http://nopr.niscair.res.in/handle/123456789/6095 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/6118 Title: Cu(OTf)₂-catalyzed <i style=""><img src='/image/spc_char/alpha.gif'></i>-halogenation of ketones with 1,3-dichloro-5,5′-dimethylhydantoin and <i style="">N-</i>bromosuccinimide <br/> <br/>Authors: Jagdale, Arun R; Chouthaiwale, Pandurang V; Sudalai, Arumugam <br/> <br/>Abstract: Copper(II) triflate catalyses efficiently the <i style=""><img src='/image/spc_char/alpha.gif'></i>-halogentaion of aryl or alkyl ketones with 1,3-dichloro-5,5′-dimethyl­hydantoin and <i style="">N</i>-bromosuccinimde to give the corresponding <img src='/image/spc_char/alpha.gif'>,<img src='/image/spc_char/alpha.gif'>-dichloroketones and <img src='/image/spc_char/alpha.gif'>-bromoketones in high yield with excellent product selectivity. <br/> <br/>Page(s): 1424-1430 Mon, 28 Sep 2009 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/6117 Title: A convenient synthesis of 2(2-benzo[<i>b</i>]furo)indoles and benzofuropyrazoles <br/> <br/>Authors: Goudarshivannanavar, B C; Jayadevappa, H; Mahadevan, K M <br/> <br/>Abstract: A short synthesis of benzo[<i>b</i>]furo indolyls<b> 3a-g</b> from 2-acetylbenzofuran<b> 1 </b>in two steps and corresponding pyrazoles <b>4a-g </b>is described. An interesting scale-up procedure for the synthesis of 2-acetylbenzofuran is also been reported. Similarly 2-acetylbenzofurohydrazones <b>2a-g</b> is prepared from 2-acetyl benzofuran and with various phenylhydrazine hydrochlorides in presence of CH₃COONa/EtOH at RT in excellent yield (90-95%). These 2-acetyl benzofurohydrazones <b>2a-g</b> are subjected to Fischer indole cyclisation in presence of ZnCl₂ in acetonitrile as solvent to get 2(2-benzo[<i>b</i>]furo)indoles <b>3a-g </b>in good yield. <br/> <br/>Page(s): 1419-1423 Mon, 28 Sep 2009 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/6116 Title: Green synthesis of 3-(2-oxo-2<i>H</i>-chromenyl)-1-[3-(4-methoxyphenyl)[1,8]naphthyridin-2-yl]-1<i>H</i>-4-pyrazolecarbaldehydes under microwave irradiation <br/> <br/>Authors: Mogilaiah, K; Jagadeeshwar, K; Prasad, R Shiva <br/> <br/>Abstract: An efficient and convenient method is described for the synthesis of 3-(2-oxo-2<i>H</i>-chromenyl)-1-[3-(4-methoxyphenyl)­[1,8]­naphthyridin-2-yl]-1<i>H</i>-4-pyrazolecarbaldehydes from 3-[2-(3-(4-methoxyphenyl)[1,8]-naphthyridin-2-yl)ethanhydrazonyl]-2<i>H</i>-2-chromenones (hydrazones) in the presence of DMF-POCl₃ (Vilsmeier-Haack reagent) using silica gel as solid support under microwave irradiation. <br/> <br/>Page(s): 1466-1469 Mon, 28 Sep 2009 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/6115 Title: Study of [1,3] sigmatropic hydrogen migration in thymine, thymidine and thymidylic acid by AM1 method <br/> <br/>Authors: Rao, Bojja Rajeshwar <br/> <br/>Abstract: The geometry and electronic structures of thymine, thymidine and thymidylic acid involving [1,3] sigmatropic hydrogen migration in the formation of tautomers have been fully optimized and evaluated by semi-empirical molecular orbital AM1 method. In this connection, the heats of formation (<img src='/image/spc_char/delta.gif'>H_f°), dipole moments (<img src='/image/spc_char/micro.gif'>), full atomic charges, and energies of frontier molecular orbitals (E_HOMO and E_LUMO) have been calculated and discussed. The mechanistic investigation of [1,3] sigmatropic rearrangement in thymine affected in the conformational changes of thymidine and thymidylic acid has been studied by the comparison of net charges of atoms in different positions of the molecule. All tautomers of thymine, thymidine and thymidylic acid exist within the energy of 28.054 kcal/mol, 20.889 kcal/mol, and 21.124 kcal/mol respectively. Furthermore, dipole moment and atomic charges of all tautomers indicated that the dipole-dipole interactions play a vital role during the hydrogen bonding with adenine. <br/> <br/>Page(s): 1411-1418 Mon, 28 Sep 2009 22:58:59 GMT