Nucleophilic replacement of p-(1-chloro-2,2,2-trifluoroethyl)phenols: novel synthesis of β-trifluoromethyl-tyrosine

Three para-(1-chloro-2,2,2-trifluoroethyl)phenols 2a–c were prepared by selective α-chlorination of the corresponding alcohols 1a–c. Substitution of 2a by active methylene compound 4 proceeds smoothly in the presence of an appropriate base at room temperature, giving substituted products 5–9 in good yields. On the basis of this finding, both the important β-trifluoromethyl-tyrosine 15 and its derivatives have been successfully synthesized.