J. Boivin et al., TRIFLUOROMETHYL KETONES FROM CARBOXYLIC-ACIDS .2. A VERSATILE ACCESS TO TRIFLUOROMETHYLATED HETEROCYCLES, Tetrahedron, 51(9), 1995, pp. 2585-2592
Various trifluoromethylated heterocycles can be prepared in good yield
from carboxylic acid chlorides by reaction with pyridine and trifluor
oacetic anhydride followed by capture of the intermediate trifluoroacy
l ketene with suitable reagents.