[C:1]1([CH3:24])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH:7][C:8]1[O:9][C:10]2[CH:16]=[C:15]([CH2:17][CH2:18][C:19]([O:21]CC)=[O:20])[CH:14]=[CH:13][C:11]=2[N:12]=1.[OH-].[Na+]>CO>[C:1]1([CH3:24])[CH:6]=[CH:5][CH:4]=[CH:3][C:2]=1[NH:7][C:8]1[O:9][C:10]2[CH:16]=[C:15]([CH2:17][CH2:18][C:19]([OH:21])=[O:20])[CH:14]=[CH:13][C:11]=2[N:12]=1A solution of ethyl 3-(2-o-tolylamino-benzoxazol-6-yl)propanoate (Reference Example 15) in methanol (50 ml) was treated with aqueous sodium hydroxide (5 ml, 1M). After stirring at 40° C. for 2 hours the mixture was evaporated to low volume and partitioned between ethyl acetate (50 ml) and water (50 ml). The aqueous phase was separated and acidified with aqueous hydrochloric acid (10 ml, 1M). The resulting precipitate was dried at 60° C. to give the title compound (1.1 g).
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