On the regioselectivity in the reaction of aliphatic ketones and aromatic nitriles. Regiospecific synthesis of alkylarylpyrimidines

The reaction of aliphatic ketones with aliphatic or aromatic nitriles in the presence of trifluoromethanesulfonic anhydride has been shown to be a very useful method for the preparation of alkyl- and aryl-pirimidines. The reaction shows a high degree of regioselectivity that depends on the characteristics of the residues attached at the carbonyl group. The results from different branched symmetric and asymmetric ketones are shown. Molecular mechanics calculations permit an explanation and predict the results obtained. Regiospecific synthesis of alkyl aryl pyrimidines is described.