- Ammonium Chloride-Promoted Rapid Synthesis of Monosubstituted Ureas under Microwave Irradiation
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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.
- Lan, Chunling Blue,Auclair, Karine
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supporting information
p. 5135 - 5146
(2021/10/19)
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- A new convenient synthetic method and preliminary pharmacological characterization of triazinediones as prokineticin receptor antagonists
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A new efficient synthetic method to obtain prokineticin receptor antagonists based on the triazinedione scaffold is described. In this procedure the overall yield improves from 13% to about 54%, essentially for two factors: 1) N-(chlorocarbonyl) isocyanate is no more used, it represents the yield limiting step with an average yield not exceeding 30%. 2) The Mitsunobu reaction is not involved in the new synthetic scheme avoiding the use of time and solvent consuming column chromatography. All synthesized triazinediones were preliminary pharmacologically screened in vivo for their ability to reduce the Bv8-induced thermal hyperalgesia. In this assay all compounds displayed EC 50 values in the picomolar-subpicomolar range, some triazinediones containing a 4-halogen substituted benzyl group in position 5 showed the best activity. The analogues containing a 4-fluorine atom (PC-7) and a 4-bromobenzyl group (PC-25) resulted 10 times more potent than the reference PC-1 that bears a 4-ethylbenzyl group. While the 4-trifluoromethylbenzyl substituted analog (PC-27) was 100 times more potent as compared to PC1.
- Congiu, Cenzo,Onnis, Valentina,Deplano, Alessandro,Salvadori, Severo,Marconi, Veronica,Maftei, Daniela,Negri, Lucia,Lattanzi, Roberta,Balboni, Gianfranco
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p. 334 - 340
(2014/06/09)
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- Compounds
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The present disclosure relates to compounds of formula (II): pharmaceutical compositions comprising same and use of the compounds and compositions for the treatment of microbial infection, particularly Methicillin-resistant Staphylococcus aureus (MRSA) in
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