Reaction SMILES: [CH3:1][O:2][C:3](=[O:38])[CH2:4][N:5]1[C:11](=[O:12])[C@@H:10]([NH:13]C(=O)CCC2C=CC=CC=2)[CH2:9][N:8](C(=O)CCC2C=CC=CC=2)[C:7]2[CH:34]=[CH:35][CH:36]=[CH:37][C:6]1=2.[ClH:39].COC(=O)CN1C(=O)[C@@H](NC(OC(C)(C)C)=O)CNC2C=CC=CC1=2>C(OCC)(=O)C>[ClH:39].[CH3:1][O:2][C:3](=[O:38])[CH2:4][N:5]1[C:11](=[O:12])[C@@H:10]([NH2:13])[CH2:9][NH:8][C:7]2[CH:34]=[CH:35][CH:36]=[CH:37][C:6]1=2
Reactant: COC(=O)CN1C(=O)[C@@H](NC(=O)CCc2ccccc2)CN(C(=O)CCc2ccccc2)c2ccccc21
Agent: COC(=O)CN1C(=O)[C@@H](NC(=O)OC(C)(C)C)CNc2ccccc21
Agent: Cl
Solvent: CCOC(C)=O
Product: COC(=O)CN1C(=O)[C@@H](N)CNc2ccccc21
Temperature: 25 °C
Reaction time: 1 h

Procedure:
Anhydrous hydrogen chloride was bubbled into a solution of (3(S)-tert-butoxycarbonylamino-2-oxo-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl)acetic acid methyl ester (103, 1 g, 2.86 mmol) in 25 ml of ethyl acetate for 2 minutes then stirred for 1 hour at room temperature. The reaction was evaporated to give 2-oxo-3(S)-amino-2,3,4,5-tetrahydrobenzo[b][1,4]diazepin-1-yl acetic acid methyl ester hydrochloride as a white solid. The hydrochloride salt and hydrocinnamic acid (0.47 g, 3.15 mmol) was dissolved into 20 ml of dimethylformamide and cooled to 0° C. Diisopropylethylamine (1 ml, 5.72 mmol) was added to the solution followed by the addition of N-hydroxybenzotriazole and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride. After stirring for 18 hours at room temperature, the mixture was diluted with 150 ml of ethyl acetate and washed with 10% sodium hydrogen sulfate, 10% sodium bicarbonate, and brine. The organic layer was dried over anhydrous sodium sulfate, filtered, and evaporated to a crude solid that was purified by flash chromatography eluting with 7:3 ethyl acetate/dichloromethane to afford 600 mg (55%)of the title compound as a white solid. 1H NMR (CDCl3) δ 7.3-6.85 (9H, m), 6.55-6.0 (1H, d), 4.88-4.82 (1H, m), 4.72-4.65 (1H, d), 4.28-4.22 (1H, m), 3.95-3.9 (1H, m), 3.78 (3H, s), 3.65 (1H, br. s), 3.28-3.2 (1H, m), 2.95-2.84 (2H, m), 2.55-2.4 (2H, m). (3(S)-(3-Phenylpropionylamino)-2-oxo-2,3,4,5-tetra-hydrobenzo[b][1,4]diazepin-1-yl)acetic acid (105a). (3(S)-(3-Phenylpropionylamino)-2-oxo-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl)acetic acid methyl ester (104a) was dissolved in 90% methanol. Lithium hydroxide hydrate was added to the reaction and the reaction was stirred at room temperature for 4 h. The reaction was evaporated in vacuo to give a white solid. This was dissolved in 20 ml of water and acidified to pH 5 and extracted with ethyl acetate to afford 304 mg (88%) of the title compound as a white solid. 1H NMR (CDCl3) δ 7.5-6.9 (11H, m), 4.92-4.8 (1H, m), 4.7-4.58 (1H, d), 4.38-4.25 (1H, d), 3.88-3.78 (1H, m), 3.45-3.25 (1H, m), 3.05-2.85 (2H, m), 2.55-2.45 (2H, m). 