Aryl Thioethers Research Articles

The ultraviolet absorption spectra, and the cyanohydrin equilibria of some acetyl derivatives of aryl ethers and thioethers

The equilibrium constants for the reaction: keton + HCN ⇄ cyanohydrin, are reported for the ketones Ib and IIIb (R = Me, Et, Pr i), Ib (R = Bu t) and IVb (n = 1, 2, and 3). The data for the equilibria reveal a progressive decrease in the stability of the ketone (relative to its cyanohydrine) in the order: Me > Et > Pr i > Bu t, and n = 1 > 2 > 3. This is attributed to increased steric interactions between R and an o-hydrogen atom in Ib and IIIb, and in the saturated hetero-ring in IVb. The same type of steric interaction is believed to operate in the spectroscopically excited states of IB, where it opposes the stabilizing inductive effect of R, thus causing the observed trends in the spectra.

The Magnetic Anisotropy of the Aromatic Ring, Aryl Thioethers and Sulfones

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Magnetic Anisotropy of the Aromatic Ring, Aryl Thioethers and SulfonesH. Agahigian and G. D. VickersCite this: J. Org. Chem. 1962, 27, 9, 3324–3325Publication Date (Print):September 1, 1962Publication History Published online1 May 2002Published inissue 1 September 1962https://doi.org/10.1021/jo01056a514RIGHTS & PERMISSIONSArticle Views54Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (249 KB) Get e-Alerts Get e-Alerts

Raney Niを用いる芳香複素環N-オキシドの接触還元 (第5報) 含硫黄置換基を有するN-オキシドの還元

Catalytic reduction at ordinary temperature and pressure over Raney nickel was carried out on N-oxide compounds with sulfur-containing substituent, 4-phenylthiopyridine 1-oxide (I), phenyl 4-pyridyl sulfone 1-oxide (II), 4-ethylthiopyridine 1-oxide (III), and sodium salt (IV) of 4-mercaptoquinoline 1-oxide. (I) and (II) underwent rapid reduction, as in the case of previously reported N-oxides, and respectively afforded 4-phenylthiopyridine (V) and phenyl 4-pyridyl sulfone (VI). In the case of (III), absorption of hydrogen stopped after about one-half the calculated amount of hydrogen had been absorbed and a part of the starting material was recovered together with 4-ethylpyridine (VII). This fact suggests that the sulfone group might work as a catalyst poison but thioether in aryl thioethers has not proved to be of great hazard. In the case of alkyl thioethers, the thioether group does act as a catalyst poison but the action of Raney nickel on the N-oxide group is so great that the reduction proceeds with considerable speed before the catalyst loses its activity. In the case of (IV), absorption of hydrogen also stops after about one-half the theoretical amount had been absorbed, and quinoline (VIII) and 4, 4′-diquinolyl sulfide 1, 1′-dioxide (IX) are obtained. This shows that the reduction of N-oxide group is followed by desulfurization by Raney nickel, by which the catalytic activity of Raney nickel is lost, and the unreacted material (IV) changes into (IX) during aftertreatment. 4-Mercaptoquinoline 1-oxide (X) itself does not undergo reduction of the N-oxide group and the starting compound is recovered almost completely.