Structural Studies on Selected Drug Intermediates Some of Their Multi Component Systems and Schiff Bases

Abstract

The present thesis discusses the Structural studies on selected drug intermediates, newlinesome of their multi component systems and schiff bases. For three dimensional structure newlinedetermination, single crystal x-ray diffraction method had been used. For spectral studies, newlineUV, FT-IR, FT-Raman, 1H, 13C NMR techniques had been exploited. For comparison of newlineexperimental results with the theoretical ones, DFT calculations had been done. Hirshfeld newlinesurface analysis had been utilised to know the contribution of percentage of inter atomic newlineinteractions to the overall packing of the crystals. newlineIn the investigation of the crystal structures of 3-(4-Chloro-butyl)-1H-Indole-5- newlinecarbonitrile (CBCl), 5-Bromo-3-(N-methyl-pyrrolidine-2-ylmethyl)-1H-indole (IBrMP) newlineand 2-(1H-Indole-5-yl)-N-methylethane sulfonamide (ISA), their preferred hydrogen newlinebonding patterns were discussed. In the crystal structures, crystal engineering involves the newlinestrong N-H O, N-H N, O-H O, O-H N, water mediated Ow-Hw O and inter and newlineintra molecular O-H O hydrogen bonds and the weak intermolecular C-H N/O and CH Cl hydrogen bonds. The variety of aromatic and#960; and#960; stacking interactions, newlinehalogen...halogen interaction and halogen and#960; interaction had also been discussed. A newlinedetailed experimental interpretation of FT-IR, FT-Raman, 1H NMR, 13C NMR and UV newlinespectral values were given in comparison with the theoretically calculated values. The newlineHirshfeld surface analysis had indicated the percentage of intermolecular interaction of newlineneighbouring atoms for each of the three parent compounds. newlineIn the crystal structures of 4-pyridin-4-yl-3H-1,3-thiazole-2-thione (PTT) (I), 4- newlinepyridin-4-yl-3H-1,3-thiazole-2-thione maleic acid (PTTMA) (II) and 4-pyridin-1-ium-4- newlineyl-3H-1,3-thiazole-2-thione perchlorate monohydrate (PTTPH) (III), the supramolecular newlinearchitecture and its various interactions governed by strong N-H O, O-H N and OH O, weak C-H N/O and stacking/non-covalent interactions were analysed with a newlineview to getting more information about the supramolecular patterns.