4-Oxo-3(S)-{2-[2-oxo-3(S)-(3-phenylpropionylamino)-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-ylacetylamino}butyric acid (106a). N-[1-(2-Benzyloxy-5-oxotetrahydrofuran-3-ylcarbamoyl-methyl)-2-oxo-2,3,4,5-tetrahydro-1H-benzo[b][1,4]diazepin-3-yl]-3-phenylpropionamide was prepared from 105a by the procedure in example 3, compound H (step A) to afford 390 mg (93%) of the product as diastereomers. 1H NMR (CD3OD) 67.58-7.22 (14H, m), 5.78-5.73 (0.5 H, d), 5.64 (0.5 H, s), 5.0-4.72 (4H, m), 4.54-4.42 (2H, m), 3.82-3.76 (0.5 H, m), 3.68-3.62 (0.5 H, m), 3.28-3.21 (0.5H, m), 3.19-3.12 (0.5H, m), 3.07-2.98 (2H, m), 2.78-2.48 (4H, m). The resulting product was converted to 106a by the method described in example 3, compound H (Step D) to afford the title compound as a white solid (17%): 1H NMR (CD3OD) δ 7.54-6.98 (9H, m), 5.58-5.44 (1H, m), 4.8-4.2 (4H, m), 3.96-3.3 (2H, m), 3.30-3.05 (1H, m), 2.98-2.25 (5H, m). [2-Oxo-5-(3-phenylpropionyl)-3(S)-(3-phenylpropionylamino)-2,3,4,5-tetrahydrobenzo[b][1,4]diazepin-1-yl]acetic acid methyl ester (104b). Anhydrous hydrogen chloride was bubbled into a solution of (3(S)-tert-butoxycarbonylamino-2-oxo-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl)acetic acid methyl ester (103, 1 g, 2.86 mmol) in 25 ml of ethyl acetate for 2 minutes then stirred for 1 hour at room temperature. The reaction was evaporated to give 2-oxo-3(S)-amino-2,3,4,5-tetrahydrobenzo[b][1,4]diazepin-1-yl acetic acid methyl ester hydrochloride as a white solid. The hydrochloride salt was suspended into 20 ml of dichloromethane and cooled to 0° C. Triethylamine (1.6 ml, 11.5 mmol) was added to the suspension followed by the dropwise addition of dihydrocinnamoyl chloride (0.9 ml, 6 mmol). The mixture was warmed to room temperature and stirred for 18 hours. The mixture was diluted with 25 ml of dichloromethane and washed twice with 50 ml of water and once with 50 ml of brine. The organic layer was dried over anhydrous sodium sulfate, filtered, and evaporated to give a viscous, yellow oil that was purified by flash chromatography eluting with 1:1 ethyl acetate/dichloromethane to afford 1.35 g (92%) of the title product as a white solid. 1H NMR (CDCl3) δ 7.45-7.02 (14 H, m), 6.37-6.32 (1H, d), 4.78-4.72 (1H, m), 4.52-4.3 (3H, m), 3.82-3.77 (1H, m), 3.74 (3H, s), 3.03-2.87 (4H, m), 2.58-2.45 (2H, m), 2.45-2.35 (1H, m), 2.25-2.16 (1H, m). [2-Oxo-5-(3-phenylpropionyl)-3-(3(S)-phenylpropionylamino)-2,3,4,5-tetrahydrobenzo[b][1,4]diazepin-1-yl]acetic acid (105b). [2-Oxo-S-(3-phenylpropionyl)-3-(3-phenylpropionylamino)-2,3,4,5-tetrahydrobenzo[b][1,4]diazepin-1-yl]acetic acid methyl ester (104b; 680 mg, 1.32 mmol) was hydrolyzed by the procedure in example 105a to afford 645 mg (98%) of the title compound as a white solid. 1H NMR (CDCl3) δ 7.58 (1H, br. s), 7.5-7.42 (1H, m), 7.35-6.95 (14H, m), 4.95-4.88 (1H, m), 4.64-4.55 (1H, d), 4.54-4.45 (1H, t), 4.15-4.05 (1H, d), 3.75 (1H, m), 3.05-2.75 (4H, m), 2.58-2.45 (2H, m), 2.45-2.28 (1H, m), 2.25-2.14 (1H, m). 