The Study of Nitrogen-Containing Heterocyclic Compounds. Part XI. Regiospecific Nitration of Quinoline and Isoquinoline throuth the Reissert Compounds.

Abstract

Regiospecific nitration of quinoline and isoquinoline was achieved via the Reissret compounds by treatment with acetyl nitrate. Nitration of 1-benzoyl-2-cyanoquinoline (3) afforded the 3-nitro derivative, which was converted to 3-nitroquinoline by hydrolysis with concentrated HCl. Meanwhile, 2-benzoyl-1-cyano-1, 2-dihydroisoquinoline (4) was converted ultimately into 4-nitroisoquinoline-1-carboxylic acid (10) via 4-nitro-1-cyanoisoquinoline by the same procedure. A novel method for introducing a nitro group at the β-position of a heterocyclic moiety has thus been developed. Crystal structure determinations and molecular orbital calculations of the Reissert compounds, are consistent with the regiospecific nitration.