Water → 5-amino-7-fluoro-1-[2-(S)-fluoro-1-(R)-cyclopropyl]-1,4-dihydro-8-methyl-4-oxoquinoline-3-Carboxylic Acid

Participants

Reaction Conditions

Reaction Steps

Ethyl 5-amino-7-fluoro-1-[2-(S)-fluoro-1-(R)-cyclopropyl]-1,4-dihydro-8-methyl-4-oxoquinoline-3-carboxylate (735 mg, 2.28 mmol) was dissolved in a 1:1 mixed solution (8 ml) of acetic acid:water, and after adding concentrated sulfuric acid (90 μl) thereto, it was stirred for 4 hours in an oil bath of 120° C. After cooling the reaction solution with ice, water (20 ml) was poured therein, and the mixed reaction solution was stirred at room temperature for 2 hours. The precipitated crystals were filtered out, washed with excess water, a small amount of cold ethanol and excess diethyl ether in that order, and then dried under a reduced pressure at 80° C. for 17 hours. 552 mg (82%) of the title compound was thereby obtained in the form of yellow crystals.

Provenance & Evidence