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1.
The results of X-ray crystallographic investigations of compounds containing a 2,2-bithienyl fragment are summarized and analyzed. The structural characteristics of unsubstituted bithiophene, 5-monosubstituted, 5,5-, 3,3-, 4,4-, and 3,4-disubstituted, and more highly substituted bithiophenes and also the structure of -conjugated oligothiophene derivatives are considered.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–760, June, 2000.  相似文献   

2.
A novel fluorimetric method based on use of a hydrophobic cationic cyanine dye has been developed for determination of the anionic surfactant sodium dodecylbenzenesulfonate (DBS). The method is based on the enhancement effect of DBS on the fluorescence of the hydrophobic cyanine dye 2-[-4-chloro-7-(1-ethyl-3,3-dimethylindolin-2-ylidene)-3,5-(propane-1,3-diyl)-1,3,5-heptatrien-1-yl]-1-ethyl-3,3-dimethyl-3H-indolium iodide. Under the optimum conditions the extent of fluorescence enhancement is proportional to the concentration of DBS in the range 0.05–5.0 mg L–1; the detection limit is 0.014mg L–1. The relative standard deviation for 0.35 mg L–1 DBS was 1.1% (n=10). The proposed method, which avoided use of toxic solvents and tedious solvent-extraction, and was applied to the determination of DBS in natural water with recoveries between 99.9 and 107%. Preliminary research shows that the fluorescence enhancement is due to the formation of a dye aggregate facilitated by DBS.  相似文献   

3.
Zusammenfassung Myricetin (3,3,4,5,5,7-Hexahydroxyflavon) wird aus Pflanzenextrakten chromatographisch abgetrennt, mit Methanol eluiert. Das gelbgrüne Fluoreszenzlicht seines Aluminiumchelats wird in Gegenwart von Essigsäure und Ammoniumacetat gemessen. 10–4% Myricetin lassen sich mit einem relativen Fehler von ±4% bestimmen.
Spectrophotometric and fluorometric determination of myricetin (3,3,4,5,5,7 -hexahydroxyflavone)
Summary Myricetin (3,3,4,5,5,7-hexahydroxyflavone) is separated chromatographically from plant extracts and eluted with methanol. The yellow-green fluorescent light of its aluminium chelate is measured in the presence of acetic acid and ammonium acetate. 10–4% Myricetin can be determined with a relative error of ±4%.
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4.
The first representative of a 14-membered macroheterocyclic system — dibenzodipyrazolo-5,12-dihydro[1,2.5,8,9,12]hexaazatetradecyne — was obtained by template cyclization of 5,5-dichloro-3,3-dimethyl-1.1-diphenyl-4.4-azopyrazole with 2.2-diaminoazobenzene in aprotic solvents in the presence of nickel(II) acetate and potassium carbonate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 968–971, July, 1976.  相似文献   

5.
Zusammenfassung Es wird über die Reaktion verschieden methylsubstituierter 4-Hydroxychalkone mittels Chinonimidchlorid berichtet und gezeigt, daß die Ausbeute an 2,6-Dimethylphenol-indophenol bei der Spaltung von 4,4-Dihydroxy-3,5,3-trimethylchalkon (VII) am RingB dreimal so groß ist als beim 4,4-Dihydroxy-3,3,5-trimethylchalkon (III) am RingA.
The reaction between several methyl-4-hydroxy-chalkones and p-benzoquinone-monochloroimine has been studied. It has been shown that the yield of 2.6-dimethylphenol-indophenol from the cleavage of 4.4-dihydroxy-3.5.3-trimethyl-chalkon (VII) at ringB is three times the yield resulting from the cleavage of 4.4-dihydroxy-3.3.5-trimethylchalkon (III) at ringA.


Herrn Prof. Dr.H. Bretschneider zum 60. Geburtstag gewidmet.  相似文献   

6.
Summary 1. In a study of the kinetics of the alkaline hydrolysis of flavone glycosides it has been found that derivatives of 3,3,4,5,7-pentahydroxyflavone hydrolyze faster than derivatives of 3,4,5,7-tetrahydroxyflavone and of 3,4,5,7-tetrahydroxy-3-methoxyflavone.2. In the hydrolysis of diglycosides of 3,3,4,5,7-pentahydroxyflavones the maximum amount of intermediate product is formed after 2 min (3,4,5,7-tetrahydroxyflavone glycoside), and in the case of 3,4,5,7-tetrahydroxy-3-methoxyflavone glycosides after 120–150 min.I. V. Kutateladze Institute of Pharmacochemistry, Academy of Sciences of the Georgian SSR, Tbilisi. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 646–649, September–October, 1977.  相似文献   

7.
The reaction of 3-epoxypropionyl-2-pyrazolines and 3(5)-epoxypropionylpyrazoles with hydrazine hydrate leads to 4,5,4,5-tetrahydro- and -4,5-dihydro-3,3-di-pyrazolyls, on the basis of which 4,5-dihydro-3,3-dipyrazolyls and 3,3-dipyrazolyls were subsequently obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 226–229, February, 1984.  相似文献   

