ABSTRACT
[reaction: see text] Reaction of 5,5-dimethyl-3-pyrazolidinone (1) with 2-indanone (2) gave 5,5-dimethyl-2-(1H-indenyl-2)-3-pyrazolidinone (3) instead of the expected azomethine imine 4. Although reaction of 2-substituted 3-pyrazolidinones with acetylenedicarboxylates usually gives ring expansion products, such as 1,2-diazepines, treatment of 3 with dialkyl acetylenedicarboxylates (5, R = Me; 6 R = Et) resulted in the formation of rel-(7aR,12aS)-6,7-bis(alkoxycarbonyl)-3,4-dihydro-4,4-dimethyl-7aH-indano[1,2-b]pyrrolo[1,2-a]pyrimidin-2-ones (7, R = Me; 9, R = Et) as major products and 3,4-bis(alkoxycarbonyl)-7,7-dimethyl-2-(indenyl-2)-6,7-dihydro-2H,6H-1,2-diazepin-5-ones (8, R = Me: 10, R = Et) as minor products.
ABSTRACT
The antibacterial tests of two bismuth(III)-ciprofloxacin (cf) compounds against Helicobacter pylori (H. pylori) and some other bacteria were performed. The results have shown that the activity of both compounds is comparable to that of ciprofloxacin hydrochloride. The crystal structure of (cfH2)2[Bi2Cl10].4H2O (cfH2 = doubly protonated molecule of cf) is presented and discussed. The compound was isolated from acidic medium where quinolone is protonated and thus no bonding between quinolone and bismuth was observed. The bismuth(III) ions are coordinated by chloride ions forming dinuclear [Bi2Cl10]4- anions. The charge of this ion is compensated with protonated quinolone molecules (ionic interactions).
Subject(s)
Anti-Infective Agents/pharmacology , Bismuth/pharmacology , Ciprofloxacin/analogs & derivatives , Fluoroquinolones , Helicobacter pylori/drug effects , Organometallic Compounds/pharmacology , Ciprofloxacin/pharmacology , Crystallography, X-Ray , Enterococcus/drug effects , Hydrogen Bonding , Microbial Sensitivity Tests , Models, Molecular , Streptococcus/drug effects , Structure-Activity RelationshipABSTRACT
The crystal and molecular structure of one imidazo[1,2-a]-s-triazine nucleoside and its antiviral activity are described. The crystal structure of 2-amino-8-(beta-D-ribofuranosyl)imidazo[1,2-a]-s-triazin-4-one monohydroate (C10H13N5O5.H2O) was solved by X-ray counter data. The compound crystallizes in the monoclinic space group P21 with cell dimensions a = 7.353 (1), b = 6.465 (1), c = 13.701 (1) A, B = 104.64 (1) degrees. The structure was solved by direct methods and refined by full matrix least-squares technique to a final value of the conventional R-factor of 0.049 using 1998 observed intensities. The orientation of the base relative to the sugar ring defined in terms of rotating about the C(1')-N(8) glycosyl bond is anti (47.8 degrees). The ribose moiety exhibits C(2')-endo, E conformation. The conformation around C(4')-C(5') is gauche-. Molecular packing is dominated by hydrogen bonds. Base stacking occurs long the b axis. 5-Aza-7-deazaguanosine has shown a marked antiviral activity in vitro against herpes simplex virus despite the fact that N(3) is effective as the hydrogen acceptor only.