2-Oxo-3(S)-{2-[2-oxo-5-(3-phenylpropionyl)-3(S)-(3-phenyl-propionyl-amino)-2,3,4,5-tetrahydrobenzo[b][1,4]diazepin-1-yl]acetylamino}butyric acid (106b). [2-Oxo-5-(3-phenylpropionyl)-3-(3-phenylpropionylamino)-2,3,4,5-tetrahydrobenzo[b][1,4]diazepin-1-yl]acetic acid and 3-amino-4-oxobutyric acid tert-butylester semicarbazone were coupled by the procedure in example 3, compound K (step A) to give 350 mg (85%) of a white solid. 1H NMR (CDCl3) δ 9.05 (1H, br. s), 7.58-7.55 (1H, d), 7.5-7.35 (1H, m), 7.35-6.95 (14 H, m), 6.75-6.72 (1H, d), 6.25 (1H, br. s), 5.25 (1H, br. s), 4.95-4.88 (1H, m), 4.8-4.72 (1H, m), 4.55-4.4 (2H, m), 3.92-3.88 (1H, d), 3.73-3.68 (1H, m), 2.95-2.8 (4H, m), 2.8-2.72 (1H, m), 2.62-2.55 (1H, m), 2.55-2.45 (2H, m), 2.4-2.32 (1H, m), 2.2-2.12 (1H, m), 1.45 (9H, s). 4-Oxo-3-{2-[2-oxo-5-(3-phenylpropionyl)-3-(3-phenyl-propionyl-amino)-2,3,4,5-tetrahydrobenzo[b][1,4]diazepin-1-yl]-acetyl-amino}butyric acid tert-butyl ester semicarbazone was deprotected as described in example 3, compound K (step C) to give 118 mg (47%) of the title compound as a white solid. 1H NMR (CD3OD) 67.48-6.95 (14 H, m), 4.65-4.15 (6H, m), 3.5-3.4 (1H, m), 2.85-2.72 (4H, m), 2.65-2.5 (1H, m), 2.5-2.34 (3H, m), 2.34-2.15 (2H, m). [5-Benzyl-2-oxo-3(S)-(3-phenylpropionylamino)-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl]acetic acid methyl ester (104c). [2-Oxo-3-(3-phenylpropionylamino)-2,3,4,5-tetrahydrobenzo-[b][1,4]diazepin-1-yl]acetic acid methyl ester (104a; 500 mg, 1.31 mmol), calcium carbonate (155 mg, 1.58 mmol), and benzyl bromide (170 μl, 1.44 mmol) were taken into 10 ml of dimethylformamide and heated to 80° C. for 8 hours. The mixture was diluted with 150 ml of ethyl acetate and washed 4 times with 50 ml of water. The organic layer was dried over anhydrous sodium sulfate, filtered, and evaporated to give a viscous, yellow oil that was purified by flash chromatography eluting with dichloromethane/ethyl acetate (8:2) to give 460 mg (75%) of the title compound as a white solid. 1H NMR (CDCl3) δ 7.34-7.05 (14 H, m), 6.32-6.28 (1H, d), 4.84-4.76 (1H, d), 4.76-4.70 (1H, m), 4.43-4.37 (1H, d), 4.26-4.18 (1H, d), 4.06-4.00 (1H, d), 3.79 (3H, s), 3.45-3.37 (1H, m), 3.02-2.95 (1H, m), 2.90-2.82 (2H, m), 2.5-2.34 (2H, m). [5-Benzyl-2-oxo-3(S)-(3-phenylpropionylamino)-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl]acetic acid (105c) was prepared by the hydrolysis of the ester (102c) by the procedure reported in example 105a to give 450 mg (98%) of the title compound as a white solid: 1H NMR (CD3OD) 67.5-7.05 (14 H, m), 6.4 (1H, br. s), 4.85-4.55 (2H, m), 4.5-4.21 (2H, m), 4.12-3.92 (1H, d), 3.45-3.3 (1H, m), 3.1-2.8 (3H, m), 2.55-2.28 3H, m). 3(S)-{2-[5-Benzyl-2-oxo-3-(3(S)-phenylpropionylamino)-2,3,4,5-tetrahydrobenzo[b][1, 4]diazepin-1-yl]-acetylamino}-4-oxobutyric acid (106c). [5-Benzyl-2-oxo-3(S)-(3-phenylpropionylamino)-2,3,4,5-tetrahydro-benzo[b][1,4]diazepin-1-yl]acetic acid and 3(S)-amino-4-oxobutyric acid tert-butylester semicarbazone were coupled by the procedure in example 3, compound K (step A) and to afford 260 mg (85%) of a white solid: