[NH2:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[C:4]([N+:9]([O-])=O)[C:3]=1[CH3:12].O.[As+3]=O.S(=O)(=O)(O)O.[OH-].[NH4+].O[CH2:24][CH:25]([CH2:27]O)O>O>[NH2:1][C:2]1[C:3]([CH3:12])=[C:4]2[C:5]([CH:24]=[CH:25][CH:27]=[N:9]2)=[C:6]([F:8])[CH:7]=1A mixture of 2-amino-4-fluoro-6-nitrotoluene (4.4 g), glycerin (7.5 g), arsenic(V) oxide hydrate (Aldrich, 54% in arsenic, 5.0 g), and concentrated sulfuric acid (35 mL) is heated to 140° C. for 4 hours. The reaction is allowed to cool to room temperature and diluted with water (300 mL). The mixture is basified with concentrated ammonium hydroxide to pH=10 and extracted with ethyl acetate (6×300 mL). The combined extracts are dried over sodium sulfate and rotary evaporated. The crude product is purified by flash chromatography on silica gel, eluting with 25% ethyl acetate/hexane to afford 7-amino-5-fluoro-8-methylquinoline as a solid.
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