Nucleophilic aromatic substitution with the anion of 3,5-disubstituted isoxazole-4-carboxylic acids

The preparation of the anion of a series of protected 3,5-disubstituted 4-isoxazolecarboxylic acids and the resulting addition of the anion to 9-chloroacridine is described. The addition-elimination reaction proceeds to give the expected acridinylmethylisoxazoles and has been justified based on calculated molecular mechanics energies and solvent effects.