Geometric isomers of O-alkylbenzohydroximoyl chlorides. Synthesis, identification, and acid-catalyzed isomerization

1976 ◽  
Vol 41 (2) ◽  
pp. 252-259 ◽  
Author(s):  
James E. Johnson ◽  
Elizabeth A. Nalley ◽  
Yvonne K. Kunz ◽  
John R. Springfield
Keyword(s):  
Geometric Isomers ◽  
Acid Catalyzed

Antiaminic agents derived from thieno[2,3-c]-2-benzothiepin: 4-(1-Methyl-4-piperidylidene)-4,9-dihydrothieno[2,3-c]-2-benzothiepin and some related compounds

1983 ◽  
Vol 48 (2) ◽  
pp. 623-641 ◽  
Author(s):  
Zdeněk Polívka ◽  
Miroslav Rajšner ◽  
Jan Metyš ◽  
Jiří Holubek ◽  
Emil Svátek ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Sulfuric Acid ◽  
Title Compound ◽  
Amino Alcohol ◽  
Hydrogen Sulfate ◽  
Geometric Isomers ◽  
Pure Alcohol ◽  
Acid Catalyzed ◽  
Anticataleptic Activity ◽  
Related Compounds

In the reaction of thieno[2,3c]-2-benzothiepin-4(9H)-one (VI) with 1-methyl-4-piperidylmagnesium chloride 7-(1-methyl-4-piperidyl)thieno[2,3-c]-2-benzothiepin-4(9H)-one (VIII) is formed in addition to the expected amino alcohol VII. The title compound I was obtained by the acid catalyzed dehydration of the pure alcohol VII. Compound I (pipethiadene) has outstanding antihistamine, antiserotonin, antireserpine and anticataleptic activity and was recommended to clinical trials as a potential antimigraine agent. For pharmacokinetic and metabolic studies there were prepared the NC2H3 analogue of pipethiadene IV and further, as potential metabolites, the demethyl analogue III, S-oxide X, demethyl S-oxide XI, N-oxide XIII and N,S-dioxide XIV. The Witting reaction of the ketone VI with 3-dimethylaminopropylidenetriphenylphosphorane resulted in a mixture of geometric isomers of 4-(3-dimethylamino-propylidene)-4,9-dihydrothieno[2,3-c]-2-benzothiepin with the strongly predominating Z-isomer XVI which was isolated from the mixture by crystallization of the hydrogen maleate. The mixture with the predominating Z-isomer XVI was converted by the treatment with 80% sulfuric acid and dilution with water to a mixture with the predominating E-isomer XV (dithiadene) which was isolated by crystallization of the hydrogen sulfate. Some further new thieno[2,3-c]-2-benzothiepin derivatives were synthesized as potential intermediates.

Potential metabolites of the neuroleptic agent chlorprothixene; synthesis and pharmacology of the 3-, 4-, 6- and 7-hydroxy and methoxy derivatives of 2-chloro-9-(3-dimethylaminopropylidene)-thioxanthenes

1980 ◽  
Vol 45 (11) ◽  
pp. 3166-3181 ◽  
Author(s):  
Karel Šindelář ◽  
Jiří Jílek ◽  
Jiří Körbl ◽  
Fedir Jančik ◽  
Emil Svátek ◽  
...  
Keyword(s):  
Ir Spectra ◽  
Polyphosphoric Acid ◽  
Amino Alcohols ◽  
Geometric Isomers ◽  
Pyridine Hydrochloride ◽  
Neuroleptic Agent ◽  
Acid Catalyzed ◽  
Boron Tribromide ◽  
Derivatives Of ◽  
Central Depressant

Cyclization of the acids IV-VII with sulfuric or polyphosphoric acid resulted in the thioxanthones VIIIa-d which were treated with 3-dimethylaminopropylmagnesium chloride and gave the amino alcohols Xa-d. Their acid catalyzed dehydrations afforded the methoxy derivatives of chlorprothixene IIIa-d, mostly in form of mixtures of geometric isomers. Whereas the results of attempts to demethylate these products with boron tribromide gave mostly unsatisfactory results, the demethylation with pyridine hydrochloride at 190-200 °C was successful; alcohols X were the most suitable starting materials. In this manner, the hydroxy derivatives of chloroprothixene IIa-d were obtained, mostly as pure geometric isomers. The configuration was assigned on the basis of their IR spectra. Z-Isomers are potential metabolites of the neuroleptic agent chlorprothixene (I). Compounds II and III are little toxic, have low central depressant activity and are inactive cataleptically.

