Condensed heterocycles containing a thiazole ring. 9. Thiazolotriazinoindoles

Condensation of cyanobenzyl bezenesulfonate with isatin N-dithiocarboxyhydrazones has given representatives of a new heterocyclic system, thiazolo[3',4'2,3]-1,2,4-triazino[5,6-b]indolium, which may be used for the preparation of polymethine dyes.For Communication 8, see [1].Translated from Khimiya Geterosiklicheskikh Soedinenii No. 2, pp. 211–213, February, 1985.     

Condensed heterocycles with a thiazole ring. 1. Thiazolo[3,4-a]pyrimidine derivatives

It is shown that the reaction of 1,3-dicarbonyl compounds or their acetals with 2-methylthio-4-amino-5-phenylthiazolium benzenesulfonate gives 6-methylthiothiazolo[3,4-a]pyrimidinium salts, which react with the appropriate intermediates to give polymethine dyes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 634–638, May, 1982.     

Condensed heterocycles with the thiazole nucleus. 17. Thiazolo[4,3-a]-isoquinolinium compounds

3-Methyl-1-phenylthiazolo[4,3-a]isoquinolinium perchlorate, obtained from -chlorobenzylisoquinoline and thioacetamide, has been used to prepare some symmetrical and unsymmetrical cyanine dyes.For Communication 16, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 553–556, April, 1989.     

Condensed heterocycles containing a thiazole ring. 19. Naphthothiazolopyridinium(quinolinium) salts

It is shown that the salts of condensed naphthothiazoloazines are formed by the interaction of 2,3, dichloro-1,4-naphthoquinone with 2-mercaptopyridine or 2-mercapto-4-R-quinoline.For Communication 18, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1406–1408, October, 1990.     

Condensed heterocycles with a thiazole ring.

Derivatives of new condensed heterocyclic systems — pyrido- and quinolino[1,2:3,2]thiazolo[4,5-b]pyrazines — were synthesized by condensation of 2,3-dichloropyrazine with 2-mercaptopyridine and 2-mercaptoquinolines.See [1] for Communicaton 17.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1276–1278, September, 1990.     

Condensed heterocycles with a thiazole ring. 2. Monomethylidynecyanine dyes of the thiazolo[3,4-a]pyrimidine series

Unsymmetrical monomethylidynecyanine dyes that contain benzothiazole or quinoline residues were obtained on the basis of thiazolopyrimidine. The energies of the transitions and the electron distributions in the ground, first, and second excited states were calculated for several of the dyes obtained and for model compounds by the self-consistent-field configuration-interaction (SCF CI) method in order to interpret the first absorption bands and determine the localization of the electron transitions.See [1] for communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 639–643, May, 1982.     

Condensed heterocycles. 39. Quantum-chemical calculations of the reactivities of some condensed sulfur and selenium heterocycles

A number of isomeric thienothiophenes, selenophenothiophenes, and selenopheno-selenophenes, as well as their C-protonated forms ( complexes), were calculated by the self-consistent-field (SCF) MO LCAO method with the CNDO/2 approximation and the spd basis. Their reactivities in electrophilic substitution reactions were investigated theoretically by means of the localization energy approach. The results were compared with the available experimental data. The dependence of the specificity of electrophilic attack on the size of the attacking reagent was investigated for compounds with various heteroatoms. It is shown that the reactivity of the position relative to the selenium atom should increase as the size of the attacking reagent increases.See [1] for communication 38.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 199–202, February, 1980.     

Condensed heterocycles with a thiazole nucleus. 8. Thiazolo[4,3-a]pyrimido[5,4-e]pyrimidines

Condensation of 4-amino-2-methylthiothiazolium salts with 2,4,6-trichloro-5-formylpyrimidine or 3-R-2,4-dioxo-6-chloro-5-formyl-1,2,3,4-tetrahydropyrimidines yielded mesoionic derivatives of a new heterocyclic system — thiazolo[3,4-a]pyrimido[5,4-e]-pyrimidine — which can be used for the synthesis of polymethine dyes. The absorption maxima of these dyes are bathochromically shifted by 10–20 nm relative to the maxima of the thiazolopyrimidine analogs. The structure of the compounds synthesized was demonstrated by the PMR and IR spectra.For communication 7, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1126–1128, August, 1984.     

Condensed pyrimidine,pyrazine, and pyridine systems.

A simple method was develeped for the synthesis of n₁- and N₃-alkyl- and N₁,N₃-dialkyl(aryl, alkyl)-5-chloroacetyl-6-aminouracil by reaction of 6-aminouracils with chloroacetyl chloride in monochloroacetic acid. 2,4,5-Trioxopyrrole[2,3-d]pyrimidines were obtained by the action of aqueous alkali on N₁alkyl-5-chloroacetyl-6-aminouracils and by the action of sodium ethoxide on N₃-alkyl- and N₁,N₃-dialkyl(aryl, alkyl)-5-chloroacetyl-6-aminouracils. When there is an alkyl substituent attached to the 3-N atom in 2,4,5-trioxopyrrolo[2,3-d]pyrimidines, the pyrrole ring readily opens up under the influence of alkali to give 5-hydroxyacetyl-6-amino uracils.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 537–540, April, 1978.     

