C([O:3][C:4](=[O:21])[CH2:5][NH:6][C:7]([C:9]1[CH:14]=[CH:13][C:12]([C:15]2[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=2)=[CH:11][N:10]=1)=[O:8])C.CO.O.O[Li].O>C1COCC1>[C:15]1([C:12]2[CH:13]=[CH:14][C:9]([C:7]([NH:6][CH2:5][C:4]([OH:21])=[O:3])=[O:8])=[N:10][CH:11]=2)[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=1To a stirred solution of 5-phenyl-pyridine-2-carboxylic acid (0.3 g, 0.00151 mol) in DMF (5 mL) was added DIPEA (0.580 g, 0.00452 mol), HOBt (0.243 g, 0.00180 7 mol) and EDCI.HCl (0.346 g, 0.001807 mol) at ambient temperature. After 2 minutes glycine ethyl ester hydrochloride (0.252 g, 0.00181 mol) was added and the resulting mixture was stirred overnight. The reaction mixture was then diluted with cold water and the product was extracted with ethyl acetate. The ethyl acetate layer was washed with brine solution, dried over sodium sulfate and concentrated under reduced pressure to afford 0.32 g (75%) of [(5-phenyl-pyridine-2-carbonyl)-amino]-acetic acid ethyl ester. To a stirred solution of [(5-phenyl-pyridine-2-carbonyl)-amino]-acetic acid ethyl ester (0.32 g, 0.00113 mol) in a mixture of THF (3.2 mL), methanol (2 mL) and H2O (1 mL) was added LiOH.H2O (0.142 g, 0.00338 mol) and the resulting mixture was stirred at ambient temperature overnight. Volatiles were removed by evaporation and the resulting residue was diluted with water and acidified with 10% HCl. The product was extracted with ethyl acetate, which was dried over sodium sulfate and concentrated under reduced pressure to afford 0.24 g (83%) of [(5-phenyl-pyridine-2-carbonyl)-amino]-acetic acid.
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