BrC[C:3]1[CH:11]=[CH:10][C:6]([C:7]([OH:9])=[O:8])=[CH:5][CH:4]=1.Br[CH2:13]C1C=CC(C(OC(C)(C)C)=O)=CC=1.CC(=C)C.N.[F-:32].C([N+](CCCC)(CCCC)CCCC)CCC>S(=O)(=O)(O)O.C(#N)C>[F:32][CH2:13][C:5]1[C:6]([C:7]([OH:9])=[O:8])=[CH:10][CH:11]=[CH:3][CH:4]=14-Bromomethylbenzoic acid was converted to t-butyl 4-bromomethylbenzoate using isobutylene in sulfuric acid [16], in 50% yield. The product, an oil, had the following NMR spectrum in CDCl3 : 6 7.96 and 7.43 (each d, 2H, J=8Hz), 4.50 (s, 2H), 1.59 (s, 9H, t-Bu). The chemical ionization mass spectrum (NH3) showed peaks at 211 (m+1), 228. The bromomethyl compound was fluorinated as above using tetrabutylammonium fluoride in acetonitrile, in 90% yield. NMR spectrum in CDCl3 : 6 8.01 and 7.41 (each d, 2H, J-8Hz), 5.44 (d, 2H, J=47Hz), 1.60 (s, 9H, t-Bu). The t-butyl ester was removed quantitatively upon 10 min exposure to neat trifluoroacetic acid. The product, α-fluorotoluic acid, was obtained as a white solid, melting at 178°-181°. The chemical ionization mass spectrum (NH3) showed a peak at 172=m+1+17). NMR spectrum in CDCl3 : δ 8.12 and 7.47 (each d, 2H, J=8Hz), 5.47 (d, 2H, J=47Hz).
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