[CH:1]([NH:3][C:4]1[S:5][CH:6]=[C:7]([C:9](=[N:15][O:16][CH2:17][S:18][CH3:19])[C:10]([O:12]CC)=[O:11])[N:8]=1)=[O:2].[OH-].Cl>CO>[CH:1]([NH:3][C:4]1[S:5][CH:6]=[C:7]([C:9](=[N:15][O:16][CH2:17][S:18][CH3:19])[C:10]([OH:12])=[O:11])[N:8]=1)=[O:2]A mixture of ethyl 2-(2-formamidothiazol-4-yl)-2-methylthiomethoxyiminoacetate (syn isomer, 2.4 g.), 1N aqueous soidum hydroxide (23.8 ml.) and methanol (19.8 ml.) was stirred at 30° C. for 2.5 hours. The resultant solution was adjusted to pH 7 with 10% hydrochloric acid and methanol was distilled off in vacuo. The aqueous solution was adjusted to pH 1 with 10% hydrochloric acid under ice cooling, and extracted with ethyl acetate three times. The extracts were washed with a saturated aqueous solution of sodium chloride, dried over magnesium sulfate and concentrated in vacuo to give 2-(2-formamidothiazol-4-yl)-2-methylthiomethoxyiminoacetic acid (syn isomer, 1.13 g.), mp. 157° C. (dec.).
読み込み中…