“Reported, but Still Unknown.” A Closer Look into 3,4-Bis- and 3,4,5-Tris(trifluoromethyl)pyrazoles
J. Org. Chem. , 2012, 77 (1), 47-56
Straightforward practical synthetic approaches to 3,4-bis- and 3,4,5-tris(trifluoromethyl)pyrazoles have been developed. The key step of the both syntheses is a transformation of the carboxylic group in a pyrazole core into the trifluoromethyl group by sulfur tetrafluoride. The elaborated synthetic protocols allow gram-scale preparation of the target products. The obtained compounds are comprehensively characterized by means of crystallographic analysis, determination of pKa values and fluorescence measurements.
Gerus I. I.; Mironetz R. X.; Kondratov I. S.; Bezdudny A. V.; Dmytriv Y. V.; Shishkin O. V.; Starova V. S.; Zaporozhets O. A.; Tolmachev A. A.; Mykhailiuk P. K.
J. Org. Chem. 2012, 77 (1), 47-56