[CH3:1][O:2][C:3]1[CH:4]=[C:5]([C:9](=O)[C:10]([OH:12])=[O:11])[CH:6]=[CH:7][CH:8]=1.C(=O)(O)[O-].[Na+].Cl.[CH2:20]([O:22][NH2:23])[CH3:21].Cl>O>[CH2:20]([O:22][N:23]=[C:9]([C:5]1[CH:6]=[CH:7][CH:8]=[C:3]([O:2][CH3:1])[CH:4]=1)[C:10]([OH:12])=[O:11])[CH3:21]A solution of 2-(3-methoxyphenyl)glyoxylic acid (1.8 g.) in an aqueous solution of sodium bicarbonate was adjusted to pH 7.0. On the other hand, a solution of O-ethylhydroxylamine hydrochloride (1.4 g.) in water (20 ml.) was adjusted to pH 7.0 with sodium bicarbonate. Two solutions were combined together, adjusted to pH 5.5 with 10% hydrochloric acid and stirred overnight at ambient temperature. The reaction mixture was adjusted to pH 7.5 with sodium bicarbonate and washed with ethyl acetate. The aqueous layer was adjusted to pH 1.0 with conc. hydrochloric acid under ice-cooling and extracted with ethyl acetate. The extract was washed with ice-water and dried over magnesium sulfate. The solvent was distilled off under reduced pressure to give oil of 2-ethoxyimino-2-(3-methoxyphenyl)acetic acid (syn isomer) (2.2 g.).
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