Hydrochloric Acid → (6R)-7-[[(2Z)-2-(2-amino-1,3-thiazol-4-yl)-2-hydroxyiminoacetyl]amino]-3-ethenyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

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Reaction Steps

40 g of 7-amino-3-vinyl-3-cephem-4-carboxylic acid in 400 ml of dichloromethane are treated with 55.7 ml of N,O-bistnmethyl-silylacetamid. The mixture obtained is stirred for ca. 2 hours at room temperature, cooled to 0° and treated with 52.2 g of 2-(Z)-(2-aminothiazol-4-yl) -2-acetoxyiminoacetic acid chloride in the form of a hydrochloride in small portions. The mixture obtained is stirred for ca.90 minutes at 0° and added under stirring to a mixture of 44.55 g of NaHCO3, 600 ml of water und 100 ml of dichloromethane of a temperature of 5°. The pH of the mixture obtained is adjusted to a pH of ca. 7.2-7.3 with a saturated aqueous solution of NaHCO3. The phases formed are separated. To the aqueous phase 300 ml of water are added and 28.7 g of NH4Cl. The pH of the mixture obtained is adjusted to pH 8 by addition of an aqueous 10% K2CO3 solution and the mixture is stirred for ca. 80 minutes. A solution is obtained. The pH of the solution obtained is adjusted to pH 3 by addition of 5 m sulphuric acid. 7-(Z)-[2-(2-amino-thiazol4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid precipitates, is filtrated off, washed with water and dried. 7-(Z)-[2-(2-amino-thiazol-4-yl)-2-hydroxyiminoacetamido]-3-vinyl-3-cephem-4-carboxylic acid in a purity of 94.3 % is obtained.

Provenance & Evidence