Novel (2-amino-4-arylimidazolyl)propanoic acids and pyrrolo[1,2-]imidazoles via the domino reactions of 2-amino-4-arylimidazoles with carbonyl and methylene active compounds.

The unexpectedly uncatalyzed reaction between 2-amino-4-arylimidazoles, aromatic aldehydes and Meldrum's acid has selectively led to the corresponding Knoevenagel-Michael adducts containing a free amino group in the imidazole fragment. The adducts derived from Meldrum's acid have been smoothly converted into 1,7-diaryl-3-amino-6,7-dihydro-5-pyrrolo[1,2-]imidazol-5-ones and 3-(2-amino-4-aryl-1-imidazol-5-yl)-3-arylpropanoic acids. The interaction of 2-amino-4-arylimidazoles with aromatic aldehydes or isatins and acyclic methylene active compounds has led to the formation of pyrrolo[1,2-]imidazole-6-carbonitriles, pyrrolo[1,2-]imidazole-6-carboxylates and spiro[indoline-3,7'-pyrrolo[1,2-]imidazoles], which can be considered as the analogues of both 3,3'-spirooxindole and 2-aminoimidazole marine sponge alkaloids.

Synthesis, structure and affinity of novel 3-alkoxy-1,2-dihydro-3H-1,4-benzodiazepin-2-ones for CNS central and peripheral benzodiazepine receptors.

A series of novel 3-alkoxy-1,2-dihydro-3H-1,4-benzodiazepin-2-ones (7-15) was synthesized and their in vitro affinity for both the central benzodiazepine receptor (CBR) and the peripheral benzodiazepine receptor (PBR) of rat brain was studied. Racemic mixture of 7-bromo-3-(2-methoxy)ethoxy-5-phenyl-1,2-dihydro-3H-1,4-benzodiazepin-2-one (13) was separated into enantiomers 14, 15 by chiral HPLC. Absolute configuration of R-enantiomer 15 was determined by the method of X-ray diffraction analysis.

Synthesis, cytotoxicity, antiviral activity and interferon inducing ability of 6-(2-aminoethyl)-6H-indolo[2,3-b]quinoxalines.

New 6-(2-aminoethyl)-6H-indolo[2,3-b]quinoxalines were synthesized with high yields using bromoethylisatin and 6-(2-bromoethyl)-6H-indolo[2,3-b]quinoxaline as intermediates. These compounds were screened for the cytotoxicity, antiviral activity and interferon inducing ability. It was shown, that tested 6-(2-aminoethyl)-6H-indolo[2,3-b]quinoxalines are low toxic potent interferon inducers and antivirals.

Chiral ureas with two electronegative substituents at 1-N: an unusual case of coexisting pyramidal and almost planar 1-N atoms in the same crystal.

XRD studies of structure of N-acetoxy-N-methoxyurea and N,N-bis(methoxycarbonyl)-N-methoxyimide have revealed that in N-methoxy-N-X-ureas (X = OAc, Cl, OMe, N(+)C(5)H(5)) the additional shortening of N-OMe bond took place, which arising from an n(O(Me))-sigma*(N-X) anomeric orbital interaction. XRD studies of N-chloro-N-ethoxyurea crystal have revealed the presence of two kinds of anomeric nitrogen configuration in the O-N-Cl group in the form of a pyramidal configuration and a planar configuration for same 1-N nitrogen atom. XRD studies of N-4-chlorobenzoyloxy-N-ethoxyurea have revealed that the degree of pyramidality of the 1-N nitrogen in N-aroyloxy-N-alkoxyureas is tuned by orientation of benzoyl group with respect to the N-O bond, which in turn depends of size of N-alkoxy group.

Bis(oxofluorenediyl)oxacyclophanes: synthesis, crystal structure and complexation with paraquat in the gas phase.

The first three representatives of the new family of oxacyclophanes incorporating two 2,7-dioxyfluorenone fragments, connected by [-CH(2)CH(2)O-](m) spacers (m=2-4), have been synthesized. The yield of the smallest oxacyclophane (m=2) is considerably higher with respect to the larger ones (m=3 and m=4), which are formed in comparable yields. Molecular modeling and NMR spectra analysis of the model compounds suggest that an essential difference in oxacyclophanes yields is caused by formation of quasi-cyclic intermediates, which are preorganized for macrocyclization owing to intramolecular pi-pi stacking interactions between the fluorenone units.