Putrescine → L-Phenylalanine

Participants

Reaction Steps

N,N-dimethylphenylalanine (15) (1.19 g, 6.2 mmol), Et3N (1.29 ml, 9.3 mmol), and 1,4-diamino butane (303 μl, 3.0 mmol) were dissolved in CH3CN (50 mL). O-benzotriole-N,N,N′,N′-tetramethyl-uronium-hexafluoro-phosphate (HBTU) was added, and the reaction mixture was stirred at room temperature for 30 minutes, and then concentrated under reduced pressure. The mixture was vacuum filtered (EtOAc), further concentrated under reduced pressure, and subjected to flash chromatography (EtOAc, then 10% Et3N in EtOAc) to afford 1.06 g (80%, non-optimized) of (16a) as white crystals. [α]25−105.7 (c=0.19, CHCl3); FTIR (neat) 1649, 1455, 1384, 748, 700 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.19-7.16 (m, 8H), 6.89 (t, J=5.7 Hz, 211), 6.40 (s, 1H), 5.90 (s, 1H), 3.13-3.04 (m, 6H), 3.12 (dd, J=12.7, 5.3 Hz, 2H), 2.79 (dd, J=13.4, 5.1 Hz, 2H), 2.23 (s, 12H), 1.24 (s, 4H); 13C NMR (100 MHz, CDCl3) δ 171.68, 129.44, 128.88, 127.91, 125.69, 70.61, 41.91, 38.25, 32.84, 26.52; HRMS calculated for C26H39N4O2 (M+H)+ required 439.3073, found 439.3074.

Provenance & Evidence