Reaction Steps
Intermediate 57 was prepared as described above for the preparation of intermediate 52. From 575 mg of N-(Boc)-L-Tyrosine methyl ester and 500 mg of Intermediate 9B was prepared 940 mg of BOC-protected intermediate methyl ester (94% yield; 1H NMR (DMSO-d6, 300 MHz) δ7.93 (m, 2H), 7.47-7.41 (m, 3H), 7.04 (d, 2H, J=8.4), 6.86 (d, 2H, J=8.6), 4.96 (d, 1H, J=4.56 (m, 1H), 4.34 (t, 2H, J=6.8), 3.73 (s, 3H), 3.23 (t, 2H, J=6.9), 3.04 (m, 2H), 2.90 (q, 2H, J=7.5), 1.44 (s, 9H), 1.37 (t, 3H, J=7.5)); From 900 mg of protected intermediate was prepared 900 mg of intermediate 57 as a solid. 1H NMR (DMSO-d6, 300 MHz) δ8.16 (br s, 2H), 7.85 (m, 2H), 7.5-7.43 (m, 3H), 7.14 (d, 2H, J=8.6), 6.90 (d, 2H, J=8.6), 4.27 (t, 2H, J=6.5), 4.12 (m, 1H), 3.12 (t, 2H, J=6.5), 3.0 (m, 2H), 2.86 (q, 2H, J=7.5), 1.26 (t, 3H, J=7.5).
