Synthesis of some new pyrimidine selanyl derivatives

The targeted synthesis of 2-(methylsulfanyl)-6-(furan-2-yl)-4(3H)-selenoxo -pyrimidine-5-carbonitrile failed due to the formation 1-methyl-2-methylsulfanyl-6-oxo -4-(furan-2-yl)-1,6-dihydropyrimidine-5-carbonitrile. A new series of 5,6,7,8-tetrahydro-1-benzo thieno[2,3-d]pyrimidine-4-yl substituted selanyl derivatives were prepared by the reaction of sodium diselenide with 4-chloro-5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidine followed by the reaction with chloroacetic acid derivatives such as ethyl chloroacetate, chloroacetamide or chloroacetonitrile. Hydrazinolysis of ethyl (5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidine- 4-ylselanyl)acetate with hydrazine hydrate gave the corresponding hydrazino derivative. The latter reacted with ethyl acetoacetate, acetylacetone, diethyl malonate, ethoxymethylenemalononitrile or ethyl 2-cyano-3-ethoxyacetate to afford 5-methyl-2-[2-(5,6,7,8-tetrahydro-1-benzothieno [2,3-d]pyrimidine-4-ylselanyl)acetyl]-2,4-dihydropyrazol-3-one, 1-(3,5-dimethylpyrazol-1-yl)-2- (5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-ylselanyl)ethanone, 1-[2-(5,6,7,8-tetrahydro -1-benzothieno[2,3-d]pyrimidine-4-ylselanyl)acetyl]-2,4-dihydropyrazolidine-3,5-dione and 5-Amino-1-[2-(5,6,7,8-tetrahydro-1-benzothieno[2,3-d]pyrimidin-4-ylselanyl)acetyl]-1H-pyrazol -4-yl substituted carbonitrile or ethyl carboxylate, respectively. The structure of the novel compounds was confirmed by spectroscopic tools (IR, ¹H NMR ¹³C NMR and mass spectra) and elemental analysis.     

Synthesis and properties of some pyrimido[5,4-d]pyrimidine derivatives

A method for the preparation of 2,4,8-trioxo-6-methyl derivatives of pyrimido[5,4-d]pyrimidine with various alkyl residues in the 7 position is described. It is shown that the chlorine in the 4 position of the 2,4-dichloro derivative of pyrimido[5,4-d]pyrimidine is the most labile in nucleophilic substitution reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 517–520, April, 1977.     

Synthesis and transformations of pyrimidine derivatives

A methoxyl group in the 4 and 6 positions has a passivating effect on the ability of the methyl group in monomethoxymethylpyrimidine derivatives to enter into azo coupling; at the same time, a methoxyl group in the 2 position does not have an appreciable effect on the activity of the methyl group because the conjugation effect of the methoxyl group in this position is less than in the 4 and 6 positions.See [1] for Communication XVIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1573–1574, November, 1970.     

Synthesis of some new pyrimidine derivatives and evaluation of their anticancer and antibacterial activities

Starting from the reaction of ethyl cyanoacetate with thiourea and the appropriate aldehydes, a series of new pyrimidine derivatives were prepared. Ten selected pyrimidine derivatives were subjected to a screening system for the investigation of their antitumor potency against liver (HEPG2) cell line. The antitumor activity results indicated that most of the selected pyrimidine derivatives showed moderate growth inhibition activity against the tested cell line, but with varying intensities in comparison to the known anticancer drugs: 5-fluorouracil and doxorubicin. Some of the synthesized compounds were also tested for their antimicrobial activity against bacteria as well as fungal isolates.     

Structure and dynamics of some macrocyclic pyrimidine derivatives

The conformation of macrocycles consisting of the uracil and two thiopyrimidine moieties linked by polymethylene spacers depends on the spacer length, intramolecular hydrogen bonds, and the solvent nature. In CDCl₃ the intramolecular hydrogen bond (NH) appreciably stabilizes the “skew” conformation but only for the macrocycles with methylene spacers consisting of five carbon atoms. Protonation leads to the cleavage of intramolecular hydrogen bonds, destabilization of the “skew” conformation, and self-association due to the strong intermolecular hydrogen bond involving the acid counterion, and the intermolecular bond is cleaved in a polar solvent.     

Synthesis,characterization, antioxidant properties and DFT calculation of some new pyrimidine derivatives

Abstract

In this study, 5-benzoyl-4-(4-(methylthio)phenyl)-6-phenyl-1,2,3,4-tetrahydro-2-thioxo (1), oxo (2) and imino (3) pyrimidine derivatives were prepared via Multicomponent Cyclocondensation Reactions (MCRs). The compounds thiazolo[3,2-a]pyrimidin-3(5H)-one (4) and thiazin-4(6H)-one (5) were obtained via the reaction of compound 1 with bromoacetic acid and 3-bromopropionic acid, respectively. Structures were determined by using FT-IR, ¹H/¹³C NMR and elemental analyses. Also the compounds 4 and 5 were analyzed by X-ray single crystal analysis. All compounds were investigated as corrosion inhibitors using density functional theory (DFT) at the level of B3LYP/6-31G (d, p). According to the calculations, the compound 3 appears to be a good inhibitor for corrosion. On the other hand, total antioxidant properties were measured in vitro by DPPH^?, ABTS^?+ test, hemolysis of phenylhydrazine erythrocytes and metal chelating effect. The results were compared with standard antioxidants such as trolox and α-tocopherol. These data revealed that compounds 1, 2 and 5 are more active with respect to 3 and 4 in scavenging the radicals.     

