Reaction of primary and secondary enamines with anhydrides of unsaturated dicarboxylic acids

It was established that donor-acceptor complexes are formed in the reaction of some conjugated enamines with anhydrides of unsaturated dicarboxylic acids; in all likelihood, this constitutes evidence in favor of a scheme that includes nucleophilic addition of the enamine to the double bond. Addition of this type with subsequent intramolecular cyclization leads to the formation of ²-pyrrolin-5-ones. In the case of citraconic anhydride it is shown (on the basis of data from the PMR and mass spectra) that nucleophilic attack is directed to the unsubstituted carbon atom of the ethylene bond.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 474–476, April, 1977.     

Synthesis of some pyrimido[4,5-b][1,4]oxazines starting from 5-aminopyrimidines

Derivatives of pyrimido[4,5-b] [1,4]oxazine with hydroxy-, chloro-, and substituted amino groups at the 4-position were synthesized. The structures of the compounds were confirmed by mass-spectrometry and by alternate synthesis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 974–976, July, 1985.     

Reactions of (1-Bromoethenyl)(diphenyl)phosphine Oxide with NH-, OH-, and SH-Nucleophiles

Russian Journal of General Chemistry - The reactions of (1-bromoethenyl)(diphenyl)phosphine oxide with NH-, OH-, SH-nucleophiles were studied. The reaction of phosphine oxide with alcohols and...     

Cyclopropanation of 2-arylmethylidenemalononitriles,alkyl 3-aryl-2-cyanoprop-2-enoates,and N-substituted 3-aryl-2-cyanoprop-2-enamides with bromine-containing zinc enolates

Zinc enolates derived from 2,2-dibromoindan-1-one and 2,2-dibromo-1,2,3,4-tetrahydronaphthalen-1-one reacted with 2-arylmethylidenemalononitriles, alkyl 3-aryl-2-cyanoprop-2-enoates, and N-substituted 3-aryl-2-cyanoprop-2-enamides to give, respectively, 3-aryl-1′-oxo-1′,3′-dihydrospiro[cyclopropane-1,2′-indene]-2-2-dicarbonitriles, 3-aryl-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2,2-dicarbonitriles, alkyl 3-aryl-2-cyano-1′-oxo-1′,3′-dihydrospiro[cyclopropane-1,2′-indene]-2-carboxylates, alkyl 3-aryl-2-cyano-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2-carboxylates, and N-substituted 3-aryl-2-cyanol-1′-oxo-3′,4′-dihydro-1′H-spiro[cyclopropane-1,2′-naphthalene]-2-carboxamides as a single diastereoisomer. The stereoconfiguration of the products was determined by ¹H and ¹³C NMR spectroscopy.     

Investigation of structural changes of paint-and-varnish copolymers under influence of ageing

Paintwork materials applied as coatings protecting from rust and corrosion suffer with time structural changes leading to worsening of their physical and mechanical characteristics. We study by X-ray diffraction technique the inner structure of a new modified silicate coating depending on its ageing. It is shown that new crystalline formations appear with ageing in samples worsening significantly their service properties.