http://nopr.niscair.res.in/handle/123456789/1723 <b>Special Issue on Recent Developments in Heterocyclic Chemistry</b> Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/3850 Title: Dynamic ¹H NMR study of rotational energy barrier around the aryl-nitrogen single bond in γ-spiroiminolactones derived from reaction between 2,6-dimethylphenyl isocyanide and dialkyl acetylenedicarboxylates in the presence of phendione <br/> <br/>Authors: Maghsoodlou, Malek Taher; Marandi, Ghasem; Khorassani, Mostafa Habibi; Saghatforoush, Lotfali; Aminkhani, Ali; Kabiri, Roya <br/> <br/>Abstract: The Dynamic effects are observed in ¹H NMR spectra of highly functional γ-spiroiminolactones such as dimethyl-5-(2,6-dimethylphenylimino)-6'-oxo-5H,6H'-spiro[furan-2,5'-[1,10]-phenanthroline]-3,4-dicarboxylate and di-tert-butyl-5-(2,6-dimethylphenylimino)-6'-oxo-5H, 6H'-spiro[furan-2, 5'-[1,10]phenanthroline]-3,4-dicarboxylate. The calculated free-energy of activation (ΔG^≠) for restricted rotation around the aryl-nitrogen single bonds in γ-spiroiminolactones 4a and 4b amounts to (44.4 and 45.3)±2 kJ.mol^-1 with first order rate constant (k=109.9 and 111.0 s^-1) at appropriate temperature respectively. <br/> <br/>Page(s): 1151-1153 http://nopr.niscair.res.in/handle/123456789/1768 Title: MgCl₂•6H₂O/p-TSA catalyzed simple and efficient synthesis of some known and novel quinolines <br/> <br/>Authors: Pasha, M A; Jayashankara, V P; Mahammed, K A <br/> <br/>Abstract: A simple and efficient method has been developed for the synthesis of some important fused quinolines from o-aminoaryl ketones and α-methylene ketones in the presence of catalytic amounts of MgCl₂•6H₂O/p-TSA in high yield. The reaction works at ambient temperature to give the products within 40 min. <br/> <br/>Page(s): 1160-1164 http://nopr.niscair.res.in/handle/123456789/1767 Title: A mild, efficient and one-pot synthesis of 2-substituted benzimidazoles by ZrOCl₂.8H₂O catalyzed ring closure reaction <br/> <br/>Authors: Reddy, Ch Sanjeeva; Nagaraj, A <br/> <br/>Abstract: A mild, efficient and one-pot synthesis of an array of 2-substituted benzimidazoles from an appropriate o-phenylenediamine and orthoesters such as orthoformate, orthoacetate and orthovalerate using ZrOCl₂.8H₂O, at room temperature and under microwave irradiation is described. Eco-friendly, solvent-free methodology has been employed under microwave condition. Compared with the conventional method, microwave irradiation method has the advantages of excellent yields (81-93%) and shorter reaction time (5-10 min). <br/> <br/>Page(s): 1154-1159 http://nopr.niscair.res.in/handle/123456789/1765 Title: Synthesis and cytotoxicity studies of thiazole analogs of the anticancer marine alkaloid dendrodoine <br/> <br/>Authors: Reji, T F Abbs Fen; Devi, S K C; Thomas, K K; Sreejalekshmi, K G; Manju, S L; Francis, M; Philip, S K; Bharathan, A; Rajasekharan, K N <br/> <br/>Abstract: The synthesis and cytotoxicity evaluation of 2-N,N-dimethylamino-5-indol-3-oylthiazole as the first member of a new portfolio of the thiazole analogs of the cytotoxic marine alkaloid dendrodoine (3-N,N-dimethylamino-5-indol-3-oyl-1,2,4-thiadiazole) is described. Exploiting the opportunity arising from the replacement of the thiadiazole ring of dendrodoine by a thiazole ring which allowed further substitution on the five-membered ring, 2-N,N-dimethylamino-5-indol-3-oyl-4-phenylthiazole has also been synthesized. Structural diversity is further extended by synthesizing 5-fur-2-oyl- and 5-coumarin-3-oyl-2-N,N-dimethylaminothiazoles, as well as 5-fur-2-oyl, 5-thiophen-2-oyl, 5-(1-methylbenzimidazol-2-oyl) and 5-benzothiazol-2-oyl derivatives of 2-N,N-dimethylamino-4-phenylthiazoles. Among these new N,N-dimethylaminothiazoles, 2-N,N-dimethylamino-5-indol-3-oyl-4-phenylthiazole shows significant in vitro cytotoxicity against a panel of human cancer cell lines. <br/> <br/>Page(s): 1145-1150