[CH3:1][O:2][C:3](=[O:24])[C:4]1[CH:9]=[C:8]([O:10][CH2:11][CH3:12])[CH:7]=[C:6]([NH:13]C(OCC2C=CC=CC=2)=O)[CH:5]=1.O>[Pd].CO>[CH3:1][O:2][C:3](=[O:24])[C:4]1[CH:9]=[C:8]([O:10][CH2:11][CH3:12])[CH:7]=[C:6]([NH2:13])[CH:5]=1A mixture of 3-benzyloxycarbonylamino-5-ethoxy-benzoic acid methyl ester (D47) (15 g, 45.5 mmol, 1 equiv), 10% palladium on charcoal (50% wet, 1.5 g, 5% w/w) and NH4COOH (15 g, 455 mmol, 10 equiv) H2O (50 ml) and MeOH (200 ml) was stirred at 50° C. for 2 h. The mixture was cooled to room temperature and the catalyst was filtered off through a pad of celite. Most of the MeOH was removed in vacuo and the residue was partitioned between saturated aqueous NaHCO3 solution and AcOEt. The aqueous phase was re-extracted with AcOEt. The combined organic phases were dried over MgSO4 and concentrated in vacuo to give 3-amino-5-ethoxy-benzoic acid methyl ester (D49) (8.8 g, 99%) as a pale green solid which was used in the next step without further purification. [M+H]+=196.1, RT=2.49 min
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