Band 18, Heft 5-6

The S N Ar and Pd-catalyzed amination of chloro derivatives of azines, diazines, and triazines with 2-aminopyridine 1-oxides and their N -protected derivatives was described.

A new efficient method of synthesizing 3-cyano-pyridine-2(1 H )-ones containing variable substituents at position 4 and various aromatic substituents at position 1 of the pyridinone ring has been developed. The method is based on the reaction of ylidenecyanoacetic acid ethyl esters with dimethylformamide dimethyl acetal, the re-amination of obtained derivatives with several aromatic amines in glacial acetic acid and the final cyclization of the intermediate products to targeted N-aryl-3-cyano-pyridine-2(1 H )-ones. The condensation reactions of some of the synthesized compounds with several aldehydes have been investigated.

New 3-chalcone-substituted 1,4-dihydropyridine (DHP) derivatives have been synthesized based on dimethyl or diethyl 2,6-dimethyl-4-phenyl-1,4-DHP-3,5-dicarboxylate. Their structures were confirmed by IR, 1 H NMR, 13 C NMR, and elemental analyses. The synthesized compounds were also screened for antioxidant properties.

A simple, inexpensive and efficient one-pot synthesis of piperidine derivatives was achieved in excellent yield via the three-component reaction of substituted aniline, 1,3-dicarbonyl compound and aromatic aldehyde using phenylboronic acid as catalyst.

Scandium triflate efficiently promotes a one-pot, three-component condensation of aldehydes, malononitrile, and thiophenols to produce highly substituted pyridines in good yields. This reaction does not involve any hazardous organic solvent and toxic catalyst.

Condensation of Gewald’s thiophenes substituted with a dimethylaminomethyleneamino group at position 2 with primary amines yields 5/6-aryl-thieno[2,3- d ]pyrimidin-4-ones with variable substituents at the N3 position.

A rapid and efficient method for the preparation of new pyrido[2,3- d ]pyrimidinone derivatives by the condensation of 2-amino-4-aryl-6-arylnicotinamides with carbon disulfide or cycloalkanones under focused microwave irradiation is described.

New N -substituted 2-imino-2,5-dihydrofurans were synthesized by using several efficient approaches starting from readily available 2-imino-2,5-dihydrofurans. All new compounds were characterized by NMR and IR spectral data and elemental analysis.

Photochemical oxidation of substituted coumarins 1 , 3 and 5 in benzene solution containing iodine gave the respective products 2 , 4 and 6 . The structures of the photoproducts have been confirmed by analyses of analytical and spectral data. The experimental results are further strengthened by their agreement with computationally calculated dipole moments (μ), minimum-energy values and heats of formations.

Five aminoalkyl 1 H -benzo[ de ]isoquinoline-1,3(2 H )-diones were synthesized and evaluated for antimicrobial activity. Microorganisms used in this study included aerobic and facultative anaerobic bacteria Staphylococcus aureus , Escherichia coli and Stenotrophomonas maltophilia , and obligatory anaerobes Bacteroides fragilis , Bacteroides thetaiotaomicron and Propionibacterium acnes . Moreover, Candida albicans yeast was used. The minimum inhibitory concentration (MIC) was determined for the test compounds. Among the tested derivatives, two compounds 1 and 2 have shown the most potent antibacterial as well as antifungal activities.