抄録
In order to examine the effect of bulky substituents on the reductive cleavage of aminoxazoles, benzyl 4-R1-5-R2-2-oxazolecarbamate (I) and 2-amino-4-R1-5-R2-oxazole (II) were synthesized by the route shown in Chart 1 and 2. The nuclear magnetic resonance (NMR) spectra of the benzene protons in oxazole derivatives were examined. In 4, 5-alkyl and 4, 5-phenyl compounds proton peaks appeared as a singlet for the phenyl group at the 5-position and as a multiplet for the phenyl group at the 4-position. The latter was considered to be due to the strong effect of the lone pair electrons on the ring nitrogen.
