Use of hexafluoroacetone and fluorine nuclear magnetic resonance to characterize alcohols and other active hydrogen compounds

P-fluorobenzoyl chloride for characterization of active hydrogen functional groups by fluorine-19 nuclear magnetic resonance spectrometry

“…The size of the ortho substituent can dramatically increase this deshielding effect. Similar de- shielding results were found by Ho and Leader where bulky ortho groups generally exhibit a deshielding of the 19F chemical shifts for ortho-substituted phenol adducts formed by hexafluoroacetone (8)(9)(10)(11). This was also found for p-fluorobenzoate phenol derivatives (e.g., o-cresol, -37.20 ppm, compared with 2-ferf-butyl-4-methylphenol, -35.01 ppm).…”

“…Leader (8) has suggested the use of hexafluoroacetone for the characterization of various functional groups. The reagent reacts with active hydrogen groups as indicated in the scheme The reagent has been shown to react with alcohols, amines, mercaptans, and other compounds with active hydrogens (8)(9)(10)(11)(12)(13). For primary alcohols and nonhindered secondary alcohols the equilibrium indicated in eq 2 usually shifts far to the right.…”

Trifluoroacetyl chloride for characterization of organic functional groups by fluorine-19 nuclear magnetic resonance spectrometry

“…Another 19F reagent, hexafluoroacetone, was suggested by Leader (6) for the characterization of various functional groups. The general adduct formation of hexafluoroacetone with active hydrogen compounds is indicated below This reagent has been suggested for characterization of alcohols, amines, mercaptans and other active hydrogen containing compounds (6)(7)(8)(9)(10)(11). Preparation of the adducts is easily accomplished in situ by bubbling the reagent gas (hexafluoroacetone) into a solution of the sample and solvent.…”

Hexafluoroacetone: An Appealing Key Player in Organic Chemistry

“…3 In analytical studies, HFA can be used as a reagent in 19 F NMR spectroscopy of compounds comprising active hydrogens. 4 Preparation HFA can be prepared from perfluoropropene and elemental sulfur in the presence of KF. 5 It can be obtained in the laboratory by drop-wise addition of its commercially available trihydrate to concentrated sulfuric acid at 80-100 °C.…”