5-, 6- And 7-substitution derivatives of 7-oxo-7H-benzo(c)fluorene

1982 ◽  
Vol 47 (4) ◽  
pp. 1258-1266 ◽  
Author(s):  
Jiří Křepelka ◽  
Jiří Roubík ◽  
Jiří Holubek ◽  
Iva Vančurová
Keyword(s):  
Acetyl Chloride ◽  
Hydroxylamine Hydrochloride ◽  
Acetyl Derivative ◽  
Ring Closure ◽  
Substitution Reactions ◽  
Acyl Chlorides ◽  
Chloride Method ◽  
Derivatives Of ◽  
Sole Product ◽  
Intramolecular Ring

Intramolecular ring closure of anhydrides IIa-IIc, under conditions of the Friedel-Crafts reaction, gave 6-carboxy derivatives III-V. Esterification of the acid V by the chloride method led to esters VI and VII. Reaction of the ester VI with hydrazine gave rise to compound XXI, having a pentacyclic structure. Alkylation or acylation of the 5-hydroxy group in compounds Ia-Ic with alkyl halides or acyl chlorides afforded compounds VIII-XIII and XVIII. Compound XI was also formed as a by-product in the Friedel-Crafts reaction of compound Ic with acetyl chloride in 1,2-dichloroethane, in addition to the 6-acetyl derivative XV. An analogous reaction of Ic with dichloracetyl chloride gave compound XIV as a sole product. Substitution reactions on the 7-oxo group in Ic afforded semicarbazone XVI and thiosemicarbazone XVII, and reaction of the compound XVIII with hydroxylamine hydrochloride gave the oxime XIX. The action of N-methylolchloracetamide on Ia in sulphuric acid produced compound XX. The compounds prepared proved to have no antineoplastic effects. In tests for activity against the viruses of vaccinia and encephalomyocarditis they proved to be weaker than Tiloron as control. In assessing the efficacy against influenza virus A2 Singapore compound V exhibited the same effect as Tiloron.

Synthetic use of the ribosyl derivatives of 2,4- and 2,5-thiazolidinediones

1979 ◽  
Vol 44 (5) ◽  
pp. 1475-1482 ◽  
Author(s):  
Hubert Hřebabecký ◽  
Zdeněk Točík ◽  
Jiří Beránek
Keyword(s):  
Hydrazine Hydrate ◽  
Hydrogen Chloride ◽  
Sodium Methoxide ◽  
Aqueous Ammonia ◽  
Hydroxylamine Hydrochloride ◽  
Acetyl Derivative ◽  
High Yield ◽  
Derivatives Of ◽  
Methanolic Ammonia

On ribosidation of 2,4-thiazolidinedione (2,5-thiazolidinedione, respectively), the 3-β-D-ribofuranosyl derivative is formed in high yield, either the benzoyl derivative Ia (IIa) or the acetyl derivative Ib (IIb). The unsubstituted ribosyl derivative Ic is formed from the acetyl derivative Ib by methanolic hydrogen chloride. The benzoylated ribosyl-2,4-thiazolidinedione Ia affords the benzoylated ribosylurea III on reaction with aqueous ammonia, the hydroxyethylurea derivative IVa with 2-aminoethanol, the semicarbazide derivative Va with hydrazine hydrate, the ribosylhydroxyurea derivative VIa on reaction with hydroxylamine hydrochloride and triethylamine, the benzoyl derivative of ribosylbiuret VII with O-methylisourea hydrochloride and triethylamine, and (analogously) ribosylisothiobiuret VIII with S-methylisothiourea. Methanolysis of the benzoyl derivative of hydroxyethylurea IVa with sodium methoxide affords the unprotected riboside IVb. Ribosylhydroxyurea VIb is formed on debenzoylation of compound VIa with methanolic ammonia. Acetylation of compound VIb furnishes the pentaacetyl derivative VIc.

Hydrolytic products of 4-aryl-2,3-dicyano-1-naphthol derivatives

1981 ◽  
Vol 46 (9) ◽  
pp. 2207-2216 ◽  
Author(s):  
Jiří Křepelka ◽  
Iva Vančurová ◽  
Jiří Holubek ◽  
Jiří Roubík
Keyword(s):  
Dicarboxylic Acids ◽  
Ring Closure ◽  
Partial Hydrolysis ◽  
H Nmr ◽  
Antiviral Effects ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Naphthol Derivatives ◽  
Intramolecular Ring

Depending on the conditions of hydrolysis, vicinal aromatic dicyano derivatives Ia-Ic gave anhydrides IIa-IIe and imides of 4-aryl-1-alkoxynaphthalene-2,3-dicarboxylic acids, IIIa,b, along with products of partial hydrolysis, decarboxylation and demethylation, IVa-IVd, IVf-IVg, and derivatives of benzo(c)fluorene, Va-Vc. The derivatives Va-Vc were also obtained by acid hydrolysis of dicyano derivatives Id-Ig. Methanolysis of the anhydride IId gave a mixture of positional isomers, IVh, which was esterified to the diester IVe. Intramolecular ring closure of the isomers IVh afforded derivatives of benzo(c)fluorene, VIa-VIb. The structures of the selected compounds were corroborated by IR and 1H NMR spectra. The compounds Va-Vc exhibited antiviral effects and interferonogenic activities in vivo.

