Vol 52, No 1 (2016)

Three-component condensation of dialkyl oxalates with alkyl acetates and alkyl methyl ketones in the presence of bases afforded 1-alkoxy(or 1,6-dialkoxy)-1,6-dioxoalka-2,4-diene-3,4-diolates. The product structure was discussed on the basis of their IR, ¹H NMR, and mass spectra.

Polyprenol isolated from spruce needles was subjected to phosphorylation and acylation. Its phosphorylation with hexaethylphosphorous triamide in dioxane afforded bis(polyprenyl) N,N-diethylphosphoramidite which was hydrolyzed to bis(polyprenyl) phosphonate. The latter can be used in the synthesis of prodrugs. The acylation of polyprenol with aromatic and heterocyclic carboxylic acid chlorides gave the corresponding esters as potential precursors of pharmacologically important compounds. The structure of the isolated compounds was confirmed by ¹H, ³¹P, and ¹³C NMR and IR spectra.

1,2,4-Trichlorotrifluorobenzene reacted with potassium hydrogen sulfide, potassium hydroxide, sodium isopropoxide, liquid ammonia, and ethyl cyanoacetate via nucleophilic substitution of one fluorine atom with predominant formation of the isomer in which the new substituent replaced fluorine atom in the 5-position.

Unsymmetrical polymethine dyes have been synthesized from 6-tert-butyl-4-methylthioflavylium perchlorates and nitrogen-containing heterocyclic aldehydes derived from julolidine and polyfluorinated triphenyl-4,5-dihydro-1H-pyrazoles. Spectral characteristics of the obtained compounds have been studied.

1-Methyl-2-(thiophen-3-yl)-1H-benzimidazole was synthesized by the Weidenhagen reaction, followed by N-methylation. Electrophilic substitution reactions of the title compound, in particular nitration, bromination, sulfonation, formylation, and acylation, were studied. The formylation and acylation in polyphosphoric acid afforded mixtures of 2- and 5-substituted isomers at the thiophene ring. The nitration of 1-methyl-2-(thiophen-3-yl)-1H-benzimidazole involved the thiophene ring or both thiophene and benzene fragments, depending on the conditions. Steric arrangement of the heterocycles in the 1-methyl-2-(thiophen-3-yl)-1H-benzimidazole molecule was analyzed by quantum chemical calculations.

Cytisine and anabasine derivatives containing an acetylenic fragment were used as building blocks in 1,3-dipolar cycloaddition reactions with substituted N-hydroxybenzenecarboximidoyl chlorides, catalyzed by copper(I) salt. The reactions with N-propargylcytisine were not selective, and the products were mixtures of 3,5-disubstituted isoxazoles and small amounts (5–8%) of 3,4-disubstituted isomers. 1,3-Dipolar cycloaddition with N-propargylanabasine afforded 3,5-disubstituted isoxazole derivatives with high regioselectivity.

A general procedure has been proposed for the synthesis of thiazolo[3,2-a]quinazolin-5-one derivatives containing a sulfonamide group on C⁷ via intramolecular nucleophilic substitution of halogen in 2-halo-5-sulfamoyl-N-(1,3-thiazol-2-yl)benzamides. The effects of the degree of activation of the initial compound and halogen nature on the yield of the target products have been analyzed.

Reactions of 2-alkylamino-1,4-naphthoquinones with 2,2-dihydroxy-1H-indene-1,3(2H)-dione afforded 13-alkylbenzo[f]isochromeno[4,3-b]indole-5,7,12(13H)-triones.

N-Sulfinyl-3-(trifluoromethyl)aniline reacted with bicyclo[2.2.1]hept-2-ene and bicyclo[2.2.1]-hepta-2,5-diene to give the corresponding Diels‒Alder adducts which were oxidized to 8-trifluoromethyl-2,3,4,4a,6,10b-hexahydro-5λ⁶-1,4-methanodibenzo[c,e][1,2]thiazine-5,5(1H)-diones. The cycloaddition occurred predominantly with participation of the S=N–C¹=C⁶ fragment of N-sulfinyl-3-(trifluoromethyl)aniline and exclusively at the endo side of bicyclo[2.2.1]heptenes.

Reactions of 3-[(2-bromoprop-2-en-1-yl)sulfanyl]-5H-[1,2,4]triazino[5,6-b]indole with bromine and of 3-[(2-methylprop-2-en-1-yl)sulfanyl]-5H-[1,2,4]triazino[5,6-b]indole with iodine and bromine afforded 3-halomethyl-10H-[1,3]thiazolo[3′,2′: 2,3][1,2,4]triazino[5,6-b]indol-4-ium halides whose structures were determined by ¹H NMR and X-ray analysis.

Directed modification of rctt-tetra-C-naphthyl resorcin[4]arene afforded a heterofunctionalized derivative containing specifically oriented phosphoryl and acetyl groups, and its ability to form complexes with organic amines was studied. The structure and stereochemistry of the resulting complexes depended on the amine nature.

N,N′-Bis(hydroxymethyl)thiourea reacted with propane-1,3-diamine at a molar ratio of 2 : 1 to give 5,5′-propane-1,3-diylbis(1,3,5-triazinane-2-thione), whereas 1,3,5,7,11,13,15,17-octaazatricyclo[15.3.1.1^7,11]-docosane-4,14-dithione was obtained in the reaction with equimolar amounts of the reactants. Tricyclic product was also formed in the three-component condensation of thiourea with formaldehyde and propane-1,3-diamine at a ratio of 1 : 3 : 1. The reactions of N,N′-bis(hydroxymethyl)thiourea with ethane-1,2-diamine (2 : 1) and of thiourea with formaldehyde and butane-1,4-diamine (1 : 2 : 1) afforded 5,5′-(ethane-1,2-diyl)bis(1,3,5-triazinane-2-thione) and 5,5′-(butane-1,4-diyl)bis(1,3,5-triazinane-2-thione), respectively.