Structure and reactivity of the condensation products of aromatic amines with aliphatic aldehydes

A number of previously undescribed propylidenearylamine dimers have been synthesized by the interaction of propionaldehyde with a series of para-substituted anilines(R=H, CH₃, OCH₃, F, Cl, Br, I) and with-naphthylamine. The structure of the bis-propylidenearylamines has been established by a study of their IR and UV spectra. It has been shown that all the bis-propylidenearylamines, except for bis(propylidene-p-fluoroaniline), have the structure of 2-ethyl-3-methyl-4-arylamino-1, 2, 3, 4-tetrahydroquinolines. The dipole moments of the bis(propylidene-p-R-anilines) have been determined. Comparison of the values obtained with the calculated values indicates that the most favorable molecular conformation of the bispropylidenearylamines is a tetrahydroquinoline half-chain with quasi-equatorial positions for the 4-NHAr and NH groups and an equatorial 3-CH₃ group. In contrast to the bis-ethylideneanilines, we did not succeed in finding other stable conformers for the bis-propylidene derivatives. It has been established that bis (propylidene-p-fluoroaniline) has the 1, 3-bis (p-fluorophenylamino)-2-ethyl-1-hexene structure.For communication VI, see [1].     

Tautomeric equilibrium of 1-β-D-ribofuranosyl-2-keto-4-(n-methoxyamino)pyrimidine

The 1-β-D-ribofuranosides of 2-keto-4-(N-methoxyamino)pyrimidine, 2-keto-4-(N-methyl-N-methoxyamino)pyrimidine, and 2-keto-3-methyl-4-(N-methoxyamino)pyrimidine were synthesized, and their pK_a values were determined by spectrophotometry. The pK_a values of the compounds are evidence that the tautomeric equilibrium between the oxime and hydroxyamine forms of 1-β-D-ribofuranosyl-2-keto-4-(N-methoxyamino)pyrimidine in aqueous solutions is shifted to favor the oxime form (K_T?25).     

Ionotropic reactions of β-sultones

The reaction mechanism of-sultones are discussed; a scheme for the reactivity is proposed. Polyfluoro--sultones can undergo anionotropic reactions of the type Hydrogeneous-sultones under prototropic reactions:     

Reaction of bis(triethylgermyl)mercury with mercurated acid nitriles

Conclusions The exchange reaction of the radicals between bis(triethylgermyl)mercury and mercury derivatives R₂Hg (R=C(Me₂)CN, C(CF₃)₂CN, CH(CN)₂) leads to the formation of unstable Et₃GeHgR compounds. The composition of the decomposition products of these compounds depends on the nature of R.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2800–2802, December, 1977.     

Nitropyrazoles

A method for the synthesis of bi-, ter-, and quaterpyrazoles by cyclization ofC-(diformylmethyl)nitropyrazoles with hydrazine has been elaborated. Some of theirC- andN-derivatives have been obtained. The compounds prepared have been characterized by¹H,¹³C,¹⁴N, and¹⁵N NMR spectra.For communication 6, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1941–1945, November, 1993.     

Screening of psychotropic drugs in human hair based on high-performance thin-layer chromatography and microliquid extraction

The monitoring of the physiological and functional state of personnel from dangerous industries is very important for the ensuring of ecological security. Usually, this involves testing for the consumption of alcohol and drugs of abuse. During the last several years the use of legal psychotropic drugs has increased and the control over these drugs has became an actual problem. As is well known, the long-term history of drugs present in the body is accessible through hair analysis. This is why the aim of our research is to create a screening procedure based on coupling high-performance thin-layer chromatography with microliquid extraction as a psychotropic drug testing method for hair. Some widely distributed antidepressants, neuroleptics, and sedative drugs are chosen for research. The optimal experimental conditions for all of the consequent steps for the screening detection of the model samples are determined. The visual and densitometric detection limits allow for the employment of the proposed technique for a fast and cost-effective analysis of the drugs of abuse.     

Effect of Ultrasonic Field on the State of Starch Hydrogels

Some fundamental aspects of how the primary structure of starch hydrogels with concentration of 1 to 8 wt % disintegrates in an ultrasonic field are discussed. The effect of ultrasonic vibrations on the basic characteristics of starch hydrogels: degree of grain cleavage, viscosity, transparence, and phase composition, is analyzed.     

Synthesis and structure of copper(II) complexes with diaminodioxime (H<Subscript>2</Subscript>L), a derivative of the monoterpenoid (+)-3-carene

Copper(II) compounds with the optically active diaminodioxime (H₂L) derived from the monoterpenoid (+)-3-carene, Cu(H₂L)(NO₃)₂ H₂O (I), Cu(H₂L)(ClO₄)₂ H₂O (II), Cu(H₂L)Br₂ H₂O (III), and Cu(H₂L)SO₄0.5H₂O (IV) with µ_eff equal to 1.81, 1.79, 1.71, and 1.8 µ_B, respectively, were prepared. Studies of the complexes by IR and EPR spectroscopy showed that I and II are mononuclear ionic complexes. Compound III apparently has polymeric structure (the CuN₄Br₂ coordination unit). According to EPR data, the Cu²⁺ ions in polycrystalline compounds III and IV undergo exchange interactions.Translated from Koordinatsionnaya Khimiya, Vol. 30, No. 12, 2004, pp. 897–900.Original Russian Text Copyright © 2004 by Larionov, Myachina, Sheludyakova, Boguslavskii, Tkachev, Bizyaev.     

Synthesis and properties of amides of 2-substituted 3-aryl- and 3-pyridylaminoacrylic acids

The reaction of aryl- or pyridylamines with ethyl orthoformate and malonanilic acid gave amides of 2-(N-arylcarbamoyl)-, 2-cyano-, 2-ethoxycarbonyl-3-arylaminoacrylic acids and their corresponding 3-pyridyl analogs. IR and PMR spectroscopy indicates that these compounds exist in the enamine form with strong intramolecular hydrogen bonds. Amides of 3-(2-pyridylamino)-2-ethoxycarbonylacrylic acid cyclize to give amides of pyrido[1,2-a]pyrimidine-3-carboxylic acid, which react with hydrazine hydrate to give amides of 3-aminopyrazole-4-carboxylic acid.Perm Pharmaceutical Institute, 614000 Perm. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 629–633, May, 1994. Original article submitted February 8, 1994.     

Stereoisomerism of N-(1-Propenyl)thiobenzamide

A prototropic rearrangement of N-prop-2-enylbenzocarbothioamide afforded two stereoisomeric N-prop-1-enylbenzocarbothioamides (IIa, b) isolated as individual compounds. The stereoisomerism is due to hindered rotation around thioamide bond C(S)-N and also to -diastereoisomerism. The configuration of the isolated isomers was investigated by IR spectroscopy, AM1 and PM3 methods. In the molecules occurs the p,-conjugation with participation of nitrogen atom and multiple bonds resulting in formation of a united delocalized MO in the planar fragment C(S)-NC = C.