Solvent-free synthesis of thio-alkylxanthines from alkylxanthines using microwave irradiation
An expeditious, solvent-free procedure for the conversion of the xanthine bases theophylline, 8-methyltheophylline, caffeine, and theobromine to the corresponding 6-thio and 2,6-dithio derivatives using Lawesson's reagent under microwave irradiation is proposed.
Rico-Gomez, Rodrigo,Najera, Francisco,Lopez-Romero, Juan Manuel,Ca, Pedro
Antioxidant properties of thio-caffeine derivatives: Identification of the newly synthesized 8-[(pyrrolidin-1-ylcarbonothioyl)sulfanyl]caffeine as antioxidant and highly potent cytoprotective agent
A series of nine thio-caffeine analogues were synthesized and characterised by NMR, FT-IR and MS spectroscopic methods. Molecular structures of four of them were determined using single crystal X-ray diffraction methods. The antioxidant properties of all
Reactions of 6-thiotheophylline with alkylating agents and epichlorohydrin: Isolation of S-alkylated 6-thiotheophylline and 7-(2,3-thioepoxypropyl)theophylline
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Hayashi,Suzuki,Yasuzawa,Ueno
p. 247 - 251
(2007/10/02)
Sulfidation of Selected Carboxylic and Carbonic Acid Amides with the (9-BBN)2S-Reagent
The sulfidation of eight carboxylic and carbonic acid amides (A-H) with bis(1,5-cyclooctanediylboryl) sulfide (1) is described.From the aliphatic acyclic amide A and the N-substituted lactams C-E the corresponding thiocarbonyl compounds 2a and 2c-e, resp.
Koester, Roland,Kucznierz, Ralf
p. 1081 - 1086
(2007/10/02)
A Rapid and Efficient Synthesis of Sulfur Analogues of Pyrimidine Bases
An improved procedure for thionation of some natural pyrimidine bases with tetraphosphorus decasulfide/sodium hydrogen carbonate is reported.Some substituted uracils and 2-thiouracils were converted into a series of analogues in which the oxygen at position 4 was replaced by sulfur atom.The advantage of this method of thionation over the older procedures is based on the tetraphosphorus decasulfide/sodium hydrogen carbonate mixture giving rise to excellent yields and simplified isolation of the desired pure products.
Lapucha, Andrzej R.
p. 256 - 258
(2007/10/02)
METHYLATION OF THIOURACILS AND THIOXANTHINES WITH TRIMETHYL PHOSPHATE