Synthesis and antibacterial activity of some imidazo[1,2-a]pyrimidine derivatives.

A series of 75 imidazo[1,2-a]pyrimidine derivatives were synthesized. The "in vitro" antibacterial activity of these compounds and their corresponding alpha-bromoketones against a variety of gram (+), gram (-) bacteria and Mycobacterium species is reported. Some of the prepared derivatives exhibited potent antimicrobial activity.     

Synthesis of isochroman-fused pyrazolone and pyrimidine derivatives

Unsubstituted 5 , and 2-aryl- 6a-c , or 2-(2-benzothiazolyl)-substituted 1,3-dihydroisochromano[4,3-c]pyrazol-3(2H)-ones 7a-f were prepared by the reactions of 3-ethoxyoxalyl- 2 , or 3-ethoxycarbonylisochroman-4-one 3 with hydrazine derivatives. The reactions with amidines gave 2-substituted 4-hydroxyisochromano[4,3-d]-pyrimidines 8a-c .     

Synthesis of some polycyclic noncondensed pyrimidine structures

Methods for the synthesis of compounds containing two or more pyrimidine rings linked through aliphatic chains with different numbers of carbon atoms are described.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 335–340, February, 1995     

Synthesis of bicyclic pyrimidine derivatives as ATP analogues

A highly efficient and general solid-phase synthesis of bicyclic pyrimidine derivatives that target purine dependent proteins is reported. The synthesis of the key intermediate, 4,6-disubstituted-5-amino-pyrimidine, involved reduction of the corresponding nitro derivatives using 1,1'-dioctyl-viologen in a triphasic milieu. The mild reduction conditions enable the use of any acid labile solid support as well as a wide range of combinatorial substituents, thus enabling the synthesis of large libraries of highly diverse bicyclic pyrimidines. Alternative reduction conditions with tin(II) chloride and structure-reactivity studies are discussed as well.     

Synthesis of imidazo[1,5-c]pyrimidine derivatives

Two complementary procedures, each starting from 6-aminomethyluracil ( 2 ), have been used to prepare imidazo[1,5-c]pyrimidines with a variety of substituents at positions 3, 5, 6, and 7. The starting material, 2 , can be readily prepared from commercially available 6-chloromethyluracil by reaction with anhydrous ammonia. In the first procedure, 2 is acylated and then cyclodehydrated by reaction with phosphorus oxychloride to give a separable mixture of a 3-substituted 5,7-dichloroimidazo[1,5-c]pyrimidine and a 3-substituted 7-chloroimidazo[1,5-c]pyrimidin-5(6H)-one. The relative product distribution is subject to some control by the choice of the acyl substituent on the starting uracil. The resulting dichloro compounds were derivatized by reaction at the 5-position with various nucleophiles, although the 7-chloro substituent is unreactive. An alternative synthetic method proceeds from 2 in six efficient steps (protection as the phthalimide, chlorination, nucleophilic substitution, deprotection, acylation, and cyclodehydration) to 3-substituted-5,7-bis(methylthio)imidazo[1,5-c]pyrimidines. These compounds may also be derivatized by nucleophilic substitution at the 5-position.     

Synthesis of some phenanthridone derivatives

The alkylation of phenanthridone and some nuclear-substituted phenanthridones using sodium hydride in DMF/benzene is reported. Various 5-cyanoalkylphenanthridones were converted to further derivatives by either hydrolysis or reduction.     

Synthesis of some thiophene derivatives

The synthesis of thiopene derivatives from diacetylenic hydrocarbons has been described [1]. We have examined for the first time the reaction of diacetylenic diesters with hydrogen sulfide and with NaHS. The diacetylenic diesters react readily with hydrogen sulfide or NaHS in acetone at pH 9–10 to give 2,5-disubstituted thiopheries (see Table 1).Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 5, pp. 713–714, May, 1970.     

Synthesis of some sym-triazole derivatives

3,5-Di(hydroxyalkyl) derivatives of 4-amino-1,2,4-triazole and the corresponding derivatives of 1,2,4-triazole obtained by diazotizing them are converted by reaction with SOCl₂ into the hydrochlorides of 4-amino-3,5-di(chloroalkyl)-1,2,4-triazoles and 3,5-di(chloroalkyl)-1, 2,4-triazoles. The dinitrate of 3,5-di(hydroxymethyl)-1,2,4-triazole has been prepared. When the cyanohydrazide of glycolic acid is heated with hydrazine hydrate, 4,5-diamino-3-hydroxymethyl-1, 2,4-triazole is formed.     

Synthesis of pyrrolo[1,2-a]pyrimidine derivatives

8-Cyanopyrrolo[1,2-a]pyrimidines, the cyano group of which is eliminated when they are heated with phosphoric acid, were obtained by reaction of 2-amino-3-cyanopyrroles with acetylacetone.Compounds Ia, c-g were described earlier in [3], while Ib, h are described in the present work.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1677–1681, December, 1976.     

Synthesis of some thienopyrimidine derivatives

Thioxothienopyrimidinones, alkylthio- and arylalkylthiothienopyrimidinones, thienopyrimidinones, thienopyrimidines a thienopyrimidinedione and a thienotriazolo-pyrimidinone were prepared from 2-amino-3-carboethoxy-4,5-disubstituted thiophenes and 2-amino-3-cyano-4,5-disubstituted thiophenes via reactions with different reagents.