反应详情

22.4 g (0.1 mol) of (4-Methylsulfanyl-phenyl)-oxo-acetic acid ethyl ester and 7.6 g (0.1 mol) of hydroxylammonium hydrochloride are dissolved in 180 ml of pyridine and the mixture is stirred at room temperature for 16 hours. The yellowish solution is diluted with water and ethyl acetate, the organic phase separated and the aqueous phase extracted several times with ethyl acetate. The combined organic extracts are washed with diluted hydrogen chloride and water and the solvent is evaporated. 24 g (100%) of crude hydroxyimino-(4-methylsulfanyl-phenyl)-acetic acid ethyl ester (66:34 mixture of the E and Z-isomers) are thus obtained and used in the next step without further purification. The structure is confirmed by the 1H-NMR spectrum (in CDCl3). δ[ppm]: 7.46 (d,2H), 7.19 (d,2H), 4.44 (E) and 4,32 (Z) (two d,2H) 2.47 (Z) and 2.46 (E) (s,3H) 1.37 (E) and 1.28 (Z) (t,3H).

1. customthe organic phase separated
2. extractionthe aqueous phase extracted several times with ethyl acetate
3. washThe combined organic extracts are washed with diluted hydrogen chloride and water
4. customthe solvent is evaporated
5. addition24 g (100%) of crude hydroxyimino-(4-methylsulfanyl-phenyl)-acetic acid ethyl ester (66:34 mixture of the E and Z-isomers)
6. customare thus obtained
7. customused in the next step without further purification