ChemInform Abstract: GEOMETRIC ISOMERS OF O-ALKYLBENZOHYDROXIMOYL CHLORIDES. SYNTHESIS, IDENTIFICATION, AND ACID-CATALYZED ISOMERIZATION

1976 ◽  
Vol 7 (18) ◽  
pp. no-no
Author(s):  
J. E. JOHNSON ◽  
E. A. NALLEY ◽  
Y. K. KUNZ ◽  
J. R. SPRINGFIELD
Keyword(s):  
Geometric Isomers ◽  
Acid Catalyzed

Acid Catalyzed Furan Ring Transposition

10.1039/sp768 ◽  
2014 ◽  
Author(s):  
Jamsheena V. ◽  
Ravindra Phatake
Keyword(s):  
Furan Ring ◽  
Acid Catalyzed

Catalytic Carbonyl-Olefin Metathesis of Aliphatic Ketones: Iron(III) HomoDimers as Lewis Acidic Superelectrophiles

2018 ◽  
Author(s):  
Haley Albright ◽  
Paul S. Riehl ◽  
Christopher C. McAtee ◽  
Jolene P. Reid ◽  
Jacob R. Ludwig ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Olefin Metathesis ◽  
Acid Activation ◽  
Lewis Acid Catalysts ◽  
Distinct Mode ◽  
Aliphatic Ketones ◽  
Carbon Carbon Bond ◽  
Metathesis Reactions ◽  
Acid Catalyzed

<div>Catalytic carbonyl-olefin metathesis reactions have recently been developed as a powerful tool for carbon-carbon bond</div><div>formation. However, currently available synthetic protocols rely exclusively on aryl ketone substrates while the corresponding aliphatic analogs remain elusive. We herein report the development of Lewis acid-catalyzed carbonyl-olefin ring-closing metathesis reactions for aliphatic ketones. Mechanistic investigations are consistent with a distinct mode of activation relying on the in situ formation of a homobimetallic singly-bridged iron(III)-dimer as the active catalytic species. These “superelectrophiles” function as more powerful Lewis acid catalysts that form upon association of individual iron(III)-monomers. While this mode of Lewis acid activation has previously been postulated to exist, it has not yet been applied in a catalytic setting. The insights presented are expected to enable further advancement in Lewis acid catalysis by building upon the activation principle of “superelectrophiles” and broaden the current scope of catalytic carbonyl-olefin metathesis reactions.</div>

Arylboronic Acid-Catalyzed C-Allylation of Unprotected Oximes

2019 ◽  
Author(s):  
Juha Siitonen ◽  
Padmanabha V. Kattamuri ◽  
Muhammed Yousufuddin ◽  
Laszlo Kurti
Keyword(s):  
Total Synthesis ◽  
Acid Catalysts ◽  
Mechanistic Studies ◽  
Arylboronic Acid ◽  
Synthetic Utility ◽  
Acid Catalyzed

Unprotected keto- and aldoximes are readily <i>C</i>-allylated with allyl diisopropyl boronate in the presence of arylboronic acid catalysts to yield highly-substituted <i>N</i>-alpha-secondary (2°) and tertiary (3°) hydroxylamines. The method’s synthetic utility is demonstrated with the total synthesis of the trace alkaloid <i>N</i>-methyl-euphococcine. Preliminary experimental and computational mechanistic studies point toward the formation of a boroxine as the active allylating species.<br>

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