Nabila A. Kheder

Facile and Convenient Synthesis of New Thieno[2,3-b]-Thiophene Derivatives

A facile and convenient synthesis of bis(2-(1H-benzo[d]imidazol-2(3H)-ylidene)-3-oxopropanenitrile), bis((3-amino-5-(methylthio)-1H-pyrazol-4-yl)methanone) and bis(2-thioxo-1,2-dihydropyrimidine-5-carbonitrile) derivatives incorporating a thieno- [2,3-b]thiophene moiety via versatile, readily accessible diethyl 3,4-dimethylthieno-[2,3-b]thiophene-2,5-dicarboxylate (1) is described.

SYNTHESIS AND ANTIMICROBIAL EVALUATION OF NEW PYRAZOLE, THIOPHENE, THIAZOLE AND 1,3,4-THIADIAZOLE DERIVATIVES INCORPORATING PYRIMIDINE RING

The utility of 3-oxo-N-(pyrimidin-2-yl)butanamide (1) in the synthesis of some new pyrazole, thiophene, thiazole, and 1,3,4-thiadiazole derivatives pendant to a pyrimidine ring is reported. Antimicrobial evaluation of some selected examples from the synthesized products was carried out and showed moderate activity.

Facile and Convenient Synthesis of Pyrazole, Pyridine, Pyridazine, Pyrazolo[3,4-b]pyridine, and Pyrazolo[5,1-c][1,2,4]triazine Derivatives

Abstract A convenient synthesis of a series of pyrazole, pyridine, pyridinethione, pyridazine, pyrazolo[3,4-b]pyridine, imidazo[1,2-a]pyrimidine, and pyrazolo[5,1-c][1 2 4]triazine derivatives incorporating a pyrimidine moiety, via the reactions of the versatile, readily accessible 3-oxo-N-(pyrimid-2-yl)butanamide with the appropriate reagents, is described.

SYNTHESIS AND ANTIMICROBIAL EVALUATION OF SOME NEW PYRIMIDINE DERIVATIVES

The utility of ethyl 6-methyl-2-oxo-4-phenyl-1,2-dihydropyrimidine-5-carboxylate (1) in the synthesis of some new pyrido[1,2-f]pyrimidine, pyrazolo-[3,4-b]pyrido[1,2-/]pyrimidine, 6-(4-substituted styryl)pyrimidine, pyrido[4,3-d]-pyrimidine, pynmido[5,4-d]pyridazine and substituted-6-(thien-2-yl)pyrimidine derivatives is reported. Antimicrobial evaluation of some selected examples from the synthesized products was carried out.

Synthesis and Antimicrobial Studies of Some Novel Bis-(1,3,4)thiadiazole and Bis-thiazole Pendant to Thieno(2,3-b)thiophene Moiety

The synthetic utility of 3,3′-(3,4-dimethylthieno[2,3-b]thiophene-2,5-diyl)bis (3-oxopropanenitrile) (1) in the synthesis of some novel bis-[1,3,4-thiadiazole] 6a–g and bis-thiazole 10 and 13 derivatives with thieno[2,3-b]thiophene moiety is reported. Antimicrobial evaluation of some selected examples from the synthesized products was carried out and showed promising results.

One Pot Single Step Synthesis and Biological Evaluation of Some Novel Bis(1,3,4-thiadiazole) Derivatives as Potential Cytotoxic Agents

A novel series of bis(1,3,4-thiadiazole) derivatives were synthesized in one step methodology with good yields by condensation reaction between bis-hydrazonoyl chloride 1 and various reagents. The structures of the prepared compounds were confirmed by spectral data (IR, NMR, and MS), and elemental analysis. The anticancer activity against human breast carcinoma (MCF-7) cancer cell lines was evaluated in MTT assay. The results revealed that the bis-thiadiazole derivatives 5c,d, 7b,c and 9c had higher antitumor activity than the standard drug Imatinib.

SYNTHESIS AND ANTIMICROBIAL EVALUATION OF SOME NEW PYRIDINE BASED HETEROCYCLES

A facile and convenient synthesis of pyridine, pyridazine, 2(3H)-1,3,4-thiadiazole and pyrazole derivatives incorporating a pyridine-2-ylcarboxamido moiety via the versatile, readily accessible 3-oxo-N-(pyridin2-yl)butanamide is described. Antimicrobial evaluation of some selected examples from the synthesized products was carried out and showed moderate activity.

