RESUMO
The two isotopomers of teriflunomide were synthesized starting from isotopically stable-labeled stocks of [13 C]potassium cyanide and [1-13 C]ethyl bromoacetate. The two 13 C-labeled compounds 1a, b were applied in several NMR studies to study the E/Z ratio in different matrices. In a solution, such as dimethyl sulfoxide (DMSO), a dynamic equilibrium between E/Z-isomers (ratio of 8:92) was determined by initial 13 C-carbon NMR experiments. To get insights into the E/Z ratio of teriflunomide under in vivo conditions, advanced heteronuclear NMR (heteronuclear Overhauser effect spectroscopy [HOESY]) in D2 O and mixtures of D2 O/plasma were performed. Whereas NMR experiments in mixtures of water and plasma failed owing to extreme line broadening, NMR spectra in water at pH 7.4 showed only the Z-isomer.
Assuntos
Crotonatos/síntese química , Hidroxibutiratos/síntese química , Marcação por Isótopo/métodos , Nitrilas/síntese química , Toluidinas/síntese química , Acetatos/química , Isótopos de Carbono/química , Hidrocarbonetos Bromados/química , Isomerismo , Espectroscopia de Ressonância Magnética/métodos , Cianeto de Potássio/químicaRESUMO
1,6-Dideoxygalactostatin, the mirror image of 1-deoxy-L-fuconojirimycin, was efficiently prepared from 2,3-O-isopropylidene-L-lyxonolactone in four steps and evaluated as a glycosidase inhibitor.