Synthesis,structure, and chemical properties of some N-(3-chloro-2-quinoxalyl)arylsulfonamides

We have developed a method for synthesis of N-(3-clzloro-2-quinoxalyl)sulfonamides by reaction of 2,3-dichloroquinoxaline with substituted arylsufonamides. Based on the IR spectra, we have established that in the solid state, the synthesized compounds exist in the form of amide tautomers. Alkylation of these compounds leads to N-metliyl-N-(3-chloro-2-quinoxalyl)arylsulfonamides. We demonstrate the possibility of nucleophilic substitution of the halogen upon treatment with O- and N-nucleophiles. The use of bifunctional nucleophiles leads to condensed quinoxalines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 30, No. 3, pp. 387–392, March, 1994.     

O-Alkylation of furan and thiophene ketoximes in conditions of interphase catalysis in a liquid/solid system

Alkylation of 2 furanyl- and 2-thienylalkyl ketoximes with alkyl, allyl, and propargyl halides in the two phase catalytic system sol. K₂CO₃/C₆H₆/18-crown-6 at room temperature causes the formation of mixtures of E- and Z-isomers of the corresponding O-ethers with yields of 32–74%. Partial E/Z-isomerization takes place during the reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 18–23, January, 1994.     

Hydroxyl-containing mesogens. Synthesis and liquid-crystalline properties of 2-o-hydroxyarylpyrimidines

We have synthesized 5-alkyl(alkoxy)-2-(o-lzydroxy-p-alkoxyphenyl)pyrimidines and considered the effect of the OH group on the inesomorphism. We have found that in binuclear o-hydroxyarylpyrimidines, an ortho OH group forming an intramolecular hydrogen bond increases T_mp, inhibits the appearance of nematic properties, and promotes the appearance of a smectic A.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 30, No. 1, pp. 90–92, January, 1994.     

Synthetic analogs of natural flavolignans. V. A new synthesis of 6-halogeno-1,3-benzodioxane analogs of silandrin and hydnocarpin

6-Halogeno-1,3-benzodioxane analogs of chalcones have been synthesized by various methods. Flavanone and flavone analogs of silandrin and hydnocarpin have been obtained from them. The structures of the new flavonoids have been shown by their PMR spectra.     

Some kinetic features of the hydrolysis of protopectin

Some features of the kinetics of the hydrolysis of apple protopectin have been studied on the basis of an analysis of monosaccharide residues of the pectin substances and determinations of characteristic viscosity. It has been shown that the fine regulation of the physicochemical parameters of the hydrolysis of protopectin leads to the formation of pectin substances with different properties.     

Luteolin glucosides fromFerula varia

Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 891475. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 679–680, September–October, 1994.