[Synthesis]
To a solution of 2-amino-1,3-propanediol (S2, 299 mg, 3.28 mmol, 1.0 eq.) in acetonitrile (MeCN, 10 mL) was added potassium carbonate (K2CO3, 2.27 g, 16.4 mmol, 5.0 eq.) and benzyl bromide (0.98 mL, 1.4 g, 8.3 mmol, 2.5 eq.). The reaction mixture was stirred at room temperature for 18 h and subsequently diluted with water (10 mL). The aqueous layer was extracted with ethyl acetate (EtOAc, 3 x 10 mL) and the combined organic phases were dried over anhydrous sodium sulfate (Na2SO4). The solvent was removed by concentration under reduced pressure and the residue was purified by silica gel column chromatography (SiO2, petroleum ether/ethyl acetate 1:1) to afford 2-(N,N-dibenzyl)amino-1,3-propanediol (S3, 716 mg, 2.64 mmol, 80% yield) as a white solid. Thin Layer Chromatography (TLC) Rf 0.20 (petroleum ether/ethyl acetate 1:1); melting point 113°C; 1H NMR (300 MHz, C6D6) δ: 2.30 (bs, 2H, OH), 2.93 (tt, 1H, J = 7.5, 5.9 Hz, 2-H), 3.37 (dd, 2H, J = 10.8, 5.9 Hz, 1-Ha, 3- Ha), 3.48 (dd, 2H, J = 10.8, 7.5 Hz, 1-Hb, 3-Hb), 3.53-3.66 (m, 4H, CH2Ph), 7.01-7.32 (m, 10H, Ph-H); 13C NMR (76 MHz, C6D6) δ: 54.4, 60.2, 60.3, 127.4, 128.7, 129.2, 140.1; infrared spectra (ATR) ν: 3245, 1493, 1451, 1049, 1025, 999, 741, 730, 695 cm-1; UV spectra (MeCN) λmax (logε): 206 (4.28), 259 (2.77) nm; mass spectra (ESI+) m/z: 272.2 (M + H+), 294.2 (M + Na+); high-resolution mass spectrometry (ESI+) m/z: C17H21NNaO2 294.1465 (M + Na+) calculated, 294.1466 measured. |
[References]
[1] Journal of Organic Chemistry, 2012, vol. 77, # 21, p. 9641 - 9651
[2] European Journal of Organic Chemistry, 2008, # 1, p. 53 - 63
[3] Bioorganic and Medicinal Chemistry, 2007, vol. 15, # 1, p. 186 - 193
[4] Beilstein Journal of Organic Chemistry, 2014, vol. 10, p. 1135 - 1142
[5] Chemistry - A European Journal, 2018, vol. 24, # 60, p. 16136 - 16148 |