4-nitro-2-phenylbenzoic acid (0.30 g, 1.23 mmol), methionine methyl ester hydrochloride salt (0.27 g, 1.35 mmol), EDCI (0.26 g, 1.35 mmol), HOBT (0.18 g, 1.35 mmol) and Et3N (0.19 ml) in dry CH2Cl2 (4.9 ml) were reacted according to the above procedure and worked up as described for N-BOC-4-aminobenzoyl methionine methyl ester in Example 1. After recrystallization from ethyl acetate and hexanes, 0.41 g (85.5%) of pure product was isolated. mp 98°-101° C.; 1H NMR (CDCl3) 1.62-1.73 (1 H, m), 1.79-1.88 (1 H, m), 1.91 (3 H, s), 1.99 (2 H, t, J=7.2 Hz), 3.59 (3 H, s), 4.53 (1 H, m), 6.45 (1 H, d, J=7.8 Hz), 7.33-7.40 (5 H, m), 7.67 (1 H, d, J=8.3 Hz), 8.07-8.12 (2 H, m); 13C NMR (CDCl3) 14.92, 29.11, 30.67, 51.51, 52.29, 121.86, 124.74, 128.27, 128.60, 128.69, 129.52, 137.50, 140.56, 141.02, 148.09, 167.23, 171.23; m/ z (FAB) , 389 (M+1).
