Dual Mechanism of Enamine-enamine Rearrangement of 1,3-diaryl-3-(1-imidazolyl)propen-2-ones

The formation of 1,3-diaryl-3-(1-imidazolyl)propen-1,3-diol that is an intermediate of enamine-enamine rearrangement of 1,3-diaryl-3-(1-imidazolyl)propen-1-ones constitutes the key stage of the dual mechanism of the rearrangement proper. The reaction of 1,3-diaryl-2,3-dibromopropan-1-ones with a primary amine provides 1,3-diaryl-3-iminopropan-1-ones as a result of enamine-imine prototropic rearrangement.     

Mass-spectrometric study of physiologically active β-thiosemicarbazones of N-alkylisatins

The molecular ions of isatin (I) and N-methyl- (II) and N-ethylisatin (III) -thiosemicarbazones undergo fragmentation via many pathways with the elimination of NH₃, H₂S, CO, CH₂N₂, CHN₃, CH₂N₂S, CH₂NS, and CHNS particles; this is due to primary localization of the charge on the heteroatoms of the thiosemicarbazone residue. A previously unknown rearrangement, which consists in migration of an HS group to the -carhon atom of the heteroring with subsequent ejection of a CHN₃ fragment. The [M — CO]⁺ ions undergo fragmentation with the elimination of CH₂N₂S; in the case of II and III fragmentation is preceded by detachment of a hydrogen atom (II) or a methyl group (III) from the substituent attached to the ring nitrogen atom. The [M — CO, -H, -CH₂NS]⁺ (II) and [M — CO, -CH₃, -CH₂N₂S]⁺ (III) ions undergo fragmentation with the ejection of HCN in two ways through both the ring nitrogen atom and the thiosemicarbazone residue. Schemes for the principal pathways of fragmentation and rearrangements are presented. The compositions of the ions were confirmed by the high-resolution mass spectra and the mass spectra of the N-deuteroalkyl derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 75–79, January, 1979.     

13C NMR spectra of some 1,2-disubstitutedN-vinyl-1H-1,2,4-triazoles

¹³C NMR spectra (20 and 75 MHz, in DMSO-d₆) of a series of 1,3-diaryl-3-(1H-1,2,4-triazol-1-yl)- and 1,3-diaryl-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-ones were registered. It was shown that the chemical shifts of both the carbon atom of the alkene group and C(3) reflect regio- and stereoisomerism of these compounds. Taking this into account the isomeric structures of several 1,3-diaryl-3-(1H-1,2,4-triazol-1-yl)prop-2-en-1-ones were identified and the configurations relative to the double bond of a number of 1,3-diaryl-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-ones were determined.     

Mass spectrometric study of isatins II. N-propyl(allyl,propargyl)isatins

The mass spectra of N-propyl- (I), N-allyl- (IV), and N-propargylisatin (VII) and their 5-methyl (II, V, VIII) and 7-methyl (III, VI, and IX) derivatives were recorded. It is shown that a portion of the [M-2CO]⁺ ions in the mass spectra of N-propargylisatins undergo rearrangement to give ions with a quinoline structure. A scheme for the fragmentation of the investigated compounds is presented. The mass spectra of the 5- and 7-methyl derivatives are compared.See [1] for communication I.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 639–641, May, 1977.     

N-alkylation of trimethylsilyl derivatives of isatin with halomethyl ketones

Trimethylsilyl derivative of isatin react with halomethyl ketones at the nitrogen atom in contrast to sodium salt of isatin, which reacts with these compounds at heterocyclic carbon atom. Institute for the Biological Protection of Vegetation, Academy of Sciences of Moldova, 2058, Moldova. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1345–1346, October, 1999.     

Indoledione-indole rearrangement (review)

The indoledione-indole rearrangement, which occurs during the basic condensation ofortho-aminophenylcarbonyl compounds (ortho-aminophenylglyoxylic acid,ortho-aminoketones) with halomethylketones, is reviewed.Institute of Biological Plant Protection, Academy of Sciences of the Moldavian Republic, Kishinev 2058. Translated from Khimiya Geteorotsiklicheskikh Soedinenii, No. 9, pp. 1170–1180, September, 1998.     

Rearrangement of 1-[2-oxoalkyl(aryl)]indole-2,3-dione to form 2-acylindolyl-3-carboxylic acid

It has been shown that 1-[2-oxoalkyl(aryl)]indole-2,3-diones are recyclized under the influence of sodium alcoholate to form 2-acylindolyl-3-carboxylic acids. A reaction scheme is proposed for this rearrangement.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 29, No. 5, pp. 642–647, May, 1993.