Hydrochloric Acid → 5-Amino-1-cyclopropyl-6,7-difluoro-8-methyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid
Reaction equation
[NH2:1][C:2]1[C:11]([F:12])=[C:10]([F:13])[C:9]([CH3:14])=[C:8]2[C:3]=1[C:4](=[O:23])[C:5]([C:18]([O:20]CC)=[O:19])=[CH:6][N:7]2[CH:15]1[CH2:17][CH2:16]1.Cl>C(O)(=O)C>[NH2:1][C:2]1[C:11]([F:12])=[C:10]([F:13])[C:9]([CH3:14])=[C:8]2[C:3]=1[C:4](=[O:23])[C:5]([C:18]([OH:20])=[O:19])=[CH:6][N:7]2[CH:15]1[CH2:17][CH2:16]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
A mixture of 14.8 g of ethyl 5-amino-1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methyl-4-oxoquinoline-3-carboxylate, 150 ml of 90% acetic acid, and 37.2 ml of conc. hydrochloric acid was heated under reflux for 2 hours. The crystals precipitated were collected by filtration and washed with water to give 11.8 g of yellow crystals. The crystals were recrystallized from N,N-dimethylformamide to give yellow crystals, m.p. 290.5° C. (decomp.).