The Influence of Silicon Dioxide on the Stability of the Phase Composition and Mechanical Properties of Alumina-Toughened Zirconia-Based Ceramics

Technical Physics - The influence of SiO2 impurity (with a concentration varying from 0 to 10 mol %) on the stability of tetragonal ZrO2 (t-ZrO2) and on a set of micro- and macromechanical...     

Pyrroloindoles. 6. New synthesis of 1H, 5H-pyrrolo[2,3-f]indole and 3H,6H-pyrrolo[3,2-e]indole

Ethyl pyruvate 1-acetyl-5-indolinylhydrazone was obtained by diazotization of 1-acetyl-5-aminoindoline with subsequent reduction of the diazonium salt and condensation of the hydrazine with ethyl pyruvate. A mixture of hydrogenated derivatives of linear and angular pyrroloindoles is formed as a result of cyclization of the hydrazone in polyphosphoric acid esters. Subsequent hydrolysis, decarboxylation, and dehydrogenation lead to 1H,5H-pyrrolo[2,3-f]indole and 3H,6H-pyrrolo-[3,2-e]indole.See [1] for Communication 5.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 504–507, April, 1982.     

Synthesis of Pyrrolo[a]- and Pyrrolo[c]phenanthridine Derivatives and Indolinyl and Indolylsubstituted 6-Phenanthridines

The corresponding Mannich bases have been synthesized by the aminomethylation of 6-methyl-1H-pyrrolo[2,3-a]- and 4-methyl-3H-pyrrolo[3,2-c]phenanthridinium iodides. The interaction of 6-chloro-phenanthridine with indoline and with 5-amino-N-acetylindoline gave the corresponding derivatives of phenanthridine. 6-(1-Indolyl)phenanthridine has been obtained by the dehydrogenation of 6-(1-indolinyl)phenanthridine with manganese dioxide.     

Pyrroloindoles. 8. Electrophilic substitution in the 1H,5H-pyrrolo[2,3-f]indole and 3H,6H-pyrrolo[3,2-e]indole series

The principles of the electron density distribution in 1H,5H-pyrrolo [2,3-f]indole and 3H,6H-pyrrolo[3,2-e]indole molecules were determined on the basis of quantumchemical calculations. These results were confirmed by the results of the investigated electrophilic-substitution reactions. The reaction centers of these compounds proved to be the same positions as in indole, viz., the 3 and 7 and 1 and 8 positions, respectively. The impossibility of 1,8-disubstitution in the angular heteroring was demonstrated in the case of bulky substituents; this was explained by a steric effect.See [1] for communication 7.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1086–1091, August, 1983.     

Synthesis of indole sulfonamides

A preparative method is reported for the synthesis of indole sulfonamides from 3-indolesulfonyl chlorides and certain amines.     

Indole derivatives. 138. Synthesis of α-(5-indolyl)ethylamine and 5-(2-aminoethoxy)- and 5-(aminoethylthio)tryptamines

The reaction of 5-acetylindole with hydroxylamine with subsequent reduction of the resulting oxime gave -(5-indolyl)ethylamine. Coupling of 4-(2-phthalimidoethoxy)- and 4-(2-phthalimidoethylthio)phenyldiazonium chlorides with ethyl -acetyl--phthalimidovalerate, subsequent cyclization of the resulting hydrazones, hydrolysis, decarboxylation, and removal of the phthalyl protecting group led to the formation of 5-(2-aminoethoxy)- and 5-(2-aminoethylthio)tryptamines, respectively.For Communication 137, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 46–48, January, 1992.     

Indole derivatives. 128. Synthesis and properties of 5,6- and 4,5-ethylenedioxyindoles

Reaction of 3,4-ethylenedioxyphenyldiazonium chloride with ethyl 2-methylacetoacetate and subsequent cyclization of the 3,4-ethylenedioxyphenylhydrazone of ethyl pyruvate gives a 14 mixture of 4,5- and 5,6-ethylenedioxy-2-ethoxycarbonylindoles, respectively, from which 4,5- and 5,6-ethylenedioxyindoles are formed by subsequent hydrolysis and decarboxylation. Mannich and Vilsmeyer reactions as well as acetylation and azo coupling have been studied for 5,6-ethylenedioxyindole.For Communication 127, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1624–1628, December, 1986.     

Indole derivatives. 136. 4-, 5-, 6-, and 7-Nitro-3-indolesulfonic chlorides and sulfonamides

The reaction of nitroindoles with chlorosulfonic acid in the presence of sodium sulfate was used to synthesize 4-, 5-, 6-, and 7-nitroindole-3-sulfonyl chlorides. Under the influence of ammonia and several amines these compounds were convened to nitroindole-3-sulfonamides which were reduced with hydrazine hydrate in the presence of Raney nickel to the corresponding amines.See [1] for Communication 135.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1341–1345, October, 1990.     

Strength Properties of Zirconium Ceramics with Silica Additives Hardened with Alumina

Physics of the Solid State - The effect of Al2O3 and SiO2 admixtures on strength properties of calcia-stabilized zirconia ceramics is studied. Optimal ratios of the components of CaO–ZrO2 +...     

Electromagnetic emission in the development of macroscopically unstable plastic deformation of a metal

Electromagnetic emission accompanying the serrated deformation of the aluminum?magnesium alloy Al-6Mg has been revealed and studied experimentally. By means of high-speed video recording and a complex of methods for measuring the strain, load, and electric potential, it has been found that there is a relation between the electromagnetic emission signals and the dynamics of deformation bands. Possible mechanisms of the generation of electromagnetic signals have been discussed.