Lm. Yagupolskii et al., THE INTERACTION OF 2,6-DIMETHYL-3,5-DICARBOXY-4-PHENYLPYRIDINE WITH SF4 IN HF SOLUTION, Journal of fluorine chemistry, 67(1), 1994, pp. 5-6
Reaction of 2,6-dimethyl-3,5-dicarboxy-4-phenylpyridine with sulphur t
etrafluoride in HF solution leads to thyl-4-trifluoromethyl-9,9'-diflu
oro-2-azafluorene as the main product accompanied by a minor yield of
imethyl-3,5-bis(trifluoromethyl)-4-phenylpyridine.