5-fluoro-2,3-dihydro-1H-quinolin-4-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 5-fluoro-2,3-dihydro-1H-quinolin-4-one obtained in Reference Example 3 (64 mg) in trifluoroacetic acid (5 ml), triethylsilane (0.37 ml) was added and stirred at room temperature for 16 hours. After distilling off the solvent under reduced pressure, the residue was diluted with water, adjusted to pH 11 by addition of 1M aqueous sodium hydroxide, and extracted with diethyl ether. The organic layer was washed with brine, dried over anhydrous magnesium sulfate and then filtered to remove the desiccant, followed by distilling off the solvent under reduced pressure. The resulting residue was purified by silica gel column chromatography (eluting solvent: n-hexane:ethyl acetate=3:1). The resulting residue was diluted with chloroform, added to 1M aqueous hydrochloric acid (15 ml) and partitioned. The aqueous layer was adjusted to pH 11 by addition of 2.5M aqueous sodium hydroxide, and extracted with ethyl acetate. The organic layer was washed with brine, dried over anhydrous magnesium sulfate and then filtered to remove the desiccant, followed by distilling off the solvent under reduced pressure to give the titled compound, i.e., 5-fluoro-1,2,3,4-tetrahydroquinoline (39 mg) as a light-yellow oil. was added After distilling off the solvent under reduced pressure the residue was diluted with water adjusted to pH 11 by addition of 1M aqueous sodium hydroxide extracted with diethyl ether The organic layer was washed with brine dried over anhydrous magnesium sulfate filtered to remove the desiccant by distilling off the solvent under reduced pressure The resulting residue was purified by silica gel column chromatography (eluting solvent: n-hexane:ethyl acetate=3:1) The resulting residue was diluted with chloroform added to 1M aqueous hydrochloric acid (15 ml) partitioned The aqueous layer was adjusted to pH 11 by addition of 2.5M aqueous sodium hydroxide extracted with ethyl acetate The organic layer was washed with brine dried over anhydrous magnesium sulfate filtered to remove the desiccant by distilling off the solvent under reduced pressure