30 mg of 10% palladium-carbon was added to a solution of 350 mg (1 mmol) of N—[N-[(phenylmethoxy)carbonyl]-L-leucyl]-L-valinol obtained in Reference Example 184 in 10 ml of methanol, and the mixture was stirred under a hydrogen atmosphere at room temperature overnight. After the reaction solution was filtered, the filtrate was concentrated under reduced pressure. 10 ml of ethyl acetate, 10 ml of water and further 159 mg (1.5 mmol) of sodium carbonate were added to the residue. Under ice-cooling, a solution of 131 mg (1 mmol) of 2-furancarbonyl chloride in 3 ml of ethyl acetate was added to the mixture solution. The reaction solution was returned to room temperature and stirred overnight. The aqueous layer of the reaction solution was separately collected and it was extracted with ethyl acetate. The organic layer was combined, and after it was washed with a 10% potassium hydrogensulfate and then saturated brine, it was dried with anhydrous sodium sulfate. The solvent was distilled off under reduced pressure and ether was added to the residue to wash the crystal to obtain 268 mg (86%) of the title compound.
