Oxalyl chloride (0.063 ml) was added to a stirred suspension of (R)-(+)-2-hydroxy-2-methyl-3,3,3-trifluoropropanoic acid (Method 9) (0.106 g) in dichloromethane (2 ml) containing DMF (1 drop). The mixture was stirred at ambient temperature for 90 minutes and was then added to a solution of 2-chloro-4-phenylthioaniline (Method 11) (0.143 g) in dichloromethane (4 ml) and stirred a further 3 hours. Ethyl acetate (30 ml) was added and the mixture was washed with water (2×30 ml) and brine then dried. Volatile material was removed by evaporation and the residue was purified by chromatography on a silica gel Mega Bond Elut column eluting with 15% ethyl acetate/hexane to give the title compound (0.153 g) as a gum. NMR: 1.57 (s, 3H), 7.26-7.41 (m, 6H), 7.44 (d, 1H), 7.82 (s, 1H), 7.95 (d, 1H), 9.74 (s, 1H); MS: 374 (M−H)−.
