[S:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[C:2]1[C:10]1[O:11][C:12]([CH3:29])=[C:13]([CH2:15][CH2:16][O:17][C:18]2[CH:23]=[CH:22][C:21]([CH2:24][CH2:25][C:26]([OH:28])=O)=[CH:20][CH:19]=2)[N:14]=1.S(Cl)(Cl)=O.[NH2:34][C:35]([NH2:37])=[O:36]>>[S:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[C:2]1[C:10]1[O:11][C:12]([CH3:29])=[C:13]([CH2:15][CH2:16][O:17][C:18]2[CH:23]=[CH:22][C:21]([CH2:24][CH2:25][C:26]([NH:34][C:35]([NH2:37])=[O:36])=[O:28])=[CH:20][CH:19]=2)[N:14]=1To 3-[4-[2-(2-(benzothiophen-2-yl)-5-methyl-4-oxazolyl)ethoxy]phenyl]propionic acid (850 mg, 2.09 mmol) obtained in Example 14 was added thionyl chloride (2 ml, 27.4 mmol) and the mixture was stirred under heating for 40 min at 60° C. The reaction mixture was concentrated and N,N-dimethylaniline (10 ml) was added to the residue. Urea (250 mg, 4.17 mmol) was added and the mixture was stirred under heating for 5 hr at 150° C. Urea (250 mg, 4.17 mmol) was again added and the mixture was heated for 10 hr at 150° C. The reaction mixture was cooled to room temperature and the precipitated solid (468 mg) was collected by filtration. A part (260 mg) thereof was washed successively with water, ethyl acetate/tetrahydrofuran (9:1), 10% aqueous sodium hydroxide solution, 1N hydrochloric acid, water and tetrahydrofuran, and dried to give the title compound (110 mg, yield 21%) as a gray-white solid.
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