A portion (200 mg) of the compound obtained in Example 81 and N-t-butoxycarbonylglycine (170 mg) were suspended in methylene chloride (15 ml) and to the suspension was added dichlorohexylcarbodiimide (216 mg) under cooling with ice. The mixture was stirred for 1 hour at room temperature. To the reaction mixture was added water, followed by extraction with ethyl acetate. The organic layer was washed with water and saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. Then, the solvent was distilled off under reduced pressure to yield the titled compound (470 mg) as a crude yellow solid. The compound was used in the subsequent reaction without further purification.
