341-27-5Relevant articles and documents
Ferguson et al.
, p. 5315 (1950)
Fluorophenols and (trifluoromethyl)phenols as substrates of site-selective metalation reactions: To protect or not to protect
Marzi, Elena,Mongin, Florence,Spitaleri, Andrea,Schlosser, Manfred
, p. 2911 - 2915 (2007/10/03)
O-Methoxymethyl (MOM) protected fluorophenols can be cleanly metalated and subsequently be submitted to site-selective electrophilic substitution. The 2- and 4-isomers exhibit ambivalent reactivity: deprotonation occurs at the position adjacent to the oxygen when butyllithium is employed whereas the position adjacent to the fluorine is attacked by the superbasic mixture of butyllithium and potassium tert-butoxide (LIC-KOR). The MOM-protected (trifluoromethyl)-phenols react exclusively at oxygen-neighboring positions. The meta isomer provides another example of optional site selectivity, undergoing hydrogen/metal exchange at the 2-position with the LIC-KOR reagent and at the 6-position with sec-butyllithium. Unprotected (trifluoromethyl)phenols can also be ortho-metalated after O-deprotonation, although the products are formed in only moderate yields.
An improved method for the synthesis of 3-fluorosalicylic acid with application to the synthesis of 3-(Trifluoromethyl)salicylic acid
Micklatcher, Mark L.,Cushman, Mark
, p. 1878 - 1880 (2007/10/03)
An improved method for the synthesis of 3-fluorosalicylic acid is described. A positional protective group strategy allows formylation selectively at the ortho position of 4-bromo-2-fluorophenol. Oxidation of the resulting salicylaldehyde to the salicylic acid, followed by debromination, affords 3-fluorosalicylic acid. The method has also been applied to the synthesis of 3-(trifluoromethyl)salicylic acid.