N-benzylbut-3-en-1-amine

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

Procedure: To a solution of (S)-2-(tert-butoxycarbonylamino)pent-4-enoic acid (400 mg, 1.86 mmol), N-benzylbut-3-en-1-amine (449 mg, 2.79 mmol) in DMF (5 mL) was added EDC (410 mg, 2.14 mmol), HOBt (370 mg, 2.42 mmol) and followed by TEA (0.259 mL, 1.858 mmol). The reaction was stirred at rt for 3 days. The reaction was diluted with EtOAc and washed with water (2×), 1 M aqueous KHSO4 (2×), saturated aqueous NaHCO3 (2×) and saturated aqueous NaCl. The organic layer was separated, dried over Na2SO4, filtered and concentrated. The crude product was purified using silica gel chromatography (ISCO system) eluting with a gradient of 0-60% EtOAc/Hex to give (S)-tert-butyl 1-(benzyl(but-3-enyl)amino)-1-oxopent-4-en-2-ylcarbamate (270 mg, 0.753 mmol, 40.5% yield). Anal. Calcd. for C21H30N2O3 m/z 358.4. found: 359.1 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 7.43-7.13 (m, 5H), 5.85-5.62 (m, 2H), 5.40-5.27 (m, 1H), 5.19-4.97 (m, 3H), 4.87 and 4.37 (d, J=14.9 Hz, 1H), 4.76-4.51 (m, 2H), 3.59-3.22 (m, 3H), 2.39 (ddq, J=25.6, 21.3, 7.1 Hz, 4H), 1.44 and 1.42 (s, 9H). washed with water (2×), 1 M aqueous KHSO4 (2×), saturated aqueous NaHCO3 (2×) and saturated aqueous NaCl The organic layer was separated dried over Na2SO4 filtered concentrated The crude product was purified eluting with a gradient of 0-60% EtOAc/Hex

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

Procedure: To a solution of (E)-N-benzylidenebut-3-en-1-amine (1.298 gm, 8.15 mmol) in EtOH (25 mL) cooled to 0° C. was added NaBH4 (0.324 g, 8.56 mmol) portionwise over 40 min. After addition, the reaction mixture was stirred at rt for 3 hr. The reaction mixture was filtered and the filtrate was concentrated to give a white semi-solid residue. To the residue 50 mL of DCM was added. The resulting milky solution was stirred for 15 min and then was filtered. The obtained clear filtrate was concentrated to give N-benzylbut-3-en-1-amine (1.30 g, 6.85 mmol, 84% yield) as a pale yellow oil. Anal. Calcd. for C11H15N m/z 161.2. found: 162.0 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 7.42-7.21 (m, 5H), 5.79 (ddt, J=17.1, 10.2, 6.9 Hz, 1H), 5.13-4.99 (m, 2H), 3.80 (d, J=6.8 Hz, 2H), 3.29 (q, J=6.8 Hz, 1H), 2.71 (q, J=6.9 Hz, 1H), 2.29 (q, J=6.8 Hz, 1H), 1.25 (dt, J=9.1, 7.1 Hz, 1H), 1.12-1.03 (m, 1H). After addition The reaction mixture was filtered the filtrate was concentrated to give a white semi-solid residue The resulting milky solution was stirred for 15 min was filtered The obtained clear filtrate was concentrated

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

Procedure: To a solution of (E)-N-benzylidenebut-3-en-1-amine (1.298 gm, 8.15 mmol) in EtOH (25 mL) cooled to 0° C. was added NaBH4 (0.324 g, 8.56 mmol) portionwise over 40 min. After addition, the reaction mixture was stirred at rt for 3 hr. The reaction mixture was filtered and the filtrate was concentrated to give a white semi-solid residue. To the residue 50 mL of DCM was added. The resulting milky solution was stirred for 15 min and then was filtered. The obtained clear filtrate was concentrated to give N-benzylbut-3-en-1-amine (1.30 g, 6.85 mmol, 84% yield) as a pale yellow oil. Anal. Calcd. for C11H15N m/z 161.2. found: 162.0 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 7.42-7.21 (m, 5H), 5.79 (ddt, J=17.1, 10.2, 6.9 Hz, 1H), 5.13-4.99 (m, 2H), 3.80 (d, J=6.8 Hz, 2H), 3.29 (q, J=6.8 Hz, 1H), 2.71 (q, J=6.9 Hz, 1H), 2.29 (q, J=6.8 Hz, 1H), 1.25 (dt, J=9.1, 7.1 Hz, 1H), 1.12-1.03 (m, 1H). After addition The reaction mixture was filtered the filtrate was concentrated to give a white semi-solid residue The resulting milky solution was stirred for 15 min was filtered The obtained clear filtrate was concentrated

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

Procedure: The product of step A (24.5 g, 0.15 mol) was dissolved in acetonitrile/water (1:1, 500 mL) and treated with glyoxylic acid monohydrate (15.3 g, 0.17 mol). The resulting solution was allowed to stir at ambient temperature for 12 h. The reaction mixture was concentrated in vacuo, made basic via addition of 1 M NaOH (500 mL) and extracted with dichloromethane (3×200 mL). The combined organic extracts were dried over Na2SO4, filtered, and concentrated in vacuo to afford crude 1-benzyl-4-hydroxypiperidine-2-carboxylic acid (24 g, 69%) as a colorless oil which was used without further purification: 1H NMR (CDCl3, 400 MHz) δ 7.38-7.27 (m, 5H), 4.82 (t, J=5.2 Hz, 1H), 3.73-3.59 (m, 2H), 3.30 (d, J=4.8 Hz, 1H), 3.03 (dd, J=12.0, 6.4 Hz, 1H), 2.50-2.43 (m, 1H), 2.29-2.19 (m 1H), 2.08-1.98 (m, 1H), 1.97-1.88 (m, 2H). The reaction mixture was concentrated in vacuo made basic via addition of 1 M NaOH (500 mL) extracted with dichloromethane (3×200 mL) The combined organic extracts were dried over Na2SO4 filtered concentrated in vacuo

