Heteroaromatic reactivity. Part VI. Kinetics and products of the nitration of 4-hydroxyquinoline, 1-methyl-4-quinolone, 4-methoxyquinoline, and 4-hydroxycinnoline in sulphuric acid

Abstract

The rates and products of nitration of the title compounds have been measured. The quinoline derivatives react as their conjugate acids, but with 4-hydroxycinnoline the free base may be involved to some extent. Surprisingly large proportions of 1-methyl-3-nitro-4-quinolone are formed from 1-methyl-4-quinolone. The 4-substituents in the cations from 4-hydroxy- and 4-methoxy-quinoline activate C(6) by factors of 3·3 × 10³ and 1·6 × 10³, and C(8) by factors of 29·5 and 23, respectively, the large effect at C(6) being noteworthy.