title: Regioselectivity and tautomerism of novel five-membered ring nitrogen heterocycles formed via cyclocondensation of acylthiosemicarbazides.
abstract: A series of 1-acyl-4-phenyl/(acridin-9-yl)thiosemicarbazides 3, including four new compounds, were prepared in order to study substituent effects on cyclization reactions with oxalyl chloride (producing imidazolidine-4,5-diones 4), dimethyl acetylenedicarboxylate (to give thiazolidin-4-ones 7 and 8) and autocondensation under alkaline conditions (to yield 1,2,4-triazoles 9). A positional isomer, 10 of compound 3f was also prepared. Altogether, twenty new compounds characterized and identified by IR, UV,1H, 13C and 2D NMR and quantum chemical calculations are described. The tautomerism of the products and regioselectivity of the reactions were evaluated. Compounds 3f-h,3h.2HCl, 7b,d and 10 were screened for cytotoxic activity against the L1210 leukemia cell line and all compounds, except for 3f, exhibited promising inhibitions of cell growth.
authors.affiliation: Institute of Chemistry, Faculty of Science, P. J. Safárik University, SK-041 67 Kosice, Slovak Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Tomasciková
authors.forename: Ján
authors.initials: J
authors.lastname: Imrich
authors.forename: Ivan
authors.initials: I
authors.lastname: Danihel
authors.forename: Stanislav
authors.initials: S
authors.lastname: Böhm
authors.forename: Pavol
authors.initials: P
authors.lastname: Kristian
authors.forename: Jana
authors.initials: J
authors.lastname: Pisarcíková
authors.forename: Marián
authors.initials: M
authors.lastname: Sabol
authors.forename: Karel D
authors.initials: KD
authors.lastname: Klika
mesh_terms: D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D003500:Cyclization / Q000187:drug effects; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006834:Hydrazines / Q000737:chemistry; D017879:Isothiocyanates / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009584:Nitrogen / Q000737:chemistry*; D012663:Semicarbazides / Q000737:chemistry* / Q000494:pharmacology; D013237:Stereoisomerism
chemical_list: D006571:Heterocyclic Compounds; D006834:Hydrazines; D017879:Isothiocyanates; D012663:Semicarbazides; D009584:Nitrogen