Acetals of lactams and acid amides. 73. Synthesis and some properties of derivatives of 6-nitro-γ-carboline

We have developed two synthesis routes for 4-amino derivatives of 6-nitro--carbolines: 1) consecutive conversion of 1,2-dimethyl-3-formyl-5-nitroindole to the 3-cyano derivative, condensation of the latter with DMF diethyl acetal, and cyclization of the enamine formed in this case with ammonia and benzylamine; 2) N-oxidation of 9-substituted 6-nitro--carbolines, transformation of N-oxides to the corresponding -carbolin-4-ones, from which the target compounds are obtained through the 4-chloro derivatives.For Communication 72, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 502–505, April, 1992.     

Synthesis of Terpenoids. III. Total Syntheses of α-Bisabololone and α-Trans-Atlantone

Recently, anions of “protected” cyanohydrins have been introduced as useful acyl carbanions equivalents in organic synthesis². Continuing with our interest in the use of these reagents for natural product syntheses³, we wish to report a short total synthesis of the sesquiterpene α-bisabololone 1 ^4,5, whose salient feature is a novel application of “protected” cyanohydrins to the synthesis of β-hydroxy ketones.     

Synthesis based on β-phenylethylamines. IX. Synthesis of sulfides of β-phenylethylamines and of N-benzyltetrahydroisoquinolines

New bimolecular sulfur-containing -phenylethylamines and N-benzyltetrahydroisoquinolines have been synthesized from formyl derivatives of diaryl sulfides. The possibility of using metals as catalysts for obtaining diaryl sulfides in the reaction of ortho-substituted benzaldehydes with SCl₂ has been shown for the first time.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 731–735, September–October, 1995. Original article submitted November 11, 1994.     

Alkaloids of Arundo donax. XIV. Crystal and Molecular Structure of N-Methyl-tetrahydro- β-carboline

An indole alkaloid of the N-methyl-tetrahydro--carboline series was isolated for the first time from Arundo donax, Poaceae. Its structure was solved by X-ray structure analysis.     

Modifications based on coumarins. II. Synthesis ofα-monoglycerides of karatavic and galbanic acids and their phosphates

The synthesis has been performed of -monoglyceride derivatives of coumarins — karatavic and galbanic acids and their modified derivatives — phosphates. The structures of the compounds have been confirmed by IR, UV, PMR, and¹³C and³¹P NMR spectroscopies.A. B. Bekturov Institute of Chemical Sciences, Academy of Sciences of the Republic of Kazakhstan, Almaty Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 217–220, March–April, 1997.     

Acetals of lactams and amides of acids. 72. Investigation of reaction of cyclic β-nitroenamines with p-benzoquinone

The process of condensation of p-benzoquinone with the secondary cyclic enamines 2-(2-nitromethylene)pyrrolidine, -piperidine, and -hexahydroazepine is very much dependent on the size of the saturated ring in these compounds. With increasing ring size, the content of derivatives of 5-hydroxybenzofuran decreases, and the quantity of derivatives of 5-hydroxyindole increases; with the seven-membered enamine, a substituted 6-hydroxyindole is also formed. For enamines of the pyrrolidine and piperidine series, 1,4-bis-2-(2-nitromethylene)pyrrolidono- or piperidinohydroquinones are also recovered.For Communication 71, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 357–362, March, 1992.     

Two-fragment α-adrenolytics. 4. Synthesis of phosphorylated derivatives of 2-aryloxyethylamines and N-phenylpiperazine

The reactions of 3-chloropropylphosphonates, 3-chloropropylthiophosphonates, or 3-chloropropylphosphinates with 2-aryloxyethylamines or N-phenylpiperazine afford the corresponding 3-(2-aryloxyethylamino)propylphosphonates and -phosphinates or 3-(4-phenylpiperazin-1-yl)propylphosphonates and -phosphinates. The compounds obtained exhibit -adrenolytic and hypotensive activities, the latter being found to depend on the substituents at the P atom.     

X-ray structural investigation of gossypol and its derivatives. XXVII. Structure of the condensation product of gossypol and (−)-α-phenyletiiylamine

The structure of the product of condensation of gossypol with (–)--phenylethylamine has been determined. It has been shown that a possible cause of the difficulty in separating racemic gossypol into optically active components is not a racemization of (–)--phenylethylamine on its condensation with gossypol but the high tendency of gossypol and its derivatives to form dimers.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 676–681, September–October, 1995. Original article submitted February 6, 1995.     

