Thermal rearrangement of 2-bromooxazolines to 2-bromoisocyanates.
A unprecedented thermally induced rearrangement of 2-bromo-4-substituted oxazolines into 2-bromoisocyanates with high selectivity has been observed. Isolated yields of 85-90% were obtained with 2-bromo-4-phenyloxazoline, 2-bromo-4-isopropyloxazoline, or 2-bromo-4,4-dimethyloxazoline. In addition, chiral aziridinecarboxamides or 2-aminooxazolines could be selectively obtained from the corresponding 2-bromo isocyanate depending on reaction conditions.