Yield: 71%

Reaction Conditions:

with sodium hydroxide in water at 15 - 20;

Steps:

2.2.1 2-(2-Aminothiazole-4-yl)-2-(anti)-hydroxyiminoacetic acid (anti-A) and 2-(2-aminothiazole-4-yl)-2-(syn)-hydroxyiminoacetic acid (syn-A)
General procedure: To a solution of NaOH (2.4g, 0.06mol) in water (100mL) was added ethyl 2-(2-aminothiazole-4-yl)-2-(anti)-hydroxyiminoacetate [22] or ethyl 2-(2-aminothiazole-4-yl)-2-(syn)-hydroxyiminoacetate [23] (10.76g, 0.05mol) with stirring in an ice bath. The mixture was stirred for 2-3h at 15-20°C, after that the solvent was removed in vacuum. The solid residue was dissolved in H₂ (100mL), treated with Norit (1.0g) and filtered. The glacial acetic acid was added dropwise to the filtrate with stirring till neutral reaction. The resulting precipitate was filtered off, washed with water and recrystallized twice from the ethanol.

References:

Orysyk;Zholob;Bon;Nikulina;Orysyk;Nikolaienko;Garmanchuk;Zborovskii, Yu.L.;Tolstanova;Khranovska;Pekhnyo;Vovk [Polyhedron,2015,vol. 85,p. 208 - 220]