derivatives are considered. Diagnostic spectral characteristics of the compounds mentioned have been revealed. Information on the structure of the 4a-indolyl derivatives of the fervenulins obtained with the aid of NMR and IR spectroscopies has been confirmed and supplemented by an x-ray structural analysis performed for crystals 4a-(indol-3-yl)-6,8-dimethyl-2,4a-5,6,7,8-hexahydropyrimido[5,4-e] [1,2,4]triazine-5,6-dione.S. M. Kirov Urals Polytechnic Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 110–117, January–February, 1991.     

4-Thiazolidinones with cyclic substituents in the 2 position

Cycloalkyspiro-4-thiazolidinones are synthesized by the reaction of several cyclic ketones with 2-mercaptopropionic or thioglycolic acids in the presence of an ammonium salt. The reaction of thioglycolic acid with N-benzylidene derivatives of adamantylalkylamines or hydroxyphenylethylamines leads to the corresponding N-substituted 5-phenyl-4-thiazolodinones. By the condensation of adamantanone thiosemicarbazide, or its hydroxy derivative, with chloroacetic acid, the corresponding substituted hydrazones are obtained.Farmzashchina NPTS, Khimki, Moscow Obl., 141400. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 991–994, July, 1994. Original article submitted May 18, 1994.     

Hydrogenation of complexes of diastereotopicN-benzoyldehydrodipeptides

The replacement of theN-acetyl group by anN-benzoyl group inN-acyldehydrodipeptides results, first, in an increase in the asymmetric induction in their hydrogenation in the case ofN-Bz-Phe-(S)-Glu.N-Bz-(S)-Phe-(S)-Glu is obtained with a diastereomeric excess (de) of 52 %. Second, no poisoning of the Pd-catalyst by sulfur inN-Bz-Phe-(S)-Met occurs, andN-Bz-(R)-Phe(S)-Met is obtained with ade of 26 %. The formation of complexes ofN-Bz-Phe-AA with Ca²⁺ and Mg²⁺ ions does not, as a rule, affect the diastereoselectivity of the hydrogenation. The structure of the dehydrodipeptides has been determined on the basis of¹H NMR spectra, potentiometric titration, and molecular mechanics calculations.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 884–887, May, 1994.This work was carried out with the financial support of the Russian Foundation for Basic Research (Project 93-03-4646).     

Interconversions of isatin-containing condensed tetracyclic systems

A new pathway has been proposed for the synthesis of dioxodihydro-1H-benzo[b]thiophenoindoles from the corresponding isomeric “amino acids” with amino groups at C₍₂₎ and C₍₃₎. This method yields these tetracyclic systems not only as a single isomer but also permits their interconversion. Linear isomers may be obtained from angular tetracyclic systems and, vice versa, the isomer with angular fusion of the pyrrole ring may be obtained from the linear isomer. The classical Sandmeyer reaction was used as a model for such conversions. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 780–786, May, 2006.     

Trends in the NMR chemical shifts of F19 and the NQR spectra of Cl35 and Br79 in halonitroalkanes

F¹⁹ NMR chemical shifts _F are reported for fluoronitroalkanes, which are found to show a nearly linear relation to the NQR shifts for the chlorine and bromine analogs. The spin-spin coupling constant J_F-N also indicates that the Hal-C-N angles vary little in the series Hal_nC(NO₂)_4-n. The empirical relation can be used to predict the properties of new halonitromethanes. The observed trends in _F and _Cl when H is replaced by X (with X=Cl, F, or NO₂) for the halonitromethanes indicate the sequence NO₂, F, Cl as regards shift _F towards weaker fields, but the sequence F, Cl, NO₂ as regards shift _Cl towards higher NQR frequencies. The deviations from a linear relation for mixed halonitromethanes containing electron-donor groups indicate either that the distortion of the tetrahedral angle varies with the halogen or that conjugation effects for F¹⁹ NMR are different from those for Cl³⁵ and Br⁷⁹ NQR.     

Investigation of the structure and complex-formation of isomeric pyrrolophenanthridines and their quaternary salts by1H and13C NMR spectroscopies

It has been shown by NMR spectroscopy that quaternary salts of the isomeric pyrrolophenanthridine series from - self-associates of the stacking structure type in an aqueous medium. The changes in the protonic chemical shifts in DMSO and in water that have been found have enabled the structure of a - self-associate of a salt of the isomer showing the greatest antitumoral activity to be obtained. The order and the values of the self-association constants for the methosulfates of the pyrrolophenanthridines investigated have been calculated from the concentration dependences of the protonic CSs.D. I. Mendeleev Moscow Institute of Chemical Technology. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 407–413, May–June, 1991.     

A new approach to the synthesis of indole-and benzofuran-containing tetracyclic condensed systems

A new method is described for the synthesis of the 1H-benzo[b]furoindole heterocyclic systems from the corresponding isomeric amino acids with amino groups at positions 2 and 3. By this method it is possible to obtain these tetracyclic systems not only in the form of one isomer but also to convert them from one to the other. From the tetracyclic systems with angular structure it is possible to obtain the corresponding linear isomers. On the other hand, from the isomer with the linear structure it is possible to change to the isomer with angular fusion of the pyrrole ring. The classical Fischer reaction served as model for such transformations. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1463–1471, October, 2007.