Mass spectra of some N-amino compounds

N-amino compounds on electron-impact commonly lose NH from the molecular ion, and frequently lose N, NH₂ and NH₃. This behaviour contrasts with C-amino compounds which mainly lose HCN and H₂CN. The mass spectra of eight N-amino compounds are recorded and discussed, together with some data from literature sources.     

Synthesis of hydroxybenzaldehyde derivatives containing an isoxazole heteroring

5-Phenyl(p-tolyl)isoxazole-3-carboxylic acids were synthesized starting from 3-hydroxyiminomethyl-5-phenyl(p-tolyl)isoxazoles, and their reactions with p-hydroxybenzaldehyde, vanillin, isovanillin, o-vanillin, and ethyl vanillin gave the corresponding esters. The latter were brought into condensation with aromatic amines to obtain Schiff bases which were reduced to amines.     

Isoxazole derivatives in the synthesis of bifunctional compounds by cleavage of the heteroring (review)

The pathways and methods of transformation of isoxazoles to give various acyclic difunctional derivatives (-cyano ketones, -diketones, imino and amino ketones, -amino alcohols, ,-unsaturated ketones, etc.) by opening of the heteroring are examined in the review from the point of view of latent functionality. The prospects for the application of acyclic functional derivatives of isoxazoles and 2-isoxazolines — adducts of 1,3-dipolar cycloaddition of nitrile oxides to olefins and acetylenes — for regio- and stereospecific synthesis are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1155–1173, September, 1981.     

Resonance-stabilized α-naphthylmethyl carbocations and spiro compounds based thereon: VII. Transformations of α-naphthylmethyl carbocations stabilized by one electron-donor group or peri-fused heteroring

1-Hydroxymethyl-and 1-alkoxymethylnaphthalenes containing dimethylamino and methoxy groups or a heteroring in positions 4 and 5 react with protic and Lewis acids to give 1-naphthylmethyl carbocations. Reactions of the latter with the initial alcohol molecule lead to the formation of oligomerization or dehydrogenation (to aldehyde) products or the corresponding dinaphthylmethanes. In some cases, the process was accompanied by cyclodimerization to form cyclohexadienone spiro derivatives in a small yield.     

Mutual effect of elements in the separation by sublimation of their chlorides

The transfer and separation of the chlorides of a number of rare-earth and actinide elements and their mixtures has been investigated in the flow of gas-carrier along a quartz tube under temperature gradient. The dependence of the position (characteristic temperature) and shape of the condensation (or sorption) peak of cerium chloride in the gradient region of the tube on the amount of substance in the starting zone has been studied. Weight limits determining the behaviour of the substance as micro- or macrocomponent and its transfer by adsorption or condensation mechanism have been established. The mutual effect of elements in the La?Ce, Am?U, Np?U systems has been studied. It is shown that in the case, when the condensation peak of the macrocomponent overlaps the adsorption zone of the microcomponent, the position of the adsorption peak is shifted and the effectivity of the micro- and macrocomponent separation deteriorates in comparison with the separation of microamounts of elements. If the condensation of the macrocomponent occurs in temperature zones distant from that of the microcomponent adsorption, the position of the latter does not change and the degree of purification of the microcomponent increases.     

The t-butyl group as sensor group of the ortho effect

The ¹³C chemical shift difference between the Me group C atoms and the quaternary C atom of the t-Bu group in 58 p-, m- and o-substituted t-butyl-benzenes has been measured and analysed in terms of inductive. mesomeric and proximity effects. It is shown that the ortho effect is too complex to justify a unified explanation by a correlation treatment.     

Mutual effect of the interaction of human serum albumin with cellulose in water

Adsorption of human serum albumin to microcrystalline cellulose interface has been determined as functions of protein concentration and pH of the aqueous solutions. The maximum adsorption value is reached at the protein isoelectric point. The study of adsorption at several values of pH indicates that its interaction with the MCC interface is not controlled by the electrostatic effect. The FTIR, ¹³C NMR data reveal that human serum albumin denaturates at its IEP and its macromolecules become extended. Resulting intercalates consist of microcrystalline cellulose, albumin, and solvent.     

Mutual effect of benzene and maleic anhydride in selective heterogeneous catalytic oxidation of benzene

It is shown that in the oxidation of benzene (B) by molecular oxygen over a vanadium-molybdenum oxide catalyst the introduction of maleic anhydride (MA) into the reaction mixture suppresses the formation of carbon oxides but does not alter the rate for formation of MA from B. It has been found by programmed thermal desorption that B and MA are adsorbed at different active sites on the catalyst.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 24, No. 5, pp. 622–626, September–October, 1988.We thank Yu. I. Pyatnitskii for discussion of the paper.     

Mutual effect of ligands in complexes of nontransition elements with octahedral environment in the central atoms

M. V. Lomonosov Moscow State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 6, pp. 112–118, November–December, 1988.     

Investigation of the electronic effect of the diphenylphosphino group

We have synthesized meta-substituted derivatives of benzoic acid, determined their ionization constants in water-alcohol solutions of concentration 11 and 14 by volume, and calculated the Hammett constant _m of the diphenylphosphino (0.12), diphenylamino (–0.04), diphenylphosphinyl (0.40) and diphenylthiophosphinyl (0.32) groups. Unlike the diphenylamine group, the diphenylphosphino group is metaorienting, which is probably to be explained by the absence or the weak nature of p- conjugation of incomplete electron pairs on the phosphorus and the presence of an electron-acceptor effect (d-p conjugation).