(2-amino-5-fluorophenyl)-(4-fluorophenyl)methanone

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 46.6 g (0.2 mole) of 2-amino-4',5-difluorobenzophenone in 1300 ml of methylene chloride was cooled to -65° C. and 26.8 g (0.2 mole) of ethyl methylthioacetate was added. The cold mixture was stirred vigorously while 23.0 g (0.2 mole) of 95% tertiary butoxy chloride was added dropwise. The mixture was stirred at -70° C. for one hour, then 23 g (0.22 mole) of triethylamine was added. The mixture was allowed to warm to room temperature and 10 ml of concentrated hydrochloric acid was added. The mixture was heated at reflux with vigorous stirring for 2 hrs. The organic phase was separated and the residue was crystallized from ethyl acetate to give 28.9 g (45%) of the titled compound as off-white crystals, m.p. 171.0°-172.5° C. was added dropwise to warm to room temperature The mixture was heated at reflux with vigorous stirring for 2 hrs The organic phase was separated the residue was crystallized from ethyl acetate