Water → HCID 86689080, compound

Participants

Reaction Steps

6-[3-(4-Fluoro-phenyl)-5-methyl-isoxazol-4-ylmethoxy]-nicotinic acid (23.0 g, 70.1 mmol) and 1,1-carbonyldiimidazole (15.3 g, 94.6 mol, 1.35 eq.) were dissolved in THF (120 mL) and the resulting solution was stirred for one hour at room temperature. This solution was then added to a suspension of thiomorpholine-1,1-dioxide HCl (16.9 g, 98.5 mmol), DMAP (400 mg, 3.27 mmol) and triethylamine (9.78 g, 96.7 mmol) in THF (120 mL). The resulting mixture was heated to reflux temperature and subsequently stirred at this temperature for 50 hours. The mixture was cooled to room temperature and then treated within one hour with water (300 mL). From the resulting suspension THF was distilled off under reduced pressure and with a jacket temperature of 60° C. and continuously replaced by ethanol (426 g) at constant volume. The suspension was cooled to room temperature and stirred for 2 hours. The crystals were filtered off, washed with a mixture of ethanol (100 mL) and water (100 mL) and subsequently dried at 55° C./<25 mbar until constant weight to afford 28.9 g (92%) of Form B as a colorless solid with purity of 99.7% (area) as measured by HPLC.

Provenance & Evidence