[C:1]1([C:7]2[N:8]=[C:9]([CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][C:25]([O:27]C)=[O:26])[O:10][C:11]=2[C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[OH-].[Na+].CO.Cl>O>[C:1]1([C:7]2[N:8]=[C:9]([CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH2:24][C:25]([OH:27])=[O:26])[O:10][C:11]=2[C:12]2[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1A mixture of methyl 4,5-diphenyl-2-oxazoleoctanoate (7.00 g, 18.5 mmol), 5N sodium hydroxide solution (7.42 mL), water (100 mL) and methanol (20 mL) was heated on a steam bath for 45 minutes. After stirring at room temperature for 75 minutes, the mixture was diluted with water (150 mL), heated on a steam bath for 10 minutes and then allowed to stir overnight at room temperature. The mixture was heated to reflux for 1 hour, cooled, acidified with 2N hydrochloric acid solution and extracted with CH2Cl2. The combined extracts were dried over sodium sulfate and concentrated in vacuo to give an oil that crystallized. Recrystallization from a mixture of diethyl ether, CH2Cl2 and hexanes furnished 4,5-diphenyl-2-ozazoleoctanoic acid (5.25 g, 77%), m.p. 70°-73° C.
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