Sulfuric Acid → ethyl 7,8,9-trifluoro-1-hydroxymethyl-5-oxo-5H-thiazolo[3,2-a]quinoline-4-carboxylate
Reaction equation
C([O:4][CH2:5][C:6](=O)[CH2:7][S:8][C:9]1[C:18]([C:19]([O:21][CH2:22][CH3:23])=[O:20])=[C:17]([OH:24])[C:16]2[C:11](=[C:12]([F:27])[C:13]([F:26])=[C:14]([F:25])[CH:15]=2)[N:10]=1)(=O)C.S(=O)(=O)(O)O>O>[F:25][C:14]1[CH:15]=[C:16]2[C:11](=[C:12]([F:27])[C:13]=1[F:26])[N:10]1[C:6]([CH2:5][OH:4])=[CH:7][S:8][C:9]1=[C:18]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[C:17]2=[O:24]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
Ethyl 2-(3-acetoxy-2-oxopropylthio)-6,7,8-trifluoro-4-hydroxyquinoline-3-carboxylate (3.54 g) was added to concd. sulfuric acid (35 ml) and the mixture was stirred at room temperature for 2 hours and 15 minutes. Thereto water (29 ml) was added gradually with ice-cooling and the mixture was stirred at room temperature for 26 hours, followed by addition of ice-water (400 ml). After precipitated crystal was filtered and washed with water, the resultant was recrystallized from a mixed solvent of chloroform - ethanol to give the title compound (2.38 g) as pale yellow crystals.