The role of secondary alcoholic groups of D-galacturonan in its degradation with exo-D-galacturonanase

1980 ◽  
Vol 45 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Kveta Heinrichová ◽  
Rudolf Kohn
Keyword(s):  
Acetyl Derivative ◽  
Competitive Inhibitor ◽  
Hydroxyl Groups ◽  
Pectic Acid ◽  
Substrate Complex ◽  
Enzyme Substrate ◽  
The Individual ◽  
Degradation Degree ◽  
Derivatives Of

The effect of exo-D-galacturonanase from carrot on O-acetyl derivatives of pectic acid of variousacetylation degree was studied. Substitution of hydroxyl groups at C(2) and C(3) of D-galactopyranuronic acid units influences the initial rate of degradation, degree of degradation and its maximum rate, the differences being found also in the time of limit degradations of the individual O-acetyl derivatives. Value of the apparent Michaelis constant increases with increase of substitution and value of Vmax changes. O-Acetyl derivatives act as a competitive inhibitor of degradation of D-galacturonan. The extent of the inhibition effect depends on the degree of substitution. The only product of enzymic reaction is D-galactopyranuronic acid, what indicates that no degradation of the terminal substituted unit of O-acetyl derivative of pectic acid takes place. Substitution of hydroxyl groups influences the affinity of the enzyme towards the modified substrate. The results let us presume that hydroxyl groups at C(2) and C(3) of galacturonic unit of pectic acid are essential for formation of the enzyme-substrate complex.

Fluorinated tricyclic neuroleptics with prolonged action: 8-Methoxy, 8-ethoxy, 8-ethylthio and 8-hydroxy derivatives of 3-fluoro-10-(4-methylpiperazino)-10,11-dihydrodibenzo[b,f]thiepin

1982 ◽  
Vol 47 (5) ◽  
pp. 1382-1391 ◽  
Author(s):  
Jiří Jílek ◽  
Josef Pomykáček ◽  
Jiřina Metyšová ◽  
Miroslav Protiva
Keyword(s):  
Acetic Acid ◽  
Polyphosphoric Acid ◽  
Prolonged Action ◽  
Substitution Reactions ◽  
Methoxy Derivative ◽  
Chloro Derivatives ◽  
Boron Tribromide ◽  
Derivatives Of ◽  
Central Depressant ◽  
Boiling Toluene

Acids IIa-c were prepared by reactions of (4-fluoro-2-iodophenyl)acetic acid with 4-methoxythiophenol, 4-ethoxythiophenol and 4-(ethylthio)thiophenol and cyclized with polyphosphoric acid in boiling toluene to dibenzo[b,f]thiepin-10(11H)-ones IIIa-c. Reduction with sodium borohydride afforded the alcohols IVa-c which were treated with hydrogen chloride and gave the chloro derivatives Va-c. Substitution reactions with 1-methylpiperazine resulted in the title compounds Ia-c out of which the methoxy derivative Ia was transformed by demethylation with boron tribromide to the phenol Id. Compounds Ia-d are very potent neuroleptics exhibiting a clear prolongation of the central depressant and some prolongation of the cataleptic activity.

Substitution Reactions and Meso Derivatives of 1,2-Benzanthracene

1938 ◽  
Vol 60 (8) ◽  
pp. 1893-1896 ◽  
Author(s):  
Louis F. Fieser ◽  
E. B. Hershberg
Keyword(s):  
Substitution Reactions ◽  
Derivatives Of

Synthesis of azaanthraquinones: homolytic substitution of pyridines

1982 ◽  
Vol 35 (7) ◽  
pp. 1451 ◽  
Author(s):  
DW Cameron ◽  
KR Deutscher ◽  
GI Feutrill ◽  
DE Hunt
Keyword(s):  
Ring Closure ◽  
Pyridine Derivatives ◽  
Derivatives Of ◽  
Substituted 1 ◽  
Homolytic Substitution

Synthesis of specific di- and tri-hydroxyazaanthraquinones by Friedel-Crafts procedures is limited by orientational ambiguity and by the lack of reactivity of pyridine derivatives in electrophilic acylation processes; however, suitable pyridines have been made to undergo radical benzoylation and benzylation at unsubstituted positions 2, 4 and 6. In particular, derivatives of pyridine-3-carbo-nitrile have been benzoylated at positions 2 and 4. Ring closure by intramolecular Houben-Hoesch reaction has then led to specifically substituted 1-and 2-azaanthraquinones and thence to the antibiotic bostrycoidin (1).

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