Regioselective synthesis of polysubstituted 3,3′-bi-1H-pyrazole derivatives via 1,3-dipolar cycloaddition reactions

Abstract N,N′-Diarylbisnitrile imides 2 add regioselectively to α-(benzothiazol-2-yl)cinnamonitriles 3 and α-(1-methylbenzimidazol-2-yl)cinnamonitriles 7 to yield exclusively the cycloadducts 5,5′-dicyano-4,4′,5,5′-tetrahydro[3,3′-bi-1H-pyrazoles] 4 and 8, respectively. Compounds 4 and 8 undergo aromatization via thermal elimination of hydrogen cyanide under basic conditions to afford the corresponding 3,3′-bi-1H-pyrazole derivatives 6 and 10, respectively. The regiochemistry of the cycloadducts is discussed.

A convenient route to new pyrrolo〔1,2-c〕pyrimidone, thiazolo〔3,4-c〕pyrimidone and pyrimido〔4,5-d〕pyridazine derivatives

The utility of versatile, readily accessible ethyl 6-bromomethyl-2-oxo-4-phenyl-l,2,3,4-tetrahydropyrimidine-5-carboxylate (3) and ethyl 6-bromomethyl-2-oxo-4-phenyl-1,2-dihydropyrimidine-5-carboxylate (4) in the synthesis of some new pyrimidine, pyrimido[4,5-d]pyridazine, pyrrolo[1,2-c]pyrimidone and thiazolo[3,4-c]pyrimidone derivatives is reported.

Synthesis and antimicrobial evaluation of some new tetrahydropyrimidine derivatives

The utility of 1,2,3,4-tetrahydropyrimidine-5-carboxylate (1a,b), and 1,2-dihydropyrimidine-5-carboxylate (2) in the synthesis of some new functionalized pyrimidine derivatives such as 6-(2-(dimethylamino)vinyl)-1,2,3,4tetrahydropyrimidine, 6-(1-cyano-2-(phenylamino)-2-thioxoethyl)-1,2,3,4-tetrahydropyrimidine and 4,6-distyryl-1,2-dihydropyrimidine derivatives is reported. Antimicrobial evaluation of some selected examples from the synthesized products was carried out and showed promising results. Pyrimidine derivatives are reported to possess antibacterial, antifungal anticancer, antiinflammatory, and cardioprotective effects. In addition, certain pyrimidine derivatives are known to display antimalarial, antifilarial and antileshmainal activities. Also, pyrimidine nucleus is considered as one of the most important classes of chemotherapeutic drugs. Many pyrimidine derivatives are used for thyroid drugs and leukemia. In view of the these results and as an extension of our recent work concerned with the synthesis of heterocycles of interested biological activity we decided to synthesize some new pyrimidine derivatives starting from the readily obtainable 1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives 1a, 1b, and dihydropyrimidine 2 as highly versatile and useful building blocks for the synthesis of a wide variety of pyrimidine derivatives and to test their antimicrobial activity. 1,2,3,4-Tetrahydropyrimidine 1a was found to react readily with dimethylformamide dimethyl acetal (DMF-DMA) to produce ethyl 6-(2-(dimethylamino)vinyl)-2-oxo-4-phenyl-1,2,3,4-tetrahydropyrimidine5-carboxylate (3) (Scheme 1). The IR spectrum of the product 3 showed absorption bands at, 1624, 1701, 3117, 3244 cm due to two carbonyl groups, and two imino functions, respectively. Its H NMR spectrum showed a triplet signal at  1.11 (J = 6.9 Hz) due to CH3 protons, singlet signal at  2.85, characteristics for two methyl protons, a quartet signal at  3.96 (J = 6.9 Hz) due to CH2 protons, a doublet signal at  5.17 (J = 3.6 Hz) due to CH proton, two doublets at  6.18 and  7.48 (J = 14.1 Hz) due to two olefinic protons, and two D2O-exchangeable signals at  7.52 and 8.61 corresponding to two NH protons, in addition to an aromatic multiplet in the region  7.22-7.29. The value of the coupling constant for the ethylenic protons indicates that the pyrimidine 3 exists exclusively in the E-configuration.