| abstract |
PURPOSE: To obtain the titled compound useful as a synthetic intermediate for reducing agents or antioxidants, etc. in high yield at a low cost, by subjecting the 5-position of a benzoxazole derivative to uncleophilic substitution reaction, and opening the oxazole ring. n CONSTITUTION: A benzoxazole derivative expressed by formula I [R 1 is a group bonded through (substituted) carbon atom or a group bonded through N atom having no H; R 2 and R 3 are H or groups substitutive at the aromatic ring; X 1 is Cl or Br] is subjected to the nucleophilic substitution reaction at the 5-position thereof, preferably reacted with X 2 - or X 2 H in a solvent, e.g. xylene, at 20W 120°C to give a compound expressed by formula II. The oxazole ring thereof is then opened by hydrolysis preferably under acidic conditions to afford the aimed compound expressed by formula III (R 4 is H or -COR 1 ; X 2 is nucleophilic group). n COPYRIGHT: (C)1986,JPO&Japio |