Donor-Acceptor Complexes in Copolymerization. XVI. NMR Analyses of Alternating and Random Copolymers of Styrene and α-Methylstyrene with Acrylonitrile and Methacrylonitrile

An NMR investigation was carried out on random and alternating copolymers of acrylonitrile (AN) with a-methylstyrene (MS) and methacrylonitrile (MAN) with α-methylstyrene and styrene (S). The alternating MS-AN copolymer, prepared by complexation with AlEti_1-5Cl_1-5, was found to have a predominantly coisotactic configuration which was attributed to the interaction between the CH₃ and CN groups. The cotacticity of the alternating copolymer was found to be independent of the temperature of polymerization and the amount of AlEt_1-5Cl_1-5 used for complexation. The NMR spectra of random MS-AN copolymers of varying compositions indicated a high value (0.85) for the coisotacticity probability parameter (σ). The equimolar random MS-AN copolymer was also found to have essentially alternating sequences which was attributed to their low reactivity ratios. The equimolar alternating MS-MAN copolymer was found to have a random stereochemical configuration in which the coisotactic placement was slightly preferrred over the cosyndiotactic placement. The NMR spectrum of the equimolar free radical initiated MS-MAN copolymer lacked the fine structure observed in the spectrum of the alternating copolymer which was attributed to the presence of other sequences. The equimolar alternating S-MAN copolymer was found to have a high coisotactic configuration similar to that observed in the MS-AN copolymer. The equimolar free radical initiated S-MAN copolymer had a random sequence distribution.     

Generation and cyclization of α-diazocarbothioimidates. Synthesis and structure of derivatives of 5-mercapto-1,2,3-triazole

The reaction of 5-amino-1,2,3-thiadiazol-4-carbothioamides with methyl iodide basically generates -diazo-S-methylthioimidates and -carbothioimidolates. It is shown that the reactivity of the latter increases when either alkyl or aryl substituents are introduced at the nitrogen atom of the carbothioamide groupTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 979–984, July, 1992.     

Polymorphism of Inclusion Complexes and Unsolvated Hosts. IV. Dimorphism of the Acetone Host–Guest Complex of Dianilinegossypol. Structures of the α- and β-Phase Complexes

Crystal structures of the - and -phase inclusion complexes of dianilinegossypol with acetone obtained at 20° and 30 °C, respectively, have been determined by X-ray structure analysis. Crystal data of the -phase complex are: C₄₂H₄₀O₆N₂2C₃H₆O, orthorhombic, space group Pccn, a = 29.501(9), b = 10.866(2), c = 13.756(3) Å, V = 4409(1) ų, Z = 4, D _x = 1.18 g cm^-3. The structure has been refined to a final R value of 0.117 for 1401 observed reflections. The host–guest ratio for the -phase complex is the same (1 : 2) and the crystals are monoclinic, space group C2/c, a = 28.352(6), b = 11.836(2), c = 13.196(1) Å, = 93.05(1)°, V = 4422(2) Å3, Z = 4, D _x =1.18 g cm^-3. The structure has been refined to a final R value of 0.077 for 1414 observed reflections.In both phases molecules of dianilinegossypol form hydrogen-bondedribbons by O(4)–-HO(3) H-bonds. Phases are determined by the same structural motif. In the -phase complex the cages are in the form of prisms but in the -phase clathrate they undergo a modification by shrinking in two directions and widening in one. Molecules of acetone are hydrogen bonded to the host molecules via aO(1)–-HO(G) bond and are accommodated in cavities for both complexes, i.e. both phases are cryptate-type inclusion complexes.Supplementary data relevant to this publicationhave been deposited with the British Library,No. SUP 82227 (24 pages).     

Total synthesis and properties of prostaglandins. 40. Synthesis ofβ-Oxyaminovinyl bicyclic γ-lactones

Acetylation of oxyiminomethyl bicyclic y-lactones gave the corresponding N-acetyl--oxyaminovinyl derivatives.Latvian Institute of Organic Synthesis, Riga, LV-1006. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 613-615, May, 1995. Original article submitted March 27, 1995.     

Identification and Quantitative Analysis of Nucleosides and Nucleobases in Aqueous Extracts of Fritillaria Cirrhosa D. Don. Using HPLC–DAD and HPLC-ESI-MS

Bulbus Fritillariae cirrhosae is the most widely used medicinal herb for antitussive and apophlegmatic in China and commonly prepared as a water decoction. For clarifying the water-soluble components in Fritillaria cirrhosa D. Don., a simple and sensitive method was developed using high performance liquid chromatography coupled with a photodiode array detector (HPLC-DAD) and an electrospray ionization mass spectrometer (HPLC-ESI/MS) for the quantitative determination and identification of 10 nucleosides and nucleobases. Of the 10 compounds, two (2-deoxyadenosine and hypoxanthine) were identified and determined in F. cirrhosa for the first time. The 10 compounds were separated using a Zorbax SB-Aq column with a gradient elution of methanol and water. All the calibration curves showed good linearity (r² ≥ 0.9991). The recoveries were between 97.7% and 103.5%. The method was validated with respect to precision, repeatability and accuracy, and was successfully applied to the simultaneous determination of the 10 analytes in 24 batches of F. cirrhosa, collected from different parts of China. This report provided a firm basis for clarifying the pharmacological effect and comprehensively evaluating the quality of F. cirrhosa and related preparations.     

