264601-17-4Relevant academic research and scientific papers
An exploratory and mechanistic study of the defluorination of an (aminofluorophenyl)oxazolidinone: SN1(Ar*) vs. S R+N1(Ar*) mechanism
Fasani, Elisa,Tilocca, Fedele,Protti, Stefano,Merli, Daniele,Albini, Angelo
experimental part, p. 4634 - 4642 (2009/03/12)
The morpholinofluorophenyloxazolidinone 1 (the antibacterial drug linezolid) is found to undergo reductive defluorination upon irradiation in water (Φ 0.33), in some of the products accompanied by the simultaneous oxidative degradation of the morpholine side chain. In the presence of chloride, iodide and pyrrole, the fluorine is substituted by these groups (with pyrrole, in position 2). The defluorination is less efficient in methanol and mainly leads to reduction (Φ 0.053). These data can be accommodated through two different mechanisms, viz. either C-F bond heterolysis to give a phenyl cation [SN1(Ar*)], or ionization to give a radical cation [S R+N1(Ar*)]. Steady-state and time resolved data have been gathered for clarifying this issue. It is found that, indeed, ionization of 1 is efficient and proceeds from the singlet, but leads to no irreversible change. On the contrary, triplet 31 (lifetime 0.5 μs in MeOH, 0.1 μs in water) fragments and gives the corresponding triplet phenyl cation. The last intermediate explains well the observed hydrogen abstraction both inter- (from the solvent, when this is reducing) and intramolecularly (from the morpholine group), as well as addition to a charged anion or to a neutral π nucleophile such as pyrrole. The rationalization is supported by the study of some related molecules. Thus, the only photochemical reaction from the non fluorinated analogue of linezolid (that ionizes just as 1) is an inefficient degradation of the morpholine chain (Φ 0.001), while a simple model such as N-(2-fluorophenyl)morpholine undergoes photosolvolysis in water and is not trapped by pyrrole.
Discovery of the novel antithrombotic agent 5-chloro-N-({(5S)-2-oxo-3-[4- (3-oxomorpholin-4-yl)phenyl]-1,3-oxazolidin-5-yl}methyl)thiophene-2-carboxamide (BAY 59-7939): An oral, direct factor Xa inhibitor
Roehrig, Susanne,Straub, Alexander,Pohlmann, Jens,Lampe, Thomas,Pernerstorfer, Josef,Schlemmer, Karl-Heinz,Reinemer, Peter,Perzborn, Elisabeth
, p. 5900 - 5908 (2007/10/03)
Despite recent progress in antithrombotic therapy, there is still an unmet medical need for safe and orally available anticoagulants. The coagulation enzyme Factor Xa (FXa) is a particularly promising target, and recent efforts in this field have focused on the identification of small-molecule inhibitors with good oral bioavailability. We identified oxazolidinone derivatives as a new class of potent FXa inhibitors. Lead optimization led to the discovery of BAY 59-7939 (5), a highly potent and selective, direct FXa inhibitor with excellent in vivo antithrombotic activity. The X-ray crystal structure of 5 in complex with human FXa clarified the binding mode and the stringent requirements for high affinity. The interaction of the neutral ligand chlorothiophene in the S1 subsite allows for the combination of good oral bioavailability and high potency for nonbasic 5. Compound 5 is currently under clinical development for the prevention and treatment of thromboembolic diseases.
