Water → 1-Cyclopropyl-8-ethinyl-6,7-difluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid

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Reaction Steps

10.3 g of ethyl 1-cyclopropyl-8-ethinyl-6,7-difluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylate are refluxed for 4 hours in a mixture of 100 ml of glacial acetic acid, 8 ml of water and 3 ml of concentrated sulphuric acid. After cooling to room temperature, the solid is filtered off with suction, washed with water and dried. In this way, 5.7 g of 1-cyclopropyl-8-ethinyl-6,7-difluoro-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid (62% of theory) are obtained.

Provenance & Evidence