Heteroaromatic reactivity. Part III. The kinetics of nitration of cinnoline and 2-methylcinnolinium perchlorate

Abstract

By comparison with the behaviour of 2-methylcinnolinium, 2-methylisoquinolinium, and isoquinolinium cations, it has been shown that, at 80° and in the acidity range 76·14–82·9 % sulphuric acid, cinnoline is nitrated as its cation. It and its quaternary derivative give nearly equal proportions of 5- and 8-nitro-compounds. The unprotonated N-1 in cinnolinium and 2-methylcinnolinium cations deactivates these systems by a factor of 2 × 10² to attack by the nitronium ion, and C-5 is influenced more than C-8.