Derivatives of 4-aryl-2,3-dihalogeno-1-naphthol

1980 ◽  
Vol 45 (10) ◽  
pp. 2700-2705 ◽  
Author(s):  
Jiří Křepelka ◽  
Viktor Zikán ◽  
Jiří Holubek ◽  
Miroslav Semonský
Keyword(s):  
Intramolecular Cyclization ◽  
Zinc Chloride ◽  
Antineoplastic Effect ◽  
Methyl Derivatives ◽  
Derivatives Of

Using intramolecular cyclization of the in situ prepared chlorides of acids XVI-XX, catalysed with zinc chloride, corresponding 4-aryl-2,3-dihalogeno-1-naphthols III-VII were prepared. Methylation or acetylation of compounds I, IV-VI gave O-methyl-derivatives VIII-XI or O-acetyl derivatives IXII-XV, respectively. Compounds III-XV displayed a weak antineoplastic effect in animals with some transplantable tumours.

Imidazo(1,2-a)indole and s-triazolo(2,3-a)indole derivatives by intramolecular cyclization of 1-(o-acetylphenytyl)azoles

1968 ◽  
Vol 46 (15) ◽  
pp. 2629-2631 ◽  
Author(s):  
Misbahul Ain Khan ◽  
J. B. Polya ◽  
Brian M. Lynch
Keyword(s):  
Magnetic Resonance ◽  
Intramolecular Cyclization ◽  
Proton Magnetic Resonance ◽  
Indole Derivatives ◽  
Ring Systems ◽  
Methyl Derivatives ◽  
Derivatives Of ◽  
Magnetic Resonance Spectra

9-Hydroxy-9-methyl derivatives of the ring systems named in the title are formed along with the expected 1-(o-acetylphenyl)azoles in the Ullmann condensations of o-bromoacetophenone with imidazole and with 1,2,4-triazole. The structures of these compounds follow from their characteristic proton magnetic resonance spectra.

Physical Properties of TCNQ Salts with N-Methyl Derivatives of Pyridine

1982 ◽  
Vol 85 (1) ◽  
pp. 257-263 ◽  
Author(s):  
A. Graja ◽  
M. Przybylski ◽  
B. Butka ◽  
R. Swietlik
Keyword(s):  
Physical Properties ◽  
Methyl Derivatives ◽  
Derivatives Of

Methyl derivatives of furan

1974 ◽  
Vol 39 (11) ◽  
pp. 3109-3116 ◽  
Author(s):  
J. Šrogl ◽  
M. Janda ◽  
I. Stibor ◽  
V. Skála ◽  
P. Trška ◽  
...  
Keyword(s):  
Methyl Derivatives ◽  
Derivatives Of

Some 2-substituted derivatives of 5-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acid

1981 ◽  
Vol 46 (6) ◽  
pp. 1397-1404 ◽  
Author(s):  
Rudolf Kotva ◽  
Jiří Křepelka ◽  
Antonín Černý ◽  
Vojtěch Pujman ◽  
Miroslav Semonský
Keyword(s):  
Point Of View ◽  
Pentanoic Acid ◽  
Antineoplastic Effect ◽  
Derivatives Of

On condensation of 6-substituted trialkyl esters of 2-carboxy-1,7-heptanedioic acids XIII-XXIII with guanidineand subsequent saponification 2-substituted 5-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acids II-XII were prepared. From the pharmacological point of view some of the substances prepared had a potentiating effect on the antileukemia effect of 5-fluorouracil in mice and the antineoplastic effect manifested by a diminution of the tumours in animals with experimental tumours.

2-Substituted derivatives of 5-(4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acid

1982 ◽  
Vol 47 (9) ◽  
pp. 2525-2529 ◽  
Author(s):  
Rudolf Kotva ◽  
Jiří Křepelka ◽  
Jaroslav Vachek
Keyword(s):  
Pentanoic Acid ◽  
Antineoplastic Effect ◽  
Derivatives Of

Condensation of trialkyl esters of 6-substituted 2-carboxy-1,7-heptanedioic acids XII-XVII with urea or thiourea and subsequent saponification gave 2-substituted 5-(2,6-dihydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl)pentanoic acids II-VI or 5-(2-mercapto-6-hydroxy-4-oxo-3,4-dihydro-6-pyrimidinyl)pentanoic acids VII-XI, respectively. Compounds II, VII and X had a weak antineoplastic effect in animals with experimental transplantable tumours.

scholarly journals The Fluoride Anion-Catalyzed Sulfurization of Thioketones with Elemental Sulfur Leading to Sulfur-Rich Heterocycles: First Sulfurization of Thiochalcones

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 822
Author(s):  
Grzegorz Mlostoń ◽  
Jakub Wręczycki ◽  
Katarzyna Urbaniak ◽  
Dariusz M. Bieliński ◽  
Heinz Heimgartner
Keyword(s):  
Elemental Sulfur ◽  
Fluoride Anion ◽  
Ring Size ◽  
Mild Conditions ◽  
Tetrabutylammonium Fluoride ◽  
Cesium Fluoride ◽  
Secondary Reactions ◽  
Derivatives Of

Fluoride anion was demonstrated as a superior activator of elemental sulfur (S8) to perform sulfurization of thioketones leading to diverse sulfur-rich heterocycles. Due to solubility problems, reactions must be carried out either in THF using tetrabutylammonium fluoride (TBAF) or in DMF using cesium fluoride (CsF), respectively. The reactive sulfurizing reagents are in situ generated, nucleophilic fluoropolysulfide anions FS(8−x)−, which react with the C=S bond according to the carbophilic addition mode. Dithiiranes formed thereby, existing in an equilibrium with the ring-opened form (diradicals/zwitterions) are key-intermediates, which undergo either a step-wise dimerization to afford 1,2,4,5-tetrathianes or an intramolecular insertion, leading in the case of thioxo derivatives of 2,2,4,4-tetramethylcyclobutane-1,3-dione to ring enlarged products. In reactions catalyzed by TBAF, water bounded to fluoride anion via H-bridges and forming thereby its stable hydrates is involved in secondary reactions leading, e.g., in the case of 2,2,4,4-tetramethyl-3-thioxocyclobutanone to the formation of some unexpected products such as the ring enlarged dithiolactone and ring-opened dithiocarboxylate. In contrast to thioketones, the fluoride anion catalyzed sulfurization of their α,β-unsaturated analogues, i.e., thiochalcones is slow and inefficient. However, an alternative protocol with triphenylphosphine (PPh3) applied as a catalyst, offers an attractive approach to the synthesis of 3H-1,2-dithioles via 1,5-dipolar electrocyclization of the in situ-generated α,β-unsaturated thiocabonyl S-sulfides. All reactions occur under mild conditions and can be considered as attractive methods for the preparation of sulfur rich heterocycles with diverse ring-size.

O'-Methyl derivatives of arabinosylcytosine

1972 ◽  
Vol 46 (4) ◽  
pp. 1734-1741 ◽  
Author(s):  
E. Darżynkiewicz ◽  
J.T. Kuśmierek ◽  
D. Shugar
Keyword(s):  
Methyl Derivatives ◽  
Derivatives Of
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