Reaction SMILES: [O:1]=[C:2]1[C:7]([NH:8][C:9](=[O:18])[CH2:10][CH2:11][C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[CH:6][CH:5]=[C:4]([CH2:19][CH2:20][C:21]2C=CC=C[CH:22]=2)[N:3]1[CH2:27][C:28]([OH:30])=[O:29].[K+].[Br-]>>[CH2:19]([C:4]1[N:3]([CH2:27][C:28]([OH:30])=[O:29])[C:2](=[O:1])[C:7]([NH:8][C:9](=[O:18])[CH2:10][CH2:11][C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=2)=[CH:6][CH:5]=1)[CH2:20][CH2:21][CH3:22]
Reactant: O=C(O)Cn1c(CCc2ccccc2)ccc(NC(=O)CCc2ccccc2)c1=O
Agent: [Br-]
Agent: [K+]
Product: CCCCc1ccc(NC(=O)CCc2ccccc2)c(=O)n1CC(=O)O

Procedure:
2(S) 2-[1,2-Dihydro-2-oxo-3-(3-phenylpropionyl)amino)-1-pyridyl]propionic acid (52a). 1M Sodium hydroxide (15 ml, 15 mmol) was added to a stirred solution of 2(S) methyl 2-[1,2-dihydro-2-oxo-3(3-phenylpropionyl)amino-1-pyridyl]propionate (51a) (2.39 g, 7.3 mmol) in methanol (30 ml) at 0° C. The mixture was kept at this temperature for 2 h, acidified with 1M hydrochloric acid (15.1 ml) and extracted with ethyl acetate. The extracts were washed with brine, dried (MgSO4) and concentrated to afford 1.98 g (87%) of a colorless solid: [α]D20 −75° (1, CH2Cl2); IR (KBr) 3301, 1724, 1693, 1637, 1563, 1523, 1453, 1233, 1216, 765; 1H NMR (CDCl3) δ 8.47 (2H, m), 7.20 (5H, m), 7.03 (1H, d), 6.36 (1H, t), 5.35 (1H, q), 3.01 (2H, m), 2.70 (2H, m), 1.69 (3H, m). The following compounds were prepared in a similar manner: [6-Benzyl-1,2-dihydro-2-oxo-3-(3-phenylpropionyl)amino-1-pyridyl]acetic acid (52b), was isolated (100%) as a pale amber oil: IR (film) 3291, 1738, 1686, 1644, 1591, 1554, 1519, 1496, 1454, 1403, 1215, 1182; 1H NMR (CDCl3) δ 8.44 (1H, d, J=7.8), 8.4 (1H, s), 7.21 (10H, m), 6.19 (1H, d, J=7.8), 4.71 (2H, s), 3.90 (2H, s), 2.99 (2H, m), 2.71 (2H, m). [1,2-Dihydro-2-oxo-6-phenethyl-3-(3-phenylpropionyl) amino-1-pyridyl]acetic acid (52c), was isolated (94%) as a beige solid: mp. 214-6° C.; IR (KBr) 3289, 1740, 1680, 1640; 1H NMR (d6-DMSO) δ 9.24 (1H, s), 8.14 (1H, d, J=7.7), 7.22 (10H, m), 6.11 (1H, d, J=7.8), 4.78 (2H, s), 2.81 (8H, m) [6-Butyl-1,2-dihydro-2-oxo-3-(3-phenylpropionyl)amino-1-pyridyl]acetic acid (52d), was isolated (99%) as a pale brown solid: mp. 132-4° C.; IR (KBr) 3286, 1739, 1676, 1641, 1584, 1555, 1535, 1455, 1414, 1249, 1227, 1204; 1H NMR (CDCl3) δ 8.42 (1H, d, J=7.8), 8.37 (1H, s), 7.24 (5H, m), 6.19 (1H, d, J=7.8), 4.82 (2H, s), 3.55 (1H, s), 3.00 (2H, t), 2.67 (2H, t), 2.53 (2H, t), 1.41 (4H, m), 