2-amino-6-chloro-4-fluorophenol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Amino-6-chloro-4-fluorophenol (3 g) was dissolved in m-xylene (150 ml) containing propionyl chloride (2.05 g), triethylamine (2.24 g) and pyridinium p-toluenesulfonate (2.8 g). The mixture was refluxed under N2 for 4 hours, then cooled to room temperature and passed through a silica gel column eluted with a mixture of hexane and ether (5:1) to yield the title compound as a pale-brown solid (2.85 g). 1H-NMR (CDCl3, 300 MHz): 1.45(3H, t, J=7.6 Hz), 2.98(2H, q, J=7.6 Hz), 7.07(1 H, dd, J=2.3 Hz, 9.2 Hz), 7.27(1 H, dd, J=2.4 Hz, 8.1 Hz) ppm. The mixture was refluxed under N2 for 4 hours eluted with a mixture of hexane and ether (5:1)