2930-27-0Relevant academic research and scientific papers
2,4,6-triphenylpyrylium cations as derivatization reagents for sulfide ions detection in TLC
Zakrzewski, Robert,Ciesielski, Witold,Ulanowska, Agnieszka,Martinez-Manez, Ramon
experimental part, p. 1139 - 1148 (2010/03/01)
We report a study of the use of 2,4,6-triphenylpyrylium salts as derivatization reagents for the simple detection of sulfide ions in thin-layer chromatography (TLC). The principle of the presented method is based on the transformation of 2,4,6-triphenylpyrylium compounds into the parent thiopyrylium derivatives upon reaction with sulfide ions. The derivatization reaction took place in a tube or directly on the TLC plate before the developing step. As a consequence of the reaction of sulfide with the 2,4,6-triphenylpyrylium derivatives, the spots became visible as yellow or blue spots on a colorless background. Spots were stable for several hours. The detection limit is at pmol per spot level and depends on the triphenylpyrylium salt used and on the detection method. Taylor & Francis Group, LLC.
Pyrylium Compounds. 33. 2-Dialkylamino-2H-thiopyrans from 2,4,6-Triaryl-thiopyrylium Salts
Zimmermann, Thomas,Fischer, Gerhard W.
, p. 567 - 572 (2007/10/02)
2,4,6-Triaryl-thiopyrylium salts 7 react with dialkylamines in diethyl ether to give stable crystalline 2-dialkylamino-2H-thiopyrans 8, the structure of which is in accordance with their u.v., n.m.r. and mass spectra.The chemical properties of 8 parallel those of structurally analogous 2-alkoxy- and 2-dialkylamino-2H-pyrans and 2-alkoxy-2H-thiopyrans.Thus, on heating 2-dimethylamino-2,4,6-triphenyl-2H-thiopyran (8a) with methanol the corresponding 2-methoxy-2H-thiopyran 9 is formed.Nitromethane and ethyl cyanoacetate give rise to ring transformations yielding 1,3,5-triphenyl benzene (10) and 2,4,6-benzonitrile (11), respectively.From 8a electrophiles (e.g. mineral acids, methyl iodide, benzoyl chloride) regenerate the initial thiopyrylium system by taking over the dialkylamino group.
Pyrylium Compounds. 32. 2-Methoxy-2H-thiopyrans from 2,4,6-Triaryl-thiopyrylium Salts
Zimmermann, Thomas,Fischer, Gerhard W.
, p. 373 - 379 (2007/10/02)
Reaction of 2,4,6-triarylthiopyrylium salts 1 with sodium methoxide in absolute methanol yields isolable 2-methoxy-2H-thiopyrans 2, the structure of which was proved spectroscopically.Using the 2,4,6-triphenyl derivative 2a as model compound, the behaviour of the 2-methoxy-2H-thiopyran system towards some nucleophiles and electrophiles was studied.Thus, on heating with ethanol the 2-ethoxy-2H-thiopyran 3 is formed.Nitromethane and ethyl cyanoacetate react with 2a in the presence of triethylamine to give 2,4,6-triphenylbenzene (6) and 2,4,6-triphenylbenzonitrile (7), respectively.Electrophiles (e.g. mineral acids or acyl halides) regenerate from 2a the starting thiopyrylium system; the same principle underlies the formation of 2,4,6-triphenyl-thiopyrylium perchlorate (1a) and 2-methoxy-3-methyl-2,4,6-triphenyl-2H-pyran (5) from 2a and 3-methyl-2,4,6-triphenylpyrylium perchlorate (4).
