To a solution of acetoxyacetic acid (13.9 mg, 0.12 mmol) in methylene chloride (1 ml) were added 3-hydroxy-4-oxo-3,4-dihydro-1,2,3-benzotriazine (18.9 mg, 0.12 mmol) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (22.5 mg, 0.12 mmol), and the mixture was stirred for 3 hours. This solution was added dropwise to a solution of 3,4-difluoro-2-(2-fluoro-4-iodo-phenylamino)-N-(2-hydroxy-ethoxy)-5-(methoxyamino-methyl)-benzamide (50.0 mg, 0.10 mmol) obtained in Example 15 in THF (2 ml), and triethylamine (40.9 μl, 0.29 mmol) was added thereto. The mixture was stirred for 24 hours. The reaction mixture was diluted with ethyl acetate (45 ml), and washed with saturated aqueous ammonium chloride (20 ml), and then with saturated brine (2×20 ml). The organic layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resultant residue was roughly purified by preparative TLC (CH2Cl2/MeOH (10:1)) to give {[2,3-difluoro-4-(2-fluoro-4-iodo-phenylamino)-5-(2-hydroxy-ethoxycarbamoyl)-benzyl]-methoxy-carbamoyl}acetic acid methyl ester (14.0 mg, containing impurities) as a colorless oil. To a solution of the resultant {[2,3-difluoro-4-(2-fluoro-4-iodo-phenylamino)-5-(2-hydroxy-ethoxycarbamoyl)-benzyl]-methoxy-carbamoyl}acetic acid methyl ester (14.0 mg, containing impurities) in methanol (1 ml) was added sodium methoxide (3.0 mg, 0.06 mmol), and the mixture was stirred for 2 hours. The reaction mixture was diluted with saturated ammonium chloride, and extracted with methylene chloride (30 ml and 15 ml). The organic layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The resultant residue was purified by preparative TLC (CH2Cl2/MeOH (10:1)) to give 3,4-difluoro-2-(2-fluoro-4-iodo-phenylamino)-5-{[(2-hydroxy-acetyl)-methoxy-amino]-methyl}-N-(2-hydroxy-ethoxy)-benzamide (F-5, 5.8 mg, 12% for 2 steps) as a colorless oil.