8.
A convenient method has been developed for the synthesis of 5-methyl-2-desoxyuridines. Chlorination of 5-O-benzoyl-5-methyluridines with a mixture of Ph3P and CCl4 in DMF affords the 2-desoxy-2-chloro-derivatives, which are then reduced with tributyltin hydride. The crystalline 5-O-benzoyl-5-methyl-2-desoxyuridines were obtained in overall yields of 40–60%. In a similar way, 5-O-benzoyluridine has given 5-O-benzoyl-2-desoxyuridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 246–248, February, 1989.  相似文献   

9.
Sulfolanethiols, which were oxidized to 3,3-disulfolanyl disulfide and 3,3-bis(4-hydroxysulfolanyl) disulfide, were obtained by reaction of 3-sulfolene and 4-hydroxy-2-sulfolene with sodium hydrosulfide. Previously unknown cleavage of the sulfolanyl sulfides at the C-S bond of the sulfolane ring was observed during their oxidative chlorination and alkaline hydrolysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 188–191, February, 1975.  相似文献   

10.
Trans-N,N-dialkyl-N,N-dibenzoyl-1,2-diamino-1-chloroethylenes — the first representatives of a new chemical class — and N,N-dialkyl-N,N-dibenzoyl-1,2-diaminoethylenes were obtained by benzoylation of N,N-dialkyl-1,4-diaza-1,3-butadienes. On increase in pressure to 10,000 atm, the yields of the N,N-dibenzoylated 1,2-diamino-1-chloroethylenes increase, and those of the N,N-dibenzoylated 1,2-diaminoethylenes decrease.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2038–2041, September, 1989.  相似文献   

11.
By the condensation of -halogenomethyl derivatives of pyrroles with -unsubstituted pyrroles the synthesis of the following unsymmetrical dipyrrolylmethanes has been effected: 5-benzyloxycarbonyl-5-ethoxycarbonyl-3, 3-di(-methoxycarbonylethyl)-4,4-dimethyl-2,2-dipyrrolylmethane (IIIa), 5-benzyloxycarbonyl-5-ethoxycarbonyl-3-(-methoxycarbonylethyl)-4, 4-diniethyl-3-n-propyl-2,2-dipyrrolylmethane(IIIb), 3-acetyl-5-benzyloxycarbonyl-4-ethyl-5-methoxycarbonyl-3, 4-dimethyl-2,2-dipyrrolylmethane (IIIc), and 3-bromo-5-benzyloxycarbonyl-4-ethyl-5-methoxycarbonyl-3, 4-dimethyl-2,2-dipyrrolylmethane (IIId). Hydrogenation of the unsymmetrical dipyrrolylmethanes IIIa, b, c, and d has given the corresponding monocarboxylic acids IVa, b, c, and d. The formylation of the dipyrrolylmethanemonocarboxylic acid IVa has given 5-ethoxycarbonyl-5-formyl-3,3-di(-methoxycarbonylethyl)-4, 4-dimethyl-2,2-dipyrrolylmethane (V).For communication II, see [1].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1045–1047, August, 1970.  相似文献   

12.
3,4,3,4-Tetramethyldiphenyl ether readily forms 2,2-dihalo derivatives on bromination and iodination. Heating 2,2-diiodo-4,5,4,5-tetramethyldiphenyl ether with copper powder or oxidation, of 2,2-dilithio-4,5,4,5-tetramethyldiphenyl ether gives 2,3,7,8-tetramethyldibenzofuran, the structure of which was proved by alternative synthesis from 2,2-dinitroand 2,2-diamino-4,5,4,5-tetramethyldiphenyls.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1597–1599, December, 1972.  相似文献   

13.
Conclusions 1. Xanthalin has been shown to have the structure of 2, 2-dimethyl-3, 4,-diangeloyloxy-3, 4-dihydropyrano-5, 6:6, 7-coumarin on the basis of the preparation of a number of derivatives and cleavage products.2. The following products of the alkaline hydrolysis of xanthalin have been isolated and characterized for the first time: (±)-3, 4-dihydroxy-3, 4-dihydroxanthyletin (isokhellactone), C14H14O5, with mp 213–215° C and (–)-trans-3-hydroxy-4-methoxy-3, 4-dihydroxanthyletin (isomethylkhellactone, C15H16O5, with mp 136.5–138° C and [] D 20 –47.7 (ethanol).Khimiya Prirodnykh Soedinenii, Vol. 6, No. 1, pp. 14–19, 1970  相似文献   

14.
It was established that the reaction of hexabromo-2,2-dithienyl with magnesium in the presence of ethyl bromide gives an organodimagnesium derivative, which reacts with oxalic acid esters to give 3,3,4,4-tetrabromo-5,5-dithienyl-diglyoxalic acid esters. Reduction of the latter with ethylmagnesium bromide leads to 3,3,4,4-tetrabromo-5,5-dithienyl-2,2-diglycolic acid esters.See [1] for Communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 468–470, April, 1981.  相似文献   

