Acetic Acid → 6,7-Difluoro-8-methoxy-1-(methylamino)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid

Participants

Reaction Steps

4.5 ml (0.0045 mole) of a 1N aqueous solution of sodium hydroxide were added to a solution of the whole (0.0015 mole) of the ethyl 6,7-difluoro-1-(N-formylmethylamino)-8-methoxy-1,4-dihydro-4-oxoquinoline-3-carboxylate (XVII, R10 =methyl) [prepared as described in Step (D3) above] dissolved in 10 ml of ethanol, and the mixture was stirred at room temperature for 2 hours. At the end of this time, addition of acetic acid gave rise to crystals, which were collected by filtration to give 0.35 g of 6,7-difluoro-8-methoxy-1-(methylamino)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (IIb, R10 =methyl) as a colorless powder.

Provenance & Evidence