[C:1]1([C:7]2([C:13]#[N:14])[CH2:12][CH2:11][NH:10][CH2:9][CH2:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C=O.[C:17](O[BH-](OC(=O)C)OC(=O)C)(=O)C.C(O)(=O)C>CN(C)C=O.COC(OC)OC.Cl>[CH3:17][N:10]1[CH2:9][CH2:8][C:7]([C:1]2[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=2)([C:13]#[N:14])[CH2:12][CH2:11]1
4-Phenylpiperidine-4-carbonitrile (1.35 g, 6.062 mmol) was dissolved in N,N-dimethylformamide/trimethylorthoformate (1:1, 12 mL) and treated with paraformaldehyde (0.596 mL, 18.19 mmol), triacetoxyborohydride (3.854 g, 18.185 mmol) and acetic acid (1 mL). The mixture was stirred at 23° C. overnight, then diluted with 1N hydrochloric acid and washed with ethyl acetate. The aqueous phase was basified with aqueous sodium bicarbonate and extracted with ethyl acetate. The combined organic extracts were dried over anhydrous magnesium sulfate, filtered and concentrated to give the title material (1.05 g, 50%) as an oil. LC/MS (M+H)+: 200. HPLC ret. time (Condition B): 1.315 min. 1H NMR (400 MHz, CDCl3) δ ppm: 2.10-2.21 (4H, m), 2.41 (3H, s), 2.53 (2H, td, J=11.81, 3.41 Hz), 2.99 (2H, d, J=12.38 Hz), 7.32-7.38 (1H, m), 7.39-7.45 (2H, m), 7.49-7.54 (2H, m).
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