Patent ID: 6590101
Filing Date: 2003-07-08
Classification: C07D

Abstract:
A process for the preparation of fluoroquinolonecarboxylic acids by hydrolysis of the corresponding C1-C4-alkyl esters comprising(a) mixing water, acetic acid, and sulfuric acid with a C1-C4-alkyl fluoroquinolonecarboxylate, wherein less than 30 g of sulfuric acid per 1 mol of C1-C4-alkyl fluoroquinolonecarboxylate are employed, (b) heating the resultant reaction mixture at reflux for 0.5 to 8 hours, (c) distilling off a mixture of acetic acid, C1-C4-alkyl acetate, C1-C4-alkyl alcohol, and optionally water, and (d) isolating the resultant fluoroquinolonecarboxylic acid.