Reduction of nitro- and nitroso-compounds by tervalent phosphorus reagents. Part VII. A new synthesis of phenothiazines involving a new molecular rearrangement
作者:J. I. G. Cadogan、S. Kulik、C. Thomson、M. J. Todd
DOI:10.1039/j39700002437
日期:——
Reductive cyclisation of aryl 2-nitroaryl sulphides by triethyl phosphite provides a new synthesis of phenothiazines (yields ca. 50–85%) which is superior to that involving the thermal decomposition of aryl 2-azidoaryl sulphides (yields ca. 30%). Both reactions proceed via a novel molecular rearrangement whereby, for example, 4-chlorophenyl 2-nitrophenyl sulphide gives 3-chlorophenothiazine, whereas 4
Synthesis of Diaryl Ethers, Diaryl Thioethers, and Diarylamines Mediated by Potassium Fluoride−Alumina and 18-Crown-6: Expansion of Scope and Utility<sup>1</sup>
作者:J. Scott Sawyer、Elisabeth A. Schmittling、Jayne A. Palkowitz、William J. Smith
DOI:10.1021/jo980800g
日期:1998.9.1
An efficient alternative to the Ullmann ether synthesis of diaryl ethers, diaryl thioethers, and diarylamines involving the SNAr addition of a phenol, thiophenol, or aniline to an appropriate aryl halide, mediated by potassium-fluoride alumina and 18-crown-6 in acetonitrile or DMSO, is described. Expansion of the reaction conditions to include DMSO as solvent has resulted in a far greater range of substitution patterns permitted on the electrophile. For example, it was found that electronically unfavorable S-chlorobenzonitrile could be condensed with 3-methoxyphenol to form the corresponding diaryl ether in 66% yield, a combination not normally amenable to Ullmann coupling. Electron-withdrawing groups present on the electrophile may be as diverse as nitro, cyano, formyl, acetyl, ester, amide, and even aryl. The method features a simple reaction procedure that provides products in generally good to excellent purified yields.
Cadogan,J.I.G. et al., Journal of the Chemical Society. Perkin transactions I, 1976, p. 1749 - 1757
作者:Cadogan,J.I.G. et al.
DOI:——
日期:——
KF/Clinoptilolite: An Efficient Promoter for the Synthesis of Thioethers
Potassium fluoride impregnated on natural zeolite as a new solid base system effectively catalyzes the coupling
of thiophenols with electron-deficient fluoro-, chloro- and bromo-arenes in DMSO. This versatile and efficient solid base
has been demonstrated to afford the corresponding desired products in good to excellent yields. This procedure provides a
convenient, efficient and practical method for the preparation of diaryl thioethers.
Neue Synthese von Lactamen der Dibenz[b,f]-1,4-thiazepin-, -oxazepin und Dibenz[b, e]-azepin-Reihe. 4. Mitteilung über siebengliedrige Heterocyclen
作者:J. Schmutz、F. Künzle、F. Hunziker、A. Bürki
DOI:10.1002/hlca.19650480212
日期:——
By intramolecular application of LEUCKART's amide synthesis using isocyanato-diphenylsulphides, -diphenyloxides and -diphenylmethanes with AlCl3 in o-dichlorobenzene a method has been found which gives in very good yields 10,11-dihydro-11-oxo-dibenz[b,f]-1,4-thiazepines (VII), -oxazepines (VIII), and 5,6-Dihydro-6-oxo-dibenz[b,e]-azepines (XI), respectively.