[C:1]([NH:9][C:10]1[S:11][C:12]([C:16]([O:18]CC)=[O:17])=[C:13]([CH3:15])[N:14]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[OH-].[Li+].C(O)(=O)C>O1CCCC1.O>[C:1]([NH:9][C:10]1[S:11][C:12]([C:16]([OH:18])=[O:17])=[C:13]([CH3:15])[N:14]=1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1A mixture of ethyl 2-benzamido-4-methylthiazole-5-carboxylate (3.00 g, 10.00 mmol) and lithium hydroxide (2.50 g, 103.00 mmol) in a mixture of tetrahydrofuran (40 mL) and water (10 mL) was stirred at 50° C. for 20 h. The mixture was then cooled to 0° C. and neutralized with acetic acid to pH 7. The precipitate obtained was collected by filtration, washed with water and dried in vacuo to afford the title compound as a white solid in 75% yield (2.0 g); 1H NMR (DMSO-d6, 300 MHz) δ 12.92 (s, br, 1H), 8.06-8.04 (m, 2H), 7.63-7.48 (m, 3H), 2.53 (s, 3H).
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