Synthesis
Step 3: L-(+)-2-cyclohexylglycine (1 g, 6.36 mmol) was added batchwise to a stirred suspension of anhydrous tetrahydrofuran (THF, 20 mL) of lithium aluminum hydride (LiAlH4, 724 mg, 19.08 mmol) at room temperature. The reaction mixture was heated to 80 °C and maintained for 4 hours. Upon completion of the reaction, the mixture was cooled to 0 °C, followed by the slow addition of water (1 mL), 1 M aqueous sodium hydroxide (NaOH) solution (1 mL) and water (3 mL) in that order to quench the reaction. The mixture was filtered and the filtrate was extracted by partitioning with dichloromethane (DCM), 1M NaOH aqueous solution and saturated sodium tartrate aqueous solution. The organic layer was separated and further washed with 1M NaOH aqueous solution. The organic layer was dried over anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure to give the crude product (S)-2-amino-2-cyclohexylethanol (500 mg) without further purification. The product molecular ion peak m/z 144 ([M+H]+) was measured by liquid chromatography-mass spectrometry (LCMS, ESI) analysis.
References
[1] Patent: CN104926747, 2018, B. Location in patent: Paragraph 0252-0254
[2] Bioorganic and Medicinal Chemistry Letters, 2009, vol. 19, # 3, p. 926 - 929
[3] Tetrahedron, 2011, vol. 67, # 24, p. 4435 - 4441
[4] Patent: EP2766359, 2016, B1. Location in patent: Paragraph 0533