Lattice cluster theory of associating polymers. II. Enthalpy and entropy of self-assembly and Flory-Huggins interaction parameter χ for solutions of telechelic molecules

The lattice cluster theory for solutions of telechelic polymer chains, developed in paper I, is applied to determine the enthalpy Δh(p) and entropy Δs(p) of self-assembly of linear telechelics and to evaluate the Flory-Huggins (FH) interaction parameter χ governing the phase behavior of these systems. Particular focus is placed on examining how these interaction variables depend on the composition of the solution, temperature, van der Waals and local "sticky" interaction energies, and the length of the individual telechelic chains. The FH interaction parameter χ is found to exhibit an entropy-enthalpy compensation effect between the "entropic" and "enthalpic" portions as either the composition or mass of the telechelic species is varied, providing unique theoretical insights into this commonly reported, yet, enigmatic phenomenon.     

Synthesis and properties of furan derivatives. 3. Synthesis of 1,2-disubstituted δ2-imidazolines containing furfuryl and tetrahydrofurfuryl groups

The condensation of N-furfuryl- and N-tetrahydrofurfurylethylenediamines with hydrochloride salts of iminoesters of carboxylic acids gives 1,2-disubstituted ²-imidazolines containing furfuryl or tetrahydrofurfuryl groups at N¹.For communication 2, see [1]Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1312–1315, October, 1992.     

A study of the structure and energy of β-diketonates. XVIII. Molecular structure of chromium and cobalt tris-acetylacetonates according to quantum chemical calculations and gas electron diffraction

The molecular structure of chromium and cobalt tris-acetylacetonates is studied by the synchronous electron diffraction and mass spectrometric experiment and quantum chemically. It is found that molecules have the D ₃ symmetry with internuclear distances r _h1(Cr-O) = 1.960(4) Å r _h1(Co-O) = 1.893(4) Å. Quantum chemical calculations by the DFT methods with different basis sets yield a structure well consistent with that found in the experiment. Changes in the structural parameters of chromium and cobalt β-diketonate complexes whose ligands differ in ?CH₃, ?C(CH₃)₃, ?CF₃ substituents are considered.     

Free-Radical Copolymerization of Methyl Methacrylate and α-Methacrylophenone. I. Reactivity Ratios

The free-radical copolymerization of methyl methacrylate and methacrylophenone (MAP) initiated by azobisisobutyroni-trile at 60°C has been studied in ethylbenzene solution and in bulk. The process is characterized by a competitive Diels-Alder condensation of methacrylophenone and by a very low reactivity of methacrylophenone-terminated macroradicals in propagation reactions. The experimental composition data are consistent with a terminal unit model: r_A = 1.77 ± 0.02, r_B = 0.110 ± 0.006. Copolymerization with depropagation of methacrylophenone-terminated growing chains and copolymerization affected by penultimate effects have been tested as optimized possible models to take into account the inability of MAP to undergo homopolymerization.     

Polymorphism of Inclusion Complexes and Unsolvated Hosts. I. Trimorphism of the Host-Guest Complex of Gossypol with Dichloromethane. The Structure of the β-Phase

The formation of host-guest complexes of gossypol at different temperatures has been investigated for the same pressure and concentration. Gossypol forms three different clathrates with dichloromethane within the temperature interval of 22-36 °C. Single crystals of these three modifications (phases) were obtained and their crystallographic parameters measured. The structure of the -phase has been determined previously and the -phase is isostructural to the inclusion complex of gossypol with benzene, while the structure of the -phase has been solved during the present research. Crystals of C30H30O8·CH2Cl2 are triclinic, space group P1, a = 8.604(1), b = 11.858(2), c = 14.405(2) (Å), = 84.60(1), = 89.14(1), = 89.73(1)°, V = 1463(1) Å3, Z = 2, R = 0.089 for 2419 observed reflections.Under ambient conditions gossypol forms unstable tubulates of the -phase; the -phase is a stable cage-type clathrate (cryptate) and the host-guest complex of the -phase is a clathrate of intermediate tubulato-cryptate type.