1611-65-0Relevant academic research and scientific papers
Carbonyldiimidazole-mediated lossen rearrangement
Dube, Pascal,Fine Nathel, Noah F.,Vetelino, Michael,Couturier, Michel,Aboussafy, Claude Larrivee,Pichette, Simon,Jorgensen, Matthew L.,Hardink, Mark
supporting information; experimental part, p. 5622 - 5625 (2010/03/02)
[Chemical Equation Presented] Carbonyldiimidazole (CDI) was found to mediate the Lossen rearrangement of various hydroxamic acids to isocyanates. This process is experimentally simple and mild, with imidazole and CO 2 being the sole stoichiometric byproduct. Significant for large-scale application, the method avoids the use of hazardous reagents and thus represents a green alternative to standard processing conditions for the Curtius and Hofmann rearrangements.
Organosilicon synthesis of isocyanates: II. Synthesis of aliphatic, carbocyclic, and fatty-aromatic isocyanates
Lebedev,Lebedeva,Sheludyakov,Ovcharuk,Kovaleva,Ustinova
, p. 469 - 477 (2008/02/07)
Silylation of a series of aliphatic, carbocyclic, and fatty-aromatic amines gave the corresponding silyl derivatives whose yield depended on the electronic and steric structure of the substrate and the nature of the silylating agent. The yield of isocyanates obtained by phosgenation of the silyl derivatives under mild conditions decreased in going from aliphatic amines to benzylamines and rose as the length of the alkyl chain in fatty-aromatic amines extended. The most convenient procedure for the synthesis of low-boiling alkyl isocyanates was found to be based on the transformation of amines or ammonium salts into silyl or silyl silyl-carabamates, followed by pyrolysis of the latter in the presence of trichloro(phenyl)silane. Pleiades Publishing, Inc., 2006.
Development of chiral N-alkylcarbamates as new leads for potent and selective H3-receptor antagonists: Synthesis, capillary electrophoresis, and in vitro and oral in vivo activity
Sasse, Astrid,Kiec-Kononowicz, Katarzyna,Stark, Holger,Motyl, Malgorzata,Reidemeister, Sibylle,Ganellin, C. Robin,Ligneau, Xavier,Schwartz, Jean-Charles,Schunack, Walter
, p. 593 - 600 (2007/10/03)
Novel carbamates as derivatives of 3-(1H-imidazol-4-yl)propanol with an N-alkyl chain were prepared as histamine H3-receptor antagonists. Branching of the N-alkyl side chain with methyl groups led to chiral compounds which were synthesized stereospecifically by a Mitsunobu protocol adapted Gabriel synthesis. The optical purity of some of the chiral compounds was determined (ee > 95%) by capillary electrophoresis (CE). The investigated compounds showed pronounced to high antagonist activity (K(i) values of 4.1-316 nM) in a functional test for histamine H3 receptors on rat cerebral cortex synaptosomes. Similar H3-receptor antagonist activities were observed in a peripheral model on guinea pig ileum. No stereoselective discrimination for the H3 receptor for the chiral antagonists was found with the in vitro assays. All compounds were also screened for central H3-receptor antagonist activity in vivo in mice after po administration. Most compounds were potent agents of the H3-receptor-mediated enhancement of brain N(τ)- methylhistamine levels. The enantiomers of the N-2-heptylcarbamate showed a stereoselective differentiation in their pharmacological effect in vivo (ED50 of 0.39 mg/kg for the (S)-derivative vs 1.5 mg/kg for the (R)- derivative) most probably caused by differences in pharmacokinetic parameters. H1- and H2-receptor activities were determined for some of the novel carbamates, demonstrating that they have a highly selective action at the histamine H3 receptor.
