Carbostyril, 3,4-dihydro-7-fluoro- → 7-Fluoro-1,2,3,4-tetrahydroquinoline

Temperature

60 °C

To a solution of 7-fluoro-1,2,3,4-tetrahydroquinolin-2-one (1.5 g, 9.08 mmol) in tetrahydrofuran (50 ml) was dropwise BH3 in THF (1M, 90 ml), the solution was stirred for 24 h at 60° C. The reaction mixture was cooled and then quenched by the addition of methanol (15 ml) and HCl (conc) (5 ml), then stirred for 1 h at 60° C. The reaction mixture was cooled to room temperature and adjusted to pH 12 with sodium hydroxide (4 mol/L), extracted with (3×15 ml) of ethyl acetate and the organic layers were combined and dried over anhydrous magnesium sulfate, concentrated in vacuo to give a residue, which was purified by a silica gel column chromatography with 3% ethyl acetate in petroleum ether to afford 7-fluoro-1,2,3,4-tetrahydroquinoline as a yellow solid (0.9 g, 66%).

1. temperatureThe reaction mixture was cooled
2. customquenched by the addition of methanol (15 ml) and HCl (conc) (5 ml)
3. stirringstirred for 1 h at 60° C
4. temperatureThe reaction mixture was cooled to room temperature
5. extractionextracted with (3×15 ml) of ethyl acetate
6. dry with materialdried over anhydrous magnesium sulfate
7. concentrationconcentrated in vacuo
8. customto give a residue, which
9. customwas purified by a silica gel column chromatography with 3% ethyl acetate in petroleum ether

ORD record

ord-62e49abe3e214110ab49d4652556d06d

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09073902B2