[Na].[OH:2][N:3]=[C:4]([C:10]#[N:11])[C:5]([O:7][CH2:8][CH3:9])=[O:6].Cl[C:13]([O:15][CH3:16])=[O:14].C(=O)([O-])O.[Na+]>O.CC(C)=O>[CH3:16][O:15][C:13]([O:2][N:3]=[C:4]([C:10]#[N:11])[C:5]([O:7][CH2:8][CH3:9])=[O:6])=[O:14]
A solution of sodium salt of ethyl 2-hydroxyimino-2-cyanoacetate (41.0 g) in water (200 ml) is stirred under ice-cooling, and a solution of methyl chloroformate (23.6 g) in acetone (20 ml) is dropwise added thereto. The resulting mixture is adjusted to pH 6 to 7 with the addition of an aqueous solution of sodium hydrogencarbonate and stirred for 1 hour. The precipitates are collected by filtration, washed with water and dried to give ethyl 2-methoxycarbonyloxyimino-2-cyanoacetate (41.1 g) as crystals melting at 68° to 70°C which is identified with the compound obtained in Example 9 by IR absorption spectrum.
Wird geladen…
