Studies on the Doebner-Miller, Skraup, and Related Reactions. II. Preparation and Cyclization of 4-(2'-Nitroanilino)-3-methylbutan-2-one

Abstract

The intermediate adduct (e.g. III) formed in Skraup and Doebner-Miller reactions has the nature of a Mannich base. It has now been prepared from o-nitroaniline, formaldehyde, and methyl ethyl ketone by the Mannich reaction. It has been cyclized to 3,4-dimethyl-8-nitroquinoline under acidic oxidizing conditions; but it is not cyclized by neutral oxidants, nor by non-oxidizing acids or Lewis acids.