Conditions: temp:75.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of benzylamine (100 mL, 0.9 mol) and 4-bromobut-1-ene (25 g, 0.18 mmol) in ethanol (250 mL) was added sodium iodide (1.0 g, 6.7 mmol). The reaction mixture was degassed via argon bubbling for 20 min then heated to 75° C. for 4 h. After cooling, the reaction mixture was diluted with dichloromethane (1 L) and 1M KOH (500 mL) was added. The two phases were separated and the aqueous layer was further extracted with dichloromethane (3×200 mL). The combined organic layers were dried over Na2SO4, filtered, and concentrated in vacuo. Purification by flash chromatography (SiO2, ethyl acetate to 10:1 ethyl acetate/triethylamine) provided N-benzylbut-3-en-1-amine (24.5 g, 84%) as a colorless oil: 1H NMR (CDCl3, 400 MHz) δ 7.31-7.28 (m, 3H), 7.24-7.21 (m, 2H), 5.82-5.72 (m, 1H), 5.10-5.00 (m, 2H), 3.77 (s, 2H), 2.68 (t, J=6.8 Hz, 2H), 2.29-2.23 (m, 2H), 1.36 (br s, 1H). The reaction mixture was degassed via argon bubbling for 20 min After cooling the reaction mixture was diluted with dichloromethane (1 L) and 1M KOH (500 mL) was added The two phases were separated the aqueous layer was further extracted with dichloromethane (3×200 mL) The combined organic layers were dried over Na2SO4 filtered concentrated in vacuo Purification by flash chromatography (SiO2, ethyl acetate to 10:1 ethyl acetate/triethylamine)

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

Procedure: To a solution of (S)-2-(tert-butoxycarbonylamino)pent-4-enoic acid (400 mg, 1.86 mmol), N-benzylbut-3-en-1-amine (449 mg, 2.79 mmol) in DMF (5 mL) was added EDC (410 mg, 2.14 mmol), HOBt (370 mg, 2.42 mmol) and followed by TEA (0.259 mL, 1.858 mmol). The reaction was stirred at rt for 3 days. The reaction was diluted with EtOAc and washed with water (2×), 1 M aqueous KHSO4 (2×), saturated aqueous NaHCO3 (2×) and saturated aqueous NaCl. The organic layer was separated, dried over Na2SO4, filtered and concentrated. The crude product was purified using silica gel chromatography (ISCO system) eluting with a gradient of 0-60% EtOAc/Hex to give (S)-tert-butyl 1-(benzyl(but-3-enyl)amino)-1-oxopent-4-en-2-ylcarbamate (270 mg, 0.753 mmol, 40.5% yield). Anal. Calcd. for C21H30N2O3 m/z 358.4. found: 359.1 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 7.43-7.13 (m, 5H), 5.85-5.62 (m, 2H), 5.40-5.27 (m, 1H), 5.19-4.97 (m, 3H), 4.87 and 4.37 (d, J=14.9 Hz, 1H), 4.76-4.51 (m, 2H), 3.59-3.22 (m, 3H), 2.39 (ddq, J=25.6, 21.3, 7.1 Hz, 4H), 1.44 and 1.42 (s, 9H). washed with water (2×), 1 M aqueous KHSO4 (2×), saturated aqueous NaHCO3 (2×) and saturated aqueous NaCl The organic layer was separated dried over Na2SO4 filtered concentrated The crude product was purified eluting with a gradient of 0-60% EtOAc/Hex

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

Procedure: To a solution of (E)-N-benzylidenebut-3-en-1-amine (1.298 gm, 8.15 mmol) in EtOH (25 mL) cooled to 0° C. was added NaBH4 (0.324 g, 8.56 mmol) portionwise over 40 min. After addition, the reaction mixture was stirred at rt for 3 hr. The reaction mixture was filtered and the filtrate was concentrated to give a white semi-solid residue. To the residue 50 mL of DCM was added. The resulting milky solution was stirred for 15 min and then was filtered. The obtained clear filtrate was concentrated to give N-benzylbut-3-en-1-amine (1.30 g, 6.85 mmol, 84% yield) as a pale yellow oil. Anal. Calcd. for C11H15N m/z 161.2. found: 162.0 (M+H)+; 1H NMR (400 MHz, CDCl3) δ ppm 7.42-7.21 (m, 5H), 5.79 (ddt, J=17.1, 10.2, 6.9 Hz, 1H), 5.13-4.99 (m, 2H), 3.80 (d, J=6.8 Hz, 2H), 3.29 (q, J=6.8 Hz, 1H), 2.71 (q, J=6.9 Hz, 1H), 2.29 (q, J=6.8 Hz, 1H), 1.25 (dt, J=9.1, 7.1 Hz, 1H), 1.12-1.03 (m, 1H). After addition The reaction mixture was filtered the filtrate was concentrated to give a white semi-solid residue The resulting milky solution was stirred for 15 min was filtered The obtained clear filtrate was concentrated