New synthesis of caffeine methiodide and its homolog

Иванов, Э. И.; Kalayanov, G. D.; Yaroshchenko, I. M.; Stepanov, D. E.

doi:10.1007/bf00481539

Cited by 5 publications

(7 citation statements)

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“…The generation of the 1,3,7,9-tetramethylxanthinium salt was attempted by reaction of methyl iodide with caffeine in refluxing DMF [14]. However, even heating the mixture for 24 h in a closed vessel only resulted in a 1:1-mixture of the desired product and caffeine.…”

Section: Resultsmentioning

confidence: 99%

Purine-based carbenes at rhodium and iridium

Schütz

Herrmann²

2004

Journal of Organometallic Chemistry

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Section: Resultsmentioning

confidence: 99%

Purine-based carbenes at rhodium and iridium

Schütz

Herrmann²

2004

Journal of Organometallic Chemistry

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“…Cannon and Youngs et al82 reported the first series of silver(I) xanthine complexes with potential as a new class of antibiotics, especially for the treatment of lung infections seen in cystic fibrosis patients. A water‐soluble iodide salt of 1,3,7,9‐tetramethylxanthine (methylated caffeine) was prepared by treatment of caffeine with excess methyl iodide in dimethylformamide at high temperature 83. The NHC‐silver(I) acetate complex 107 based on caffeine iodide was prepared in two different ways, as shown in Scheme .…”

Section: Silver Complexes Of Miscellaneous Nhcsmentioning

confidence: 99%

Biologically Relevant Silver(I)–N‐Heterocyclic Carbene Complexes: Synthesis, Structure, Intramolecular Interactions, and Applications

et al. 2013

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N-Heterocyclic carbenes (NHCs) complexed with silver represent new, broad-spectrum antimicrobial and anticancer agents, normally with low toxicity profiles, and they provide a range of versatile structures for targeted biological applications. Most of these complexes have shown higher cytotoxicity than cisplatin, a potent anticancer drug. This study reviews the design, synthesis, structural characterization, and biological applications of silver complexes derived from both functionalized and nonfunctionalized NHC ligands. Specifically, silver complexes of functionalized and nonfunctionalized imidazole-and benzimidazole-based NHC systems employed in antimicrobial and anticancer applications are [a] www.eurjic.org MICROREVIEW with azolium salts at ambient/high temperature. Finally, the third method involves treatment of silver salts with azolium salts under basic phase-transfer conditions. [11][12][13] The use of Ag 2 O has made the synthesis of silver(I)-NHC complexes much easier and more convenient. In recent years, numerous silver-NHC complexes have been designed and synthesized according to the second method, mainly for antibacterial and anticancer activities. In 2007, Youngs et al. [14] reviewed the synthesis, characterization, and applications of silver(I)-NHC complexes for antibiotic applications. The present review on a similar topic provides a timely and critical overview of the field from the point of view of synthetic and biomedical applications, through comprehensive accounts of different methods for the synthesis of silver(I)-NHC complexes that have appeared in the literature, together with their reactivities and stabilities, since the aforementioned review. The reviews by Youngs et al. [15] and Morel and Gautier et al. [16] in 2009 focused on the applications only of imidazole-based complexes, particularly as anticancer agents.Silver-NHCs are also potent antibacterial agents and efficient candidates in the preparation of other transition metal-NHC complexes by transmetallation. Here we report recent developments in the synthesis, structures, and biological applications of silver(I) complexes of functionalized, nonfunctionalized, and nanoparticle-supported NHCs derived from both imidazole and non-imidazole cores. Several crystallographic and spectroscopic data for complexes re-Srinivasa Budagumpi was born in Karnataka, India in 1983. He received his M.Sc. in inorganic chemistry from Gulbarga University, Gulbarga, India, in 2005. Later he obtained his Ph.D. from Karnatak University, Dharwad, India, under the guidance of Prof. Vidyanand K. Revankar in 2010. During his doctoral studies he worked on the bimetallic transitionmetal chemistry of ligands having heterocyclic diazine bridging modules. Subsequently, from 2010-2012, he completed postdoctoral assignments with Prof. Il Kim and Dr. Rosenani A. Haque at Pusan National University, Busan, Republic of Korea, and Universiti Sains Malaysia, Penang, Malaysia, respectively. During his tenure in the Haque laboratory he worked on the synthesis of group XII ...

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“…Quaternization at the 9-position of xanthines including caffeine and its derivatives typically requires forcing conditions (high temperature and pressure), long reaction times and a large excess of alkyl halide. In the case of N 9-methylation of xanthines, typically, 20 equivalents of methyl iodide are used and reactions are carried out in refluxing DMF or in a closed vessel for up to 20 h [ 19 , 28 , 35 , 45 ]. Trimethyloxonium tetrafluoroborate has also be used by some groups for N -methylation of xanthines [ 17 , 33 ].…”

Section: Resultsmentioning

confidence: 99%

Facile N9-Alkylation of Xanthine Derivatives and Their Use as Precursors for N-Heterocyclic Carbene Complexes

et al. 2021

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The xanthine-derivatives 1,3,7-trimethylxanthine, 1,3-dimethyl-7-benzylxanthine and 1,3-dimethyl-7-(4-chlorobenzyl)xanthine are readily ethylated at N9 using the cheap alkylating agents ethyl tosylate or diethyl sulfate. The resulting xanthinium tosylate or ethyl sulfate salts can be converted into the corresponding PF6- and chloride salts. The reaction of these xanthinium salts with silver(I) oxide results in the formation of different silver(I) carbene-complexes. In the presence of ammonia, ammine complexes [Ag(NHC)(NH3)]PF6 are formed, whilst with Et2NH, the bis(carbene) salts [Ag(NHC)2]PF6 were isolated. Using the xanthinium chloride salts neutral silver(I) carbenes [Ag(NHC)Cl] were prepared. These silver complexes were used in a variety of transmetallation reactions to give the corresponding gold(I), ruthenium(II) as well as rhodium(I) and rhodium(III) complexes. The compounds were characterized by various spectroscopic methods as well as X-ray diffraction.

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New synthesis of caffeine methiodide and its homolog

Cited by 5 publications

References 0 publications

Purine-based carbenes at rhodium and iridium

Purine-based carbenes at rhodium and iridium

Biologically Relevant Silver(I)–N‐Heterocyclic Carbene Complexes: Synthesis, Structure, Intramolecular Interactions, and Applications

Facile N9-Alkylation of Xanthine Derivatives and Their Use as Precursors for N-Heterocyclic Carbene Complexes

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