Tetrachlorosilane catalyzed multicomponent one-step fusion of biopertinent pyrimidine heterocycles

Multicomponent one-step fusion of a variety of pharmacologically pertinent pyrimidine heterocycles has efficiently been achieved from their respective aldehydes, β-dicarbonyl compounds, and urea/thiourea in the presence of a catalytic amount of tetrachlorosilane in DMF/AN mixture at normal ambient temperature.     

Condensed heterocycles with a thiazole ring. 13. Azinothiazoloquinoxalinium salts

The condensation of 2,3-dichloroquinoxaline with 2-mercaptopyridines and 2-mercaptoquinolines gave the corresponding derivatives of new heterocyclic systems, viz., azino[1,23,2]thaizolo[4,5-b]quinoxalinium salts, which can be used for the synthesis of cyanine dyes.See [1] for Communication 12.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 551–553, April, 1987.     

Steric structure of heterocycles containing phosphorus

¹H and³¹P dynamic NMR, vibrational spectroscopy, and consideration of dipole moments have shown that 2-chloro-2-thiono-4,5;7,8-dibenzo(4,4-dimethyl-6,6-di-tert-butyl)-1, 3,2-dioxaphosphocene and its 2-ethoxy derivative are conformationally heterogeneous. The former exists as a three-component equilibrium mixture, and the latter as a two-component equilibrium mixture. In the chlorothiophosphate the boat-chair conformation predominates, with equatorial location of thiophosphoryl; next in frequency is boat-chair with axial orientation of P=S, and third is the deformed boat form. In the ethyl thiophosphate the preponderant form is the deformed boat with thiophosphoryl in the equatorial position.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2766–2772, December, 1990.     

Synthesis of novel heterocyclic compounds containing pyrimidine nucleus using the Biginelli reaction: Antiproliferative activity and docking studies

In a single reaction step, pyrimidine derivatives ( 4a-p ) were synthesized from the triple reaction of aromatic aldehydes ( 1) , ethyl cyanoacetate ( 2) , and some guanyl hydrazone derivatives (3a-n) . These compounds were tested as in vitro against two types of cancerous cell lines, namely, a human colon cancerous cell line (DLD-1) and a human breast cancerous cell line (MDA-MB-231). According to the obtained results, nearly all the compounds have cytotoxic activity in the tested cell lines. Especially, the compounds 4j , 4k , and 4n had a significant effect against DLD-1. Furthermore, compounds 4g , 4m , and 4o exhibited lower IC₅₀ values compared to other synthesized compounds against MDA-MB-231. We hope that these compounds can be improved as anticancer agents in the future. Molecular docking was performed according to both topoisomerase I and N-acetyltransferase 1 proteins to examine theoretically the binding mode and site of pyrimidine compounds having the best activity.     

The aromaticity of heterocycles containing the imine nitrogen

The method of predicting aromaticity based on simple Hückel calculations is applied to heterocyclic systems which contain the imine nitrogen. The necessary heteroatom integrals were determined from thermochemical data. Replacement of C by N in alternant systems produced no dramatic changes, but in nonalternants the effect can be large and unexpected as in the azapentalenes where interesting synthetic possibilities are suggested.     

Macrocyclic compounds containing three pyrimidine fragments

The reactions of disodium salts of N,N"-bis(2-mercapto-6-methylpyrimidin-4-yl)alkylenediamines with 1,3-bis(-bromoalkyl)-6-methyluracils afforded a series of macrocyclic compounds containing three pyrimidine fragments with different numbers of methylene groups in linking bridges.     

Synthesis and antitumor activity of some nitrogen heterocycles bearing pyrimidine moiety

Synthesis of novel pyrimidine derivatives 4-16 was accomplished by heterocyclization of polarized system, for example, Chalcone. Claisen-Schmidt condensation of 2-acetyl naphthalene with 4-(N, N-dimethylaminobenzaldehyde) afforded chalcone 3 , which was utilized for synthesis various pyrimidine derivatives by treatment with urea, thiourea, and guandine hydrochloride in ethanolic sodium hydroxide solution. The reactivity of the synthesized pyrimidine derivatives towards different nucleophilic and electrophilic reagent were examined. The constructions of the newly synthesized pyrimidine derivatives were elucidated from their spectral and elemental analysis. All the synthesized compounds were tested in vitro for their anticancer activities against HePG-2 and MCF-7 cell lines. Some of them posses a wide range of pharmacological activity. Finally, a molecular docking study was conducted to reveal the probable interaction with the dihydrofolate reductase (DHFR) active site.     

Quaternary salts of some heterocycles containing nitrogen

A series of mono- and biquaternary salts were synthesized from 1, 3-dichloropropane-2-ol and the nitrogen-containing heterocycles quinoline, isoquinoline, quinaldine, pyridine, 2-picoline, and lepidine. The UV-spectra of the compounds obtained were investigated.