1-Cyclopropyl-6-fluoro-7-(4-formyl-3-methyl-1-piperazinyl)-5-methyl-4-oxo-3-formyl1,2,3,4-tetrahydroquinoline → 1-Cyclopropyl-6-fluoro-7-(4-formyl-3-methyl-1-piperazinyl)-5-methyl-3-formyl-1,4-dihydro-4oxoquinoline

Participants

Reaction Steps

1-Cyclopropyl-6-fluoro-7-(4-formyl-3-methyl-1-piperazinyl)-5-methyl-4-oxo-3-formyl-1,2,3,4-tetrahydroquinoline (4.0 g) is dissolved in methanol (150 ml) and thereto is added manganese dioxide (9.3 g), and the mixture is stirred at room temperature for 2 hours. After removing manganese dioxide by filtration with celite, the filtrate is concentrated, and the resulting residue is recrystallized from ethanol to give 1-cyclopropyl-6-fluoro-7-(4-formyl-3 -methyl-1-piperazinyl)-5-methyl-3-formyl-1,4-dihydro-4oxoquinoline (3.9 g), as pale yellow powdery crystals, m.p. 258°-260° C.

Provenance & Evidence