To a suspension of 6-chloro nicotinic acid (1.76 g, 11.2 mmol) in DCM (50 ml) at 0° C. was added EDC.HCl (2.93 g, 15.3 mmol), HOBt (2.34 g, 15.3 mmol) and DIPEA (7.52 ml, 40.8 mmol) and the mixture stirred for 20 min. 1-{[4-(Trifluoromethyl)phenyl]sulfonyl}piperazine (may be prepared as described in Description 1) (3.00 g, 10.2 mmol) was added and the solution allowed to warm to room temperature, then stirred overnight. The mixture was diluted with DCM (20 ml), washed with water (5×20 ml), then the organic layers dried (Na2SO4) and concentrated under vacuum to leave the crude compound. Flash chromatography (silica; 60% EtOAc in pet. ether) gave the title compound as a white solid (2.20 g).