15.
The reactions of 1-pyrazoline-3-spiro-4-(1,3-dioxolan-5-one) were studied; this compound is the product of the 1,3-dipolar addition of diazomethane to 5-methylene-1,3-dioxolan-4-one. Depending on the conditions, thermolysis of the spiro compounds proceeds either with destruction of the pyrazoline ring, or with cleavage of the dioxolane ring, followed by rearrangement to give 1(2)-hydroxymethyl-3(5)-pyrazolecarboxylic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1182–1184, September, 1985.  相似文献   

16.
7,7-Dichloro-2,2-dicarbethoxybis (5-indolyl) methane has been synthesized by cyclization of the 3,3-dichloro-4,4-diphenylmethanedihydrazone of ethyl pyruvate. Subsequent hydrolysis and decarboxylation of the corresponding diacid gave the unsubstituted 7,7-dichlorobis (5-indolyl) methane. The syn-syn, syn-anti, and anti-anti forms of 3,3-dichloro-4,4-diphenylmethanedihydrazone of ethyl pyruvate have been separated and characterized.For Communication 25, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1062–1065, August, 1988.  相似文献   

17.
Summary 7-(3,3-Dimethylallyloxy)-6-methoxycoumarin and two new coumarins — ramosin and ramosinin — have been isolated from the epigeal part ofHaplophyllum ramosissimum.On the basis of IR, PMR, and mass spectroscopy and chemical reactions, the structure of 8-(3,3-dimethylallyl)-7-(3,3-dimethylallyloxy)coumarin (II) has been proposed for ramosin and that of 3-(1,1-dimethylallyl)-8-(3,3-dimethylallyl)-7-methoxycoumarin (III) for ramosinin.Leningrad Sanitary-Hygienic Medical Institute. Institute of Chemistry, Academy of Sciences of the Turkmen SSR, Ashkhabad. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 15–17, January–February, 1979.  相似文献   

18.
Zusammenfassung Die Absorptionsspektren folgender Verbindungen: Chinoxalin, 2,2-Dichinoxalyl, 2-Methylchinoxalin, 3,3-Dimethyl-2,2-dichinoxalyl, Pyrazin, 2,2-Dipyrazyl, 2-Methylpyrazin und 5,5-Dimethyl-2,2dipyrazyl wurden in Methanol im Bereich von 225–360 nm bestimmt.Eine Methode zur quantitativen Bestimmung der genannten Verbindungen wurde ausgearbeitet, um den Herstellungsprozeß von 2,2Dichinoxalyl, 3,3-Dimethyl-2,2-dichinoxalyl, 2,2-Dipyrazyl und 5,5-Dimethyl-2,2-dipyrazyl aus den entsprechenden Monomeren durch direkte Photometrierung von Proben der Reaktionsgemische, die in einem beliebigen Stadium der Synthese dem Reaktor entnommen wurden, verfolgen zu können.
Spectrophotometric determination of dehydrocondensation products of pyrazines and quinoxalines
Summary The absorption spectra of the following compounds: quinoxaline, 2,2-diquinoxalyl, 2-methylquinoxaline, 3,3-dimethyl-2-2-diquinoxalyl, pyrazine, 2,2-dipyrazyl, 2-methylpyrazine and 5,5-dimethyl-2,2-dipyrazyl were determined in methanol in the region of 225–360 nm. A method was developed for the quantitative determination of these compounds in order to be able to follow the preparation methods of 2,2-diquinoxalyl, 3,3-dimethyl-2,2-diquinoxalyl, 2,2-dipyrazyl and 5,5-dimethyl-2,2-dipyrazyl from the corresponding monomers through direct photometration of samples of the reaction mixture, which can be taken from the reactor at a selected stage of the synthesis.
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19.
Nucleophilic addition of organometallic lithium and magnesium compounds to 1-alkyl-3-(2-quinolyl)quinolinium cations produces a mixture of the corresponding 1-alkyl-2-R-1,2-dihydro-2,3-biquinolyls and 1-alkyl-4-R-1,4-dihydro-2,3-biquinolyls. The portion of the latter decreases with increasing hardness of the organometallic compound.For No. 5, see [1].Stavropol State University, Stavropol'355009, Russian Russian Chemical Technology University Moscow 125190 Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 919–923, July, 1999.  相似文献   

20.
The isoflavin retusin, squalene, 3,4,5-trihydroxystilbene (resveratrol), 3,3,4,5-tetrahydroxystilbene, and a new compound constructed of fragments of retusin and 3,3,4,5-tetrahydroxystilbene have been isolated for the first time from an ethanolic extract of the heartwood ofMaackia amurensis Rupr. et Maxim (Fabaceae) growing in Maritime Territory. The high-molecular-weight polyphenols that impart the characteristic coloration to macckia wood are present in an amount of 7%. The majority of the phenolic compounds isolated showed a high antiradical and antioxidant activity.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 775–781, November–December, 1985.  相似文献   

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