3-Fluoro-5-(trifluoromethyl)pyridine-2-carboxamide synthesis

Yield:852062-16-9 66%

Reaction Conditions:

with sulfuric acid at 105; for 2 h;

Steps:

117

Description 117; 3-Fluoro-5-trifluoromethylpyridine-2-carboxamide; Description 116 (8 g, 42 mmol) was added to stirring conc. H2SO4 (65ml) and the reaction mixture heated at 105°C for 2 hours, then cooled to room temperature and poured onto ice water. The solid which formed was collected by filtration and washed with a little water to give the title compound (5.8 g, 66%). 1H NMR (400 MHz, DMSO-d6) 7.90 (1 H, s), 8. 17 (1 H, s), 8.46 (1 H, d, J 10. 1), 8.88 (1 H, s).

References:

WO2005/47279,2005,A1 Location in patent:Page/Page column 57