Reaction Steps
compound NR36. Same procedure as above with HCl, Trp-OCH3 (255 mg, 1 mmol), N-Boc-Tyr(Bn)-Ala-OH (444 mg, 1 mmol), DCC (259 mg, 1.26 mmol) and HOBt (172 mg, 1.27 mmol) in THF (15 mL). The crude residue was chromatographed over silica gel to afford a white solid (361 mg, 56%). 1H NMR (300 MHz, DMSO-d6) δ 1.22 (d, J=7 Hz, 3H, CH3), 1.29 (s, 9H, (CH3)3), 2.62 and 2.92 (ABX system, 2H, CH2P), 3.08 and 3.13 (ABX system, 2H, CH2β) 3.55 (s, 3H, OCH3), 4.10 (m, 1H, CHα), 4.36 (m, 1H, CHα), 4.49 (m, 1H, CHα), 5.03 (s, 2H, CH2 (OBn)), 6.85-7.50 (m, 15H, 14 aromatic H+1 NH), 7.97 (d, J=7.3 Hz, 1H), 8.34 (d, J=7.0 Hz, 1H), 10.88 (s, 1NH). 13C NMR (75 MHz, DMSO-d6) δ 18.2 (CH3), 26.8 (CH2 Trp), 28.0 ((CH3)3), 36.3 (CH2 Tyr), 47.6, 51.6, 53.0, 55.6 (CHα Ala, Tyr, Trp or OCH3), 69 (CH2 (OBn)), 77.9 (C(CH3)3), 109.0 (aromatic C), 111.2, 114.2, 117.8, 118.3, 120.8, 123.6 (aromatic CH), 126.9 (aromatic C), 127.4, 127.6, 128.2, 130.0 (aromatic CH), 130.2, 135.9, 137.1 (aromatic C), 155.1, 156.7 (Car-O or CO carbamate), 171.2, 171.9, 172.1 (2 CO amide or CO ester). Anal. Calcd. for C36H42N4O7, 0.5H2O: C, 66.34; H, 6.65; N, 8.60. Found: C, 66.29; H, 6.64; N, 8.48.
