5962-13-0Relevant academic research and scientific papers
Ammonium Chloride-Promoted Rapid Synthesis of Monosubstituted Ureas under Microwave Irradiation
Lan, Chunling Blue,Auclair, Karine
supporting information, p. 5135 - 5146 (2021/10/19)
Monosubstituted ureas are important scaffolds in organic chemistry. They appear in various biologically active compounds and serve as versatile precursors in synthesis. Monosubstituted ureas were originally prepared using toxic and hazardous phosgene equivalents. Modern methods include transamidation of urea and nucleophilic addition to cyanate salts, both of which suffer from a narrow substrate scope due to the need for a strong acid and prolonged reaction times. We hereby report that ammonium chloride can promote the reaction between amines and potassium cyanate to generate monosubstituted ureas in water. This method proceeds rapidly under microwave irradiation and tolerates a broad range of functional groups. Unlike previous strategies, it is compatible with other nucleophiles, acid-labile moieties, and most of the common protecting groups. The products precipitate out of solution, allowing facile isolation without column chromatography.
Iron-catalyzed reaction of urea with alcohols and amines: A safe alternative for the synthesis of primary carbamates
Pe?a-López, Miguel,Neumann, Helfried,Beller, Matthias
, p. 2233 - 2238 (2017/07/25)
A general study of the iron-catalyzed reaction of urea with nucleophiles is here presented. The carbamoylation of alcohols allows for the synthesis of N-unsubstituted (primary) carbamates, including present drugs (Felbamate and Meprobamat, without the necessity to apply phosgene and related derivatives. Using amines as nucleophiles gave rise to the respective mono-and disubstituted ureas via selective transamidation reaction. These atom-economical transformations provide a direct and selective access to valuable compounds from cheap and readily available urea using a simple Lewis-acidic iron(Icatalyst.
Synthesis and pharmacological evaluation of novel 1- and 8-substituted-3-furfuryl xanthines as adenosine receptor antagonists
Balo, Maria Carmen,Brea, Jose,Caamano, Olga,Fernandez, Franco,Garcia-Mera, Xerardo,Lopez, Carmen,Loza, Maria Isabel,Nieto, Maria Isabel,Rodriguez-Borges, Jose Enrique
scheme or table, p. 6755 - 6760 (2009/12/26)
The synthesis of an important set of 3-furfurylxanthine derivatives is described. Binding affinities were determined for rat A1 and human A2A, A2B and A3 receptors. Several of the 3-furfuryl-7-methylxanthine der
Xanthine modulators of metabolism of cellular P-450
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, (2008/06/13)
A new class of xanthine compounds, variously substituted at the 1, 3, 7 and 8 positions, is characterized by an ability to modulate the activity of key enzymes involved in drug metabolism. These compounds generally are useful in affecting drug metabolism and, particularly, in extending the circulating half-life of compounds that are metabolized via P-450-mediated pathways.
