[NH2:1][C:2]1[S:3][CH:4]=[C:5]([C:7](=[N:13][O:14][CH:15]2[CH2:17][CH2:16]2)[C:8]([O:10]CC)=[O:9])[N:6]=1.[OH-].[Na+].Cl>O1CCOCC1.C(O)C>[NH2:1][C:2]1[S:3][CH:4]=[C:5]([C:7](=[N:13][O:14][CH:15]2[CH2:17][CH2:16]2)[C:8]([OH:10])=[O:9])[N:6]=1
To a solution of ethyl 2-(2-aminothiazol-4-yl)-2-(cyclopropyloxyimino)acetate (syn isomer)(1.88 g) in 1,4-dioxane (16.7 ml) was added 1N sodium hydroxide (16.7 ml). The mixture was stirred for 1.5 hours at 33° C. After the mixture was cooled under ice-bath, 1N hydrochloric acid (16.7 ml) was added to the mixture. The mixture was concentrated in vacuo to give a residue. The residue was suspended in ethanol, concentrated in vacuo and triturated with ethyl acetate to give crude 2-(2-aminothiazol-4-yl)-2-(cyclopropyloxyimino)acetic acid (syn isomer)(2.63 g). This compound was used for Preparation 33 without further purification.
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