Nucleophilic substitution and ring closure reactions of 4‐chloro‐3‐nitro‐2‐quinolones

Abstract

Abstract 4‐Chloro‐3‐nitro‐2‐quinolones 3 obtained from the 4‐hydroxy quinolones 1 by nitration and chlorination, reacted with sodium azide to the 4‐azido derivatives 4 which cyclized on thermolysis to yield the furoxanes 5 . Nucleophilic substitution reactions of 3 led to the 4‐amino‐, 4‐fluoro‐ and 4‐alkoxy‐3‐nitroquinolones 7, 8 and 9 , respectively. With thiols either 4‐thio‐3‐nitro‐ 10 or 3,4‐dithioquinolones 11 were obtained depending on the basic catalyst.