The kinetics and mechanism of the electrophilic substitution of heteroaromatic compounds. Part XLVII. Nitration of phenylisoxazoles

Abstract

3-Methyl-5-phenylisoxazole undergoes nitration as the conjugate acid at the para-position of the phenyl group. 5-Methyl-3-phenylisoxazole undergoes nitration as the conjugate acid at the meta-position and also as the free base at the para-position of the phenyl group. Standard rates for nitration at 25 °C and H₀–6.6 are calculated and the influence of the charged and neutral isoxazolyl substituents is discussed.