Synthesis and some conversions of N-substituted benzimidazole-2-sulfonic acids

A series of N-substituted benzimidazole-2-sulfonic acids was synthesized in good yield by the N-alkylation of benzimidazole-2-sulfonic acids by alkylation with simple and functionalized alkylating agents under mild conditions. The corresponding N-substituted benzimidazolones and also primary, secondary, and tertiary amines were obtained by the action on the obtained compounds of alkali, ammonia, ammonium acetate, and amines. __________ Translated from Khimiya Geterotsiklicheskikh, No. 4, pp. 528–534.     

Synthesis of 4(5)-hydroxymethylimidazoles by hydroxymethylation and decarboxylation of imidazole-4(5)-carboxylic acids

4(5)-Hydroxymethylimidazoles were prepared by hydroxymethylation and decarboxylation of imidazole-4(5)-carboxylic acid esters. The reaction was simply carried out with aqueous formaldehyde solution in the presence of base.     

Synthesis and In vitro biological activity of some 7-(5-aminomethyl-2-isoxazolidinyl)quinolone-3-carboxylic acids

The synthesis of the title compounds via nitrone cycloaddition is described. The in vitro antibacterial activity of these compounds is compared against 1-ethyl-6,8-difluoro-7-[3-[(ethylamino)methyl]-1-pyrrolidinyl]-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (CI-934).     

Synthesis of methyl esters of 6-dialkylamino-2-(carbethoxy)-methylthiopyrimidine-4-carboxylic acids

A preparative method is proposed for the synthesis of methylesters of 6-dialkylamino-2-(carbethoxy)methylthiopyrimidine-4-carboxylic acids form the butyl ester of orotic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 818–821, June, 1986.     

Synthesis of methyl esters of 5-aroyl-6-aryl-2-oxo-1,2,3,6-tetra-hydropyrimidine-4-carboxylic acids

Methyl esters of 5-aroyl-6-aryl-2-oxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acids were synthesized from three component mixtures of methyl esters of aroylpyruvic acids, urea, and substituted benzaldehydes. 8-Hydroxy-4,5-diphenyl-3,4-dihydropyrimido[4,5-d]pyridazin-2(1H)-one was synthesized by the reaction of 5-benzoyl-2-oxo-6-phenyl-1,2,3,6-tetrahydropyrimidin-4-carboxylate with hydrazine hydrate.     

Synthesis and exchange reactions of 5-alkyl-2-oxo-6-thioxo-1,2,3,6-hexahydropyrimidine-4-carboxylic acids

An improved preparation of 2-oxo-6-thioxo-1,2,3,6-hexahydropyrimidine-4-carboxylic acid 3, a potent inhibitor of dihydroorotase is presented. Trans-5-alkyl-2-oxo-6-thioxohexahydropyrimidine-4-carboxylic acids 12a-c were synthesised via the thiation of the p-methoxybenzyl esters of 5-alkyldihydroorotic acids with Lawesson's reagent followed by subsequent de-protection. The corresponding cisisomers were prepared by reduction of 5-alkyl-6-thioxoorotic acids with zinc in acetic acid. The stability and exchange reactions of 12a-c under physiological conditions were investigated by ultra-violet and ¹H nmr spectroscopy. The attempted synthesis of 16 , a fused cyclopentyl derivative of 3 is also presented.     

Synthesis of 1-aryl-5-(trifluoromethyl)-1H-pyrazole-4-carboxylic acids and esters

Ethyl 1-aryl-5-(trifluoromethyl)-1H-pyrazole-4-carboxylates 2 were prepared by the condensation of arylhydrazines with ethyl 3-ethoxy-2-(trifluoroacetyl)-2-propenoate (1a) at low temperature. The corresponding acids were also synthesized. X-ray diffraction analysis of an amide derivative 4 verified the position of the trifluoromethyl group on the pyrazole ring.     

Synthesis and reactions of some 5(6)-(1-adamantyl)benzimidazoles

4-(1-Adamantyl)-1,2-diaminobenzene, previously unreported in the literature, has been prepared and a novel series of 5(6)-(1-adamantyl)benzimidazole derivatives synthesized. Nitration, hydrogenation, and side chain reactions have been carried out. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1172–1182, August, 2008.     

Synthesis and transformations of polysubstituted diastereomeric 5-oxomorpholin-2-carboxylic acids

A series of trans- and cis-3,4-disubstituted 5-oxomorpholine-2-carboxylic acids 5 were prepared by a cyclocondensation between diglycolic anhydride 3 and arylideneamines 4. Transformations of the carboxylic group leading to a peptide bond in the side chain to the morpholinone ring were effected. The relative configurations and the preferred conformations of the substituents at the morpholinone ring in some of the newly prepared derivatives were determined by means of ¹H NMR and X-ray analysis.     

Synthesis of some bifunctional derivatives of 8-methylquinoline-5-carboxylic acid

Derivatives of 8-methylquinoline-5-carboxylic acid were synthesized. Alcoholysis of 8-methyl-5-cyanoquinoline gave methyl and ethyl 8-methylquinoline-5-carboxylates, which were converted to the corresponding 8-bromomethyl derivatives. The latter were used for the introduction of a methylamino group and the synthesis of N-acyl derivatives. The hydrazide, amide, and anilide of 8-methylquinoline-5-carboxylic acid were obtained as model compounds.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 785–788, June, 1982.     

Synthesis of benzimidazole-2-carboxylic acid amides from o-phenylenediamine and oxamic acid esters

A method for the preparation of N-R amides of benzimidazole-2-carboxylic acid on the basis of the reaction between o-phenylenediamine and esters of N-R oxamic acids was developed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 684–686, May, 1982.     

Conversion of amino hydroxyacids to oxazolidine-4-carboxylic acids,oxazolidine-5-carboxylic acids and tetrahydrooxazine-4-carboxylic acids

The title compounds are stable in aqueous solution above pH 7, and can be isolated following N-acylation.     

Synthesis and antibacterial activity of new 5-substituted 1-cyclopropyl-6-fluoro-7-piperazinyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acids

The 5-hydroxymethyl and the 5-formyl-1-cyclopropyl-6-fluoro-7-piperazinyl-1,4-dihydro-4-oxo-1,8-naphthyridine-3-carboxylic acids have been prepared via a 5-trimethylsilyl group and were tested in vitro as potential antibacterials.     

Synthesis of esters of metallocene alcohols and 4,5-dichloroisothiazol-3-carboxylic and 5-arylisoxazole-3-carboxylic acids

Acylation of alkyl- and 1,1′-dialkylferrocene alcohols and diols as well as (3,4,4-trichlorobut-3-ene-1-ol-1-yl)-4,5-cymantrene with dichloroisothiazole- and 5-arylisoxazole-3-carbonyl chlorides has afforded esters containing 1,2-azoles fragments. Some of the obtained compounds have exhibited potentiating action in the binary mixtures with insecticides.