0.94 (3H, t). [1,2-Dihydro-6-methyl-2-oxo-3-(3-phenylpropionyl)amino-1-pyridyl]acetic acid (52e), was isolated as a solid (100%): mp. 159-61° C.; IR (KBr) 3335, 1731, 1686, 1642, 1536, 1516, 1430, 1420, 1401, 1222, 1195; 1H NMR (d6-DMSO) δ 9.21 (1H, s), 8.13 (1H, d, J=7.6), 7.20 (5H, m), 6.15 (1H, d, J=7.6), 4.77 (2H, s), 2.87 (2H, m), 2.70 (2H, m), 2.25 (3H, s). [1,2-Dihydro-2-oxo-6-phenyl-3-(3-phenylpropionyl)amino-1-pyridyl]acetic acid (52f), was isolated (100%) as a pale yellow foam: IR (KBr) 3271, 1747, 1683, 1634, 1580, 1536, 1490, 1406, 1392, 1365, 1235, 1219; 1H NMR (CDCl3) δ 8.52 (1H, d, J=7.7), 7.31 (10H, m), 6.48 (2H, s), 6.30 (1H, d, J 7.7), 4.60 (2H, s), 3.03 (2H, m), 2.71 (2H, m). [1,2-Dihydro-2-oxo-3-(3-phenylpropionyl)amino-1-pyridyl]acetic acid (52g), was isolated (94%) as a colorless solid: mp. 195-7° C.; IR (KBr) 3324, 1724, 1693, 1644, 1569, 1555, 1512, 1427, 1370, 1240; 1H NMR (d6-DMSO) δ 9.31 (1H, s), 8.23 (1H, d, J=6.8), 7.36 (1H, dd, J=6.8, 1.71), 7.25 (5H, m), 6.25 (1H, t), 4.66 (2H, s), 2.84 (4H, m). 2(R,S) 2-[6-Benzyl-1,2-dihydro-2-oxo-3-(3-phenylpropionyl)amino-1-pyridyl]-propionic acid (52h), was prepared by hydrolysis of compound 51h in aqueous tetrahydrofuran during 5 h at 40° C. to afford (95%) as a yellow oil: IR (film) 3330, 1734, 1686, 1643, 1600, 1587, 1553, 1524, 1498, 1208; 1H NMR (d6-DMSO) δ 9.29 (1H, s), 8.18 (1H, d, J=7.6), 7.21 (10H, m), 6.22 (1H, d, J=7.6), 4.82 (1H, q, J=6.6), 4.08 (2H, m), 2.76 (4H, m), 1.05 (3H, d, J=6.6). [3-(Acetyl-Tyr(Bn))amino-6-benzyl-1,2-dihydro-2-oxo-1-pyridyl]acetic acid (52%), was isolated (93%) as a foam: IR (KBr) 3302, 1731, 1646, 1603, 1562, 1512, 1454, 1428, 1379, 1231, 1178; 1H NMR (CDCl3) δ 9.48 (1H, s), 8.36 (1H, d, J=7.6), 7.30 (8H, m), 7.10 (2H, m), 6.85 (2H, d, J=8.3), 6.91 (2H, d, J=8.3), 6.71 (1H, d, J 7.6), 4.95 (1H, m), 4.90 (2H, s), 4.68 (2H, s), 3.92 (2H, s), 3.17-2.83 (2H, m), 1.92 (3H, s). [6-Benzyl-1,2-dihydro-2-oxo-3-(2-phenylethanesulphonyl)amino-1-pyridyl]acetic acid (52j), was isolated (100%) as a colorless solid: mp. 165-7° C.; IR (KBr) 3174, 1760, 1646, 1593, 1567, 1497, 1453, 1424, 1326, 1225, 1140, 1127; 1H NMR (d6-DMSO) δ 13.09 (1H, s), 9.08 (1H, s), 7.30 (11H, m), 6.02 (1H, d), 4.68 (2H, s), 4.99 (2H, s), 3.29 (2H, m), 3.03 (2H, m). [6-Benzyl-1,2-dihydro-2-oxo-3-(2-phenylethoxy) carbonylamino-1-pyridyl]acetic acid (52%), was prepared (70%) by hydrolysis of compound 49i during 1 h at 60° C.: