efficient synthesis from p-substituted acetophenones. Alkylation of heterocycles 6–10 in the form of their potassium or tetraalkylammonium salts 11–15 affords N-alkoxy-4-arylthiazole-2(3H)-thiones 16–20 in good to satisfactory yields. The hitherto unknown thiones 16–20 have been subjected to a detailed structural investigation (NMR spectroscopy and X-ray crystallography) and furthermore to a mechanistic
Towards Improved Alkoxyl Radical Precursors - The Synthesis of <i>N</i>-Alkoxy-4-(<i>p</i>-chlorophenyl)thiazole-2(3<i>H</i>)-thiones
作者:Jens Hartung、Michaela Schwarz
DOI:10.1055/s-1997-5754
日期:1997.7
4-(p-Chlorophenyl)-3-hydroxythiazole-2(3H)-thione (3) can be prepared in good yields and in useful quantities from p-chloro acetophenone (1). 0-Alkylation of the cyclic thiohydroxamic acid 3 via the respective potassium or the tetraethyl ammonium salts affords the esters 4. A slightly modified procedure allows the conversion of the acid 3 to the mixed anhydrides 5. The esters 4 and the anhydrides 5 are colorless to yellowish crystalline compounds which show a good shelf life. Visible light photolysis of the N-alkoxy derivatives 4e-g and reactive hydrogen donors affords substituted tetrahydrofurans 7 or tetrahydropyrans 8 via an alkoxyl radical pathway.
Balancing Conjugational Stabilization and Torsional Strain. The Solid-State Structure of a 2-Thioalkyl-Substituted Pyridine N-Oxide
作者:J. Hartung、I. Svoboda、H. Fuess
DOI:10.1107/s0108270196007019
日期:1996.11.15
The solid-state geometry of 2-(1-phenyl-4-penten-1-yl-thio)pyridine N-oxide, C16H17NOS, provides an insight into the spatial arrangement of the 2-thioalkyl side chain. The N2-C7-S8 bond angle [112.0(2)degrees] shows a significant and unprecedented distortion from the expected value of 120 degrees towards the pyridine N-oxide O atom. The substituents of the thioether are arranged to allow conjugational interaction of the lone pairs on sulfur and the heteroaromatic nucleus on one side, and a minimization of conformational strain between the pyridyl and the alkenyl groups on the other side.
Hartung, Jens; Hiller, Margit; Schmidt, Philipp, Chemistry - A European Journal, 1996, vol. 2, # 8, p. 1014 - 1023