Photochemical syntheses. III. The synthesis and photo-isomerization of 1,2-Diphenyl-2a,8b-dihydrocyclobuta[a]naphthalene and some derivatives

1971 ◽  
Vol 24 (11) ◽  
pp. 2325 ◽  
Author(s):  
PJ Collin ◽  
WHF Sasse
Keyword(s):  
Methoxy Derivative ◽  
High Yields ◽  
Derivatives Of

Fourteen derivatives of the naphthalene-diphenylacetylene photo-adduct (1a) have been thermally isomerized to give high yields of derivatives of 1,2-diphenyl-2a,8b-dihydrocyclobuta[a]naphthalene (1b). Of these only the 4-methoxy derivative (13b) could be rearranged to the isomeric benzocyclooctatetraene (13c). Five alkyl and one methoxy derivative of (1b) were quantitatively isomerized to derivatives of (1a) but the isomerization of the esters (10b) and (11b) gave mixtures. Photo-iso- merization of the methoxybenzocyclooctatetraene (13c) gave exclusively (13b) and (13a). ��� Mechanistic aspects of these reactions are discussed.

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.

scholarly journals Synthesis and anticonvulsant activity of 6-methyl-2-((2-oxo-2-arylethyl)thio)pyrimidin-4(3 H)-one derivatives and products of their cyclization

Pharmacia ◽  
2019 ◽  
Vol 66 (3) ◽  
pp. 141-146
Author(s):  
Hanna Severina ◽  
Olga O. Skupa ◽  
Natalya I. Voloshchuk ◽  
Marharyta M. Suleiman ◽  
Victoriya A. Georgiyants
Keyword(s):  
Sulphuric Acid ◽  
Anticonvulsant Activity ◽  
Sodium Methoxide ◽  
Structure Activity ◽  
Phenacyl Bromides ◽  
Pharmacological Screening ◽  
High Yields ◽  
Derivatives Of

The alkylation of 6-methyl-2-thioxo-2,3-dihydro-1H-pyrimidine-4-one phenacyl bromides under different conditions was investigated. It was found that during the reaction in the medium of DMF/K2CO3 a mixture of 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one and 3-hydroxy-3-aryl-7-methyl-2,3-dihydro-5H-thiazolo[3,2-a]pyrimidine-5-one was formed. The holding of the resulting mixture in the concentrated sulphuric acid leads to the formation of cyclization products - derivatives of 3-aryl-7-methyl-5H-thiazolo[3,2-a]pyrimidin-5-one with high yields. Individual S-alkylated derivatives – 2-(2-aryl-2-oxoethyl)thio-6-methyl-pyrimidine-4(3H)-one - were obtained by reacting in methanol in the presence of sodium methoxide. Pharmacological screening of synthesized compounds for anticonvulsant activity on the model of pentylenetetrazole seizures in rats was carried out and some regularity “structure-activity” was established.

scholarly journals The first in situ synthesis of 1,3-dioxan-5-one derivatives and their direct use in Claisen-Schmidt reactions

2019 ◽  
Vol 25 (1) ◽  
pp. 85-90 ◽  
Author(s):  
M. Javad Poursharifi ◽  
Mohammad M. Mojtahedi ◽  
M. Saeed Abaee ◽  
Mohammad M. Hashemi
Keyword(s):  
Acetic Acid ◽  
Aromatic Aldehydes ◽  
In Situ Synthesis ◽  
Stepwise Procedures ◽  
Time Periods ◽  
High Yields ◽  
Short Time ◽  
Direct Use ◽  
Derivatives Of

AbstractA method is developed for in situ generation of 1,3-dioxan-5-one derivatives 2. These compounds are simple precursors for accessing carbohydrate structures and previously had to be produced via stepwise procedures using excessive amounts of reagents. In the present work, three different derivatives of 2 were synthesized via the reaction of trialkoxyalkanes with dihydroxyacetone dimer 1 in the presence of acetic acid as the catalyst. In the same pot, derivatives of 2 were reacted with aromatic aldehydes and 30 mol% of pyrrolidine to obtain high yields of the respective bischalcones 3 within short time periods.

scholarly journals Active Anti-Inflammatory and Hypolipidemic Derivatives of Lorazepam

Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3277
Author(s):  
Panagiotis Theodosis-Nobelos ◽  
Georgios Papagiouvannis ◽  
Panos N. Kourounakis ◽  
Eleni A. Rekka
Keyword(s):  
Acute Inflammation ◽  
Current Knowledge ◽  
Rat Plasma ◽  
Straightforward Method ◽  
Inflammatory Drugs ◽  
Multifunctional Agents ◽  
Anti Inflammatory ◽  
High Yields ◽  
Derivatives Of ◽  
And Oxidative Stress

Novel derivatives of some non steroidal anti-inflammatory drugs, as well as of the antioxidants α-lipoic acid, trolox and (E)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)acrylic acid with lorazepam were synthesised by a straightforward method at satisfactory to high yields (40%–93%). All the tested derivatives strongly decreased lipidemic indices in rat plasma after Triton induced hyperlipidaemia. They also reduced acute inflammation and a number of them demonstrated lipoxygenase inhibitory activity. Those compounds acquiring antioxidant moiety were inhibitors of lipid peroxidation and radical scavengers. Therefore, the synthesised compounds may add to the current knowledge about multifunctional agents acting against various disorders implicating inflammation, dyslipidaemia and oxidative stress.

scholarly journals Highly Asymmetric Reduction of New Benzofuryl and Benzothiophenyl α-Amino Ketones

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 49
Author(s):  
Agnieszka Tafelska-Kaczmarek ◽  
Marcin Kwit ◽  
Bartosz Stasiak
Keyword(s):  
High Performance ◽  
Asymmetric Reduction ◽  
Theoretical Calculations ◽  
Transfer Hydrogenation ◽  
Central Position ◽  
Chiral Hplc ◽  
Naturally Occurring ◽  
Approved Drugs ◽  
High Yields ◽  
Derivatives Of

Heterocyclic compounds play an important role in medicinal chemistry and occupy a central position in synthetic organic chemistry. Both benzofuran and benzothiophene are considered as very important structures due to their diverse biological and pharmacological profile. Many clinically approved drugs are synthetic and naturally occurring substituted benzofuryl and benzothiophenyl derivatives in conjunction with other heterocycles. Therefore, a new series of α-amino ketone (containing various azole rings) derivatives of benzofuran and benzothiophene are synthesized and subjected to the transfer hydrogenation with formic acid, catalyzed by RhCl[(R,R)-TsDPEN](C5Me5). The corresponding optically active β-amino alcohols are obtained in high yields and excellent enantioselectivities (93%–99%), as determined by chiral HPLC (high-performance liquid chromatography). The absolute configuration of the products is confirmed by means of ECD (electronic circular dichroism) spectroscopy, supported by theoretical calculations.

Introduction of 9-fluorenylmethyloxycarbonyl, trichloroethoxycarbonyl, and benzyloxycarbonyl amine protecting groups into O-unprotected hydroxyamino acids using succinimidyl carbonates

1982 ◽  
Vol 60 (8) ◽  
pp. 976-980 ◽  
Author(s):  
Alenka Paquet
Keyword(s):  
Benzyl Ester ◽  
Protecting Groups ◽  
Efficient Conversion ◽  
Hydroxyamino Acids ◽  
High Yields ◽  
Derivatives Of ◽  
Acid Esters ◽  
Efficient Reagent

9-Fluorenylmethyl succinimidyl, pentachlorophenyl, and benzotriazole-1-yl carbonates were prepared and their reactivity with L-serine and L-serine benzyl ester was compared. The most efficient reagent, 9-fluorenylmethyl succinimidyl carbonate, was used for the preparation of 9-fluorenylmethyloxycarbonyl derivatives of other hydroxyamino acids and hydroxyamino acid esters in high yields. The use of trichloroethyl and benzyl succinimidyl carbonates for an efficient conversion of hydroxyamino acids and their esters into the corresponding N-trichloroethoxycarbonyl and benzyloxycarbonyl derivatives is described.

Zirconium-Catalyzed Alkyne Carbo- and Cycloalumination Reactions in Stereoselective Preparation of 1-Alkenyl Selenides

Synthesis ◽  
2017 ◽  
Vol 28 (19) ◽  
pp. 4523-4534 ◽  
Author(s):  
Rita Kadikova ◽  
Ilfir Ramazanov ◽  
Alexey Vyatkin ◽  
Usein Dzhemilev
Keyword(s):  
One Pot ◽  
Versatile Tool ◽  
High Yields ◽  
Derivatives Of

The Cp2ZrCl2-catalyzed methylalumination and сycloalumination of 1-alkynyl selenides followed by deuterolysis or hydrolysis affords corresponding (Z)-1-alkenyl selenides in high yields. Alternatively, (E)-1-alkenyl selenides were prepared by the reaction of 1-alkenylaluminums with organic diselenides in a one-pot procedure starting from the corresponding 1-alkynes, which provides a versatile tool for the preparation of stereo-defined unsaturated organic derivatives of selenium.

