Structure of phenolic stabilizers for polymers VIII. Crystal structure of 2,2′-methylenebis(4-methyl-6-ter-butylphenol) monoacrylate

L. Ya. Karpov Scientific-Research Physicochemical Institute. Scientific-Research Institute of Rubber and Latex Goods. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 5, pp. 162–164, September–October, 1991.     

A study of 1,2,3,4-tetrahydro-4-azafluorene-3,9-diones

Intramolecular cyclization of the diamides and N,N-dimethylamides of -[indan-1,3-dion-2-yl]benzylmalonic acids (I) has given 1-aryl-2-carbamoyl-1,2,3,4-tetrahydro-4-azafluorene-3, 9-diones and 1-aryl-4-methyl-2-methylcarbamoyl-1,2,3,4-tetrahydro-4-azafluorene-3,9-diones (II). The structure of compounds II was shown by chemical methods: bromination, xanthylation, and hydrolysis in alkaline and acid media, and also by a study of IR and UV spectra.     

Microwave-assisted synthesis of sulfide M2S3 (m = Bi, Sb) nanorods using an ionic liquid

Single-crystalline Bi(2)S(3) and Sb(2)S(3) nanorods have been successfully synthesized by the microwave-assisted ionic liquid method. The starting reagents were Bi(2)O(3) or Sb(2)O(3), HCl, Na(2)S(2)O(3), and ethylene glycol (EG) or ethanolamine, and the ionic liquid used was 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF(4)]). Our experiments showed that the ionic liquid played an important role in the morphology of M(2)S(3) (M = Bi, Sb). Single-crystalline Bi(2)S(3) nanorods could be prepared in the presence of [BMIM][BF(4)]. However, urchinlike Bi(2)S(3) structures consisting of nanorods were formed without using [BMIM][BF(4)]. Single-crystalline Sb(2)S(3) nanorods were obtained in the presence of [BMIM][BF(4)]. However, single-crystalline Sb(2)S(3) nanosheets could be prepared in the absence of [BMIM][BF(4)]. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and electron diffraction (ED).     

Free radicals in electrochemical reduction of 3,5-dicarbethoxy-1,4-dihydropyridines with nitrophenyl groups in positions 2, 4, and 6

In the electrochemical reduction of 2,6-bis- and 2,4,6-tris(nitrophenyl) derivatives of 3,5-dicarbethoxy-1,4-dihydropyridine, in the first stage, one of the para-nitrophenyl groups in position 2 or 6 of the heterocycle is reduced. Free radicals have been obtained and identified, the primary species being ion radicals of the nitrophenyl type. The presence of the heterocycle in the molecule of the 1,4-dihydropyridine derivative stabilizes secondary free radicals of the nitrosophenyl type. In the process of electrochemical reduction, no evidence has been found of any intramolecular transfer of electrons or protons from the dihydropyridine part of the molecule to the nitrophenyl groups. Derivatives of 2,6-bis(p-nitrophenyl)-3,5-dicarbethoxy-1,4-dihydropyridine have been synthesized, and the oxidation and methylation of these derivatives have been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 481–487, April, 1991.     

Fragmentation of the unsubstituted carbohydrate units of cardenolide monosides

In the mass spectra of unsubstituted monosides of cardenolide nature are observed the M⁺ peaks, and also, in each case, three characteristic processes of the fragmentation of the carbohydrate unit. The formation of the ions AglOCH=OH⁺ is the most universal property of these compounds. The stability of ions of the type under consideration depends on the nature and position of attachment of the sugar residue and on the number of polar groups in the aglycone. The laws of the fragmentation of the carbohydrate unit are extended to the spectra of glycosides of other classes.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodynykh Soedinenii, No. 3, pp. 345–354, 1983.     

Synthesis and transformations of 2-(2-furyl)-and 2-[β;-(2-furyl)vinyl]naphth[1,2-d]imidazoles

The corresponding 2-(2-furyl)naphth[1,2-d]imidazoles were obtained by heating Schiff bases, prepared from 1,2-naphthalenediamine and furfural and 5-bromo- and 5-nitrofurfurals, in nitrobenzene. 2-[-(2-Furyl)vinyl]naphth[1,2-d]imidazoles were synthesized by condensation of 2-methylnaphth[1,2-d]imidazole with furfural and 5-bromo- and 5-nitrofurfural. The methylation, nitration, and acetylation of the compounds obtained were studied, and the replacement of the bromine atom in the furan ring by a nitro group was also investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1555–1557, November, 1972.     

Synthesis of New Difurocoumarins

5,7-Dihydroxy-4-methyl- and 5,7-dihydroxy-4-trifluoromethylcoumarins are starting compounds in the synthesis of new 10-methyl-8H-difuro[2,3-f;2,3-h]-8-ones and 10-trifluoromethyl-8H-difuro-[2,3-f;2,3-h]chromen-8-ones with high yields.     

Potentiometric titration of peptides and the starting materials and intermediates of their synthesis. I. Acidimetric determination of N-acetylamino acids

The potentiometric titration of N-acetylamino acids and their sodium salts in nitromethane-acetic anhydride (2:1) with a nitromethane solution of perchloric acid has been investigated. A procedure has been developed for the quantitative determination of N-acetylamino acids in the presence of acetic acid in aqueous solutions. A differentiation determination of N-acetylamino acids and their salts in the presence of sodium acetate has been carried out.     

Interaction of Nitromethane with Modified Paramagnetic Defects on a Thermochemically Activated Silica Surface

It was found that the interaction of the modified paramagnetic defects SiO(CH₂) _n H₂ (n = 0.1) with nitromethane on a thermochemically activated silica surface at 300 K results in the formation of the following nitroxyl radicals: SiO(CH₂) _n CH₂ON( )CH₃ and SiO(CH₂) _n CH₂N( )CH₃. It was suggested that these radicals are the products of two different reactions of the modified paramagnetic defects: the first results from a reaction with free nitromethane; the second, from a reaction with nitromethane bound as complexes with diamagnetic surface defects.     

A study of deuterium exchange in adamantane carboxylic acids and alcohols under electron impact

The mass spectra of 1-adamantyl substituted carboxylic acids and alcohols with and without deuterated hydroxyl groups were studied. Deuterium exchange between functional group and adamantane nucleus was observed and a possible explantation of the phenomenon is given.