Fourier transform 13C nuclear magnetic resonance studies of steroids—II : Derivatives of 17β-(2,5-dihydro-5-oxo-3-furyl)-3β,5α,6-trihydroxyandrostane

The natural abundance ¹³C NMR spectra of derivatives of 17β-(2,5-dihydro-5-oxo-3-furyl)-3β,5α,6-trihydroxy androstane have been measured and completely assigned. The substituent chemical shifts (S.C.S's) for 11α- and 17α-OH substitution are evaluated. The magnitude and sign of the S.C.S.'s are discussed and compared with previous results from the literature.     

2-(5-Bromo-2-furyl)quinoxaline and 3-(5-bromo-2-furyl)-2-quinoxalone

2-(5-Bromo-2-furyl)quinoxaline and 3-(5-bromo-2-furyl)-2-quinoxalone were obtained by the action of bromine on the corresponding quinoxaline derivatives and also by condensation of o-phenylenediamine with, respectively, (5-bromo-2-furyl)glyoxal or (5-bromo-2-furyl)glyoxylic acid esters.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 404–406, March, 1973.     

2-Polyfluoroalkylchromones. 14. Synthesis of 4-chloro-3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles

3-Chloro-2-polyfluoroalkyl- and 3-chloro-6-nitro-2-polyfluoroalkylchromones were synthesized. These compounds react with N₂H₄·2HCl on boiling in ethanol to form 4-chloro-3(5)-(2-hydroxyaryl)-5(3)-polyfluoroalkylpyrazoles.     

Analogs of pyrimidine nucleosides. 17. Synthesis of 1-[5(2)-fluoromethyltetrahydro-2-furyl]uracils

The synthesis of 2-fluoromethyltetrahydrofuran is described, and it is shown that chlorination of the latter gives 2-chloro-5- and 2-chloro-2-fluoromethyltetrahydrofurans in a ratio of 5:1. 2,4-Bis(trimethylsilyl) derivatives of uracil were alkylated by means of the mixture of -chloro ethers without separation, and a mixture of the cis and trans isomers of 1-(5-fluoromethyltetrahydro-2-furyl)uracils and 1-(2-fluoromethyltetrahydro-2-furyl)uracils were obtained. The reaction products were identified on the basis of the PMR spectra.See [1] for communication 16.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 256–259, February, 1982.     

Synthesis and properties of 5-(5-nitro-2-furyl)thiazolines

The reactions of 2-amino-4-methyl-5-(5-nitro-2-furyl)thiazole with excess methyl iodide leads to 3,4-dimethyl-2-methylamino-5-(5-nitro-2-furyl)thiazolium iodide, which is converted to 2-imino-3,4-dimethyl-5-(5-nitro-2-furyl)thiazoline under the influence of bases. The iminothiazoline structure was proved by comparison of the spectral characteristics of its acetyl derivative and the isomeric 2-(N-acetyl-N-methyl) amino-4-methyl-5-(5-nitro-2-furyl)thiazole. The pKa values of 2-amino-4-methyl-5-(5-nitro-2-furyl)thiazole and 3,4-dimethyl-2-imino-5-(5-nitro-2-furyl)-thiazoline were determined, and the constant of the aminothiazole-iminothiazoline tautomeric equilibrium was calculated.Translated from Khimiya Geterosiklicheskikh Soedinenii, No. 10, pp. 1337–1340, October, 1985.     

Synthesis of 9-(5-Pentyl-2-furyl)nonanoic Acid

Recently,severalkindsoftotalsyntheticmethodsfornaturallyoccurringfuranoidfattyacids(F-acids)whichhavemanybiologicalactivities1havebeendeveloped2.Inthepresentpapertheauthorswishtoreportanewsimplerouteofsynthesizing9-(5-pentyl-carbomethoxyheptyl)triphenylphosphoniumbromideinthepresenceofpotassiumcarbonateandl,2-butyleneoxideinanunexpectedlylowyield(34%),mainlyduetotheextremelyunstablecharacterof2inbasicconditions,especiallyforstrongbaselikesodiummethoxidewhichgaverisetoconsiderableresinification…     

The synthesis of N-substituted β-(5-amino-2-furyl) nitroolefins

Studying nucleophilic substitution reactions in a number of β-(5-halo-2-furyl) nitroolefins (I) with secondary amines, we have shown for the first time the possibility of synthesizing the previously unknown N-substituted β-(5-aminofuryl)nitroolefins (II). We have found that the smoothest substitution reaction takes place in the case of the 5-halo-furylnitropropenes (I, R=CH₃) with morpholine and methylaniline when their alcoholic solutions are heated.     

3-（2-呋喃基）-4-芳基-1，2，4-三唑啉-5-硫酮的合成及生物活性

1-（2-呋喃甲酰基）-4-芳基氨基硫脲经过环化反应，制备了一系列新的化合 物3-（2-呋喃基）-4-芳基-1，2，4-三唑啉-5-硫酮类化合物，并通过元素分析和 IR，^1H NMR等波谱数据确证了上述化合物的结构。初步的生物活性实验表明其中 有些化合物的具有非常好的植物生长调节活性。     

Synthesis of 1-(2-furyl)-2-nitropropen-3-ones

1-(2-Furyl)-2-nitropropen-3-ones were synthesized by reaction of nitrogen tetroxide with a number of , -unsaturated furylcarbonyl compounds. The 5-nitrofuryl derivative was obtained from 1-(2-furyl)-3-(4-methoxyphenyl)propen-3-one when the excess amount of N₂O₄ was increased. Replacement of bromine by a nitro group in the furan ring is observed in the case of the 5-bromofuryl derivative.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1604–1606, December, 1977.     

Asymmetric synthesis of (-)-nupharamine and (-)-(5S,8R,9S)-5-(3-furyl)-8-methyloctahydroindolizidine from beta-amino ketones and the intramolecular Mannich reaction

The asymmetric synthesis of the 2,3,6-trisubstituted piperidine core of the antitumor Nuphar alkaloids was readily achieved by using the intramolecular Mannich reaction and a sulfinimine-derived beta-amino ketone.     

S-alkylthiosemicarbazonium salts in the synthesis of 1,2,4-triazolines. Molecular structure of 1,4-diacetyl-3-(5-nitrofurfurylthio)-5-(2-furyl)-δ2-1,2,4-triazoline

Acylation of S-alkylthiosemicarbazonium salts with acetic anhydride leads to the formation of 1,4-diacetyl-²-1,2,4-triazolines. It was also demonstrated, based on x-ray structural analysis, that the triazoline ring in the molecular structure of 1,4-diacetyl-3-(5-nitrofurfurylthio)-5-(2-furyl)-²-1,2,4-triazoline exists in an envelope or bent conformation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 931–937, July, 1990.