Synthesis and Structural Characterization of the 5-(2- Haloethyl)pyrimidines - Hydrogen-Bonded chains in a-(1- Carbamyliminomethylene)-g-Butyrolactone

Three novel 5-(2-haloethyl)pyrimidine derivatives were synthesized and characterized by 1H-NMR, 13C-NMR, MS, IR spectra and elemental analysis. Iodine and chlorine atoms in the C-5 side chain were introduced by reaction of 5-(2- hydroxyethyl)pyrimidine with hydroiodic acid and phosphoryl chloride, respectively. The structure of the intermediate a-(1-carbamyliminomethylene)-g-butyrolactone was determined by X-ray crystal structure analysis. The molecule deviates very slightly from planarity. Three NHO hydrogen bonds link the molecules into one-dimensional chains of edge-fused rings

Merocyanine Isomers of Spiro[indolino-indolopyrans]: 1H and 13C NMRand X-ray Crystal Structure Study

The synthesis of stable merocyanine isomers 4 and 5 of the corresponding spiro[indolino-indolopyrans] is described. The structure of 4 and 5 was deduced on the basis of their lH and 13C NMR spectra. Geometrical data from X-ray structure analysis show that indolo and indolino rings in 4 are coplanar with the central diene bridge. The bond length shortening of the central single bond and the heterocyclic moieties indicate an electron delocalization over the whole molecule

New Acyclic Purine Nucleoside Analogues Containing Exocyclic Pyrrolo Moiety: Synthetic, NMR and X-ray Crystal Structure Studies

The synthesis of novel 6-(N-pyrrolyl)purine nucleoside analogues containing acyclic side chains attached to the purine ring at N-9 is described. The structures were determined by 1H and 13CNMR on the basis of chemical shifts, substituent induced shifts, C-H coupling constants and connectivity in the COSY,NOESY and HETCOR spectra. Unequivocal proof for the stereostructure of 6 was obtained by its X-ray crystallographic analysis. Geometrical data from X-ray structural analysis showed that the two 6-(N-pyrrolyl) purine rings involved in the skeleton of 6 are anti-disposed but not centrosymmetric with respect to the central aliphatic bridge

Merocyanine Isomers of Spiro[indolino-indolopyrans]: 1H and 13C NMRand X-ray Crystal Structure Study

The synthesis of stable merocyanine isomers 4 and 5 of the corresponding spiro[indolino-indolopyrans] is described. The structure of 4 and 5 was deduced on the basis of their lH and 13C NMR spectra. Geometrical data from X-ray structure analysis show that indolo and indolino rings in 4 are coplanar with the central diene bridge. The bond length shortening of the central single bond and the heterocyclic moieties indicate an electron delocalization over the whole molecule

New Acyclic Purine Nucleoside Analogues Containing Exocyclic Pyrrolo Moiety: Synthetic, NMR and X-ray Crystal Structure Studies

The synthesis of novel 6-(N-pyrrolyl)purine nucleoside analogues containing acyclic side chains attached to the purine ring at N-9 is described. The structures were determined by 1H and 13CNMR on the basis of chemical shifts, substituent induced shifts, C-H coupling constants and connectivity in the COSY,NOESY and HETCOR spectra. Unequivocal proof for the stereostructure of 6 was obtained by its X-ray crystallographic analysis. Geometrical data from X-ray structural analysis showed that the two 6-(N-pyrrolyl) purine rings involved in the skeleton of 6 are anti-disposed but not centrosymmetric with respect to the central aliphatic bridge