[CH3:1][N:2]([CH3:17])[C:3]([O:5][C:6]1[CH:7]=[N:8][CH:9]=[CH:10][C:11]=1[N:12]=CN(C)C)=[O:4].[F:18][C:19]([F:24])([F:23])[C:20]([OH:22])=[O:21]>O>[F:18][C:19]([F:24])([F:23])[C:20]([OH:22])=[O:21].[CH3:1][N:2]([CH3:17])[C:3](=[O:4])[OH:5].[NH2:12][C:11]1[CH:10]=[CH:9][N:8]=[CH:7][C:6]=1[OH:5]A mixture prepared from 4-[[(dimethylamino)methylene]amino]-3-pyridinol N,N-dimethylcarbamate (7.4 g), trifluoroacetic acid (30 mL) and water (15 mL) was refluxed for a half hour. The reaction mixture was concentrated, filtered over a pad of basic alumina (CH2Cl2, 30% ethyl acetate/CH2Cl2, ethyl acetate), recrystallized from methano/diethyl ether, and dried under high vacuum and refluxing ethanol to yield 4.97 g of microcrystals, m.p. 159°-160° C.
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