[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:18]2[C:13](=[C:14]([CH3:22])[C:15]([F:21])=[C:16]([F:20])[C:17]=2[F:19])[C:12](=[O:23])[C:11]([C:24]([O:26]CC)=[O:25])=[CH:10]1.Cl>C(O)(=O)C>[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:18]2[C:13](=[C:14]([CH3:22])[C:15]([F:21])=[C:16]([F:20])[C:17]=2[F:19])[C:12](=[O:23])[C:11]([C:24]([OH:26])=[O:25])=[CH:10]1Employing ethyl 1-(2,4-difluorophenyl)-5-methyl-6,7,8-trifluoro-1,4-dihydro-4 -oxoquinoline-3-carboxylate (4.3 g) and conc. hydrochloric acid: 90% acetic acid (1:4) (80 ml), the procedure of Reference Example 23 is repeated to give 1-(2,4-difluorophenyl)-5-methyl-6,7,8-trifluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid (2.93 g), as white powder, m.p. 221°-222° C.
불러오는 중…