Adamantylation of N-aryl and N-arylalkyl acetamides in trifluoroacetic acid.

Alkylation of N-aryl and N-arylalkyl acetamides with hydroxy adamantane derivatives in trifluoroacetic acid was studied. The differentiating effect of trifluoroacetic acid on the regio-selectivity of adamantylation of o-alkyl-substituted acetanilides was established, leading to energetically more stable products of para-substitution with respect to the alkyl group (the content of para-alkyl isomers is 93–94%). This enabled the synthesis of adamantylaminoarenes in 83–99% yields and with 95–99% purity. [ABSTRACT FROM AUTHOR]