1-[1-(2-Thenoylmethyl)-2-oxo-5-cyclohexyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-3-yl]-3-(4-ethoxycarbonylphenyl)urea (0.70 g) was dissolved in tetrahydrofuran (19 ml), aqueous lithium hydroxide monohydrate (0.26 g) solution (15 ml) and methanol (7 ml) were added, the mixture was stirred at 40-50° C. for one hours. The reaction mixture was concentrated under reduced pressure, 1N hydrochloric acid and chloroform were added to the residue, and extracted. The organic layer was washed with water and saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, a mixed solvent of methylene chloride and ether (1:1) was added to powder so precipitated, and collected by filtration,to thereby obtain 0.61 g of the title compound (Yield: 92.4%).
