Reaction Steps
(RS)-5-(4-Hydroxy-phenyl)-4-(7-phenyl-heptanoylamino)-pentanoic acid methyl ester 92 (889 mg, 2.16 mmol), 2-picolylchloride hydrochloride (570 mg, 3.47 mmol) and finely powdered anhydrous K2CO3 (1.45 g, 10.5 mmol) was stirred in dry DMF (7 mL) for 48 hr. The mixture was poured onto water (40 mL) and extracted into EtOAc. The extract was successively washed with HCl solution (1 M, 30 mL), saturated NaHCO3 solution, brine, and then dried with MgSO4. Concentration of the solvent in vacuo afforded 93 (747 mg, 69 %): 1H NMR (CDCl3) δ 1.15-1.40 (m, 4H); 1.40-1.70 (m, 5H); 1.73-1.85 (m, 1H); 2.08 (t, J=7.6 Hz, 2H); 2.34 (m, 2H); 2.58 (t, J=7.6 Hz, 2H); 2.69 (dd, J=15, 6.9 Hz, 1H); 2.77 (dd, J=15, 6.2 Hz, 1H); 3.64 (s, 3H); 4.06-4.21 (m, 1H); 5.17 (s, 2H); 5.37 (d, J=9.3 Hz, 1H); 6.91 (d, J=8.4 Hz, 2H); 7.10 (d, J=8.4 Hz, 2H); 7.12-7.31 (m, 6H); 7.51 (d, J=7.5 Hz, 1H); 7.71 (dt, J=7.5, 1.6 Hz, 1H); 8.60 (m, J=6.0 Hz, 1H). 13C NMR (CDCl3) δ 174.4, 173.0, 157.5, 157.3, 149.4, 142.8, 137.0, 130.3, 125.8, 122.8, 121.5, 130.6, 128.5, 128.4, 115.0, 70.8, 51.9, 50.2, 40.6, 37.0, 36.0, 31.4, 31.1, 29.2, 29.1, 29.0, 25.8. ESMS 503 (M+H)+.
