ORGANIC AZIDES IN HETEROCYCLIC SYNTHESIS .15. NUCLEOPHILIC-SUBSTITUTION AND RING-CLOSURE REACTIONS OF 4-CHLORO-3-NITRO-2-QUINOLONES

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.