Product use：Basic raw materials, organic intermediates, pharmaceutical intermediates
The synthetic route is as follows:
Reactants are commercially availlable.
ZHU, Jiuxiang, WO2015/78374, A1, (2015) To a solution of 1- (tert-butoxycarbonyl) -4-fluoropiperidine-4-carboxylic acid (5.00 g, 20.20 mmol) in tetrahydrofuran (100 mL) was added a solution of borane tetrahydrofuran complex (30.3 mL, 30.30 mmol, 1.0 M solution in tetrahydrofuran) . The reaction mixture was refluxed for 16 hours, and then another 24 mL of borane tetrahydrofuran complex was added and continued to reflux for another 16 hou rs. After cooling to ambient temperature the reaction mixture poured onto ice-cold water (50 mL) and saturated ammonium chloride (100 mL) , and extracted with ethyl acetate (3 x 100 mL) , dried over a nhydrous sodium sulfate and filtered. The filtrate was concentrated to afford the title compound (4.60 g, 98) . Which was used in the next step without further purification: MS (ES+) m/z 234.1 (M +1) .