HYDROLYSIS AND HYDRAZINOLYSIS OF ESTERS OF N,N-DIMETHYLDITHIOCARBAMIC ACID: A METHOD FOR THE PREPARATION OF MERCAPTANS

1956 ◽  
Vol 34 (8) ◽  
pp. 1093-1100 ◽  
Author(s):  
Marshall Kulka
Keyword(s):  
Alkaline Hydrolysis ◽  
Alkyl Chain ◽  
Wide Scope ◽  
Nitro Derivatives ◽  
High Yields ◽  
Derivatives Of ◽  
Oxygen Bond ◽  
Dimethyl Dithiocarbamate

A method has been developed for the preparation of mercaptans from alkyl and aralkyl chlorides. This consists of the condensation of sodium N,N-dimethyl-dithiocarbamate with halides followed by alkaline hydrolysis or hydrazinolysis of the resulting N,N-dimethyldithiocarbamates (IV). In the hydrazinolysis of IV, an insoluble solid by-product was formed which was identified as 3-hydrazino-4-amino-5-mercapto-4,1,2-triazole. Although this method was found to have wide scope a few failures were encountered. Nitro-derivatives of IV were sensitive to alkali or hydrazine and yielded only tars on attempted degradation. β-Phenoxyethyl N,N-dimethyldithiocarbamates (IX) were found to possess a labile alkyl–oxygen bond so that in the presence of alkali or hydrazine only the corresponding phenols were formed. The labile nature of the alkyl–oxygen bond ceased abruptly when the alkyl chain of IX was increased so that 3-p-chlorophenoxypropyl and 4-p-chlorophenoxybutyl mercaptans could be prepared in high yields.

Reaction of 5-Chloroalkyl-3-phenyl-4,5-dihydroisoxazoles with strong base. An unexpected new synthesis of the 2-Oxa-3-azabicyclo[3,1,0]hex-3-ene ring system

1977 ◽  
Vol 30 (8) ◽  
pp. 1855 ◽  
Author(s):  
TG Burrowes ◽  
WR Jackson ◽  
S Faulks ◽  
I Sharp
Keyword(s):  
Ring System ◽  
Dimethyl Sulphoxide ◽  
High Yield ◽  
Strong Base ◽  
Bicyclic Compounds ◽  
New Synthesis ◽  
Bicyclic System ◽  
Methyl Derivatives ◽  
High Yields ◽  
Derivatives Of

Reaction of 5-chloromethyl-3-phenyl-4,5-dihydroisoxazole with potassium t-butoxide in dimethyl sulphoxide gives 4-phenyl-2-oxa-3- azabicyclo[3,1,0]hex-3-ene in high yield and reaction of the 5-(1?- chloroethyl) homologue gives high yields of the diastereoisomeric 6- methyl derivatives of the bicyclic system. Some unsuccessful attempts to convert these bicyclic compounds into substituted cyclo-propanols and cyclopropenes are described.

scholarly journals Synthesis of dibenzosuberenone-based novel polycyclic π-conjugated dihydropyridazines, pyridazines and pyrroles

2021 ◽  
Vol 17 ◽  
pp. 719-729
Author(s):  
Ramazan Koçak ◽  
Arif Daştan
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Cycloaddition Reactions ◽  
Inverse Electron Demand ◽  
Diels Alder Reaction ◽  
Reductive Treatment ◽  
High Yields ◽  
Derivatives Of ◽  
Electron Demand

The synthesis of novel polycyclic π-conjugated dihydropyridazines, pyridazines, and pyrroles was studied. Dihydropyridazine dyes were synthesized by inverse electron-demand Diels–Alder cycloaddition reactions between a dibenzosuberenone and tetrazines that bear various substituents. The pyridazines were synthesized in high yields by oxidation of dihydropyridazine-appended dibenzosuberenones with PIFA or NO. p-Quinone derivatives of pyridazines were also obtained by H-shift isomerization following the inverse electron-demand Diels–Alder reaction of tetrazines with p-quinone dibenzosuberenone. Then these pyridazines were converted to the corresponding pyrroles by reductive treatment with zinc. It was observed that all the dihydropyridazines obtained gave absorbance and emission at long wavelengths.

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