Hydrochloric Acid → (6R)-8-Oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

7-amino-3-(sulfomethyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (5 g), was dissolved in water (19 ml) using 30% w/w sodium hydroxide (1.5 g in 8 ml water) and sodium bicarbonate (1 g), O-formylmandeloyl chloride (2.45 g) was added at 0-5° C. and maintained at 5-10° C. over a period of 1-2 hours. After the completion of reaction, the reaction mixture was acidified with conc. HCl (2.6 g) and maintained the reaction at 28-30° C. for about 2-3 hours. After the completion of reaction, sodium bicarbonate (˜3.5 g) was added to set the pH 5±1 and the solution was added to a solution of N,N′-dicyclohexylethylenediamine diacetate (9.26 g) in water (40 mL) and isopropyl alcohol (40 mL) and stirred well at 25-30° C. for about 2-3 hours. The reaction mixture was cooled to 5-10° C., filtered, washed with chilled water (0-5° C.) and isopropyl alcohol (0-5° C.) and dried the material under vacuum at ˜40° C. to get N,N′-dicyclohexylethylenediamine salt of 7-D-mandelamido-3-(1-sulfomethyl-1H-tetrazol-5-yl)thio)methyl)-3-cephem-4-carboxylic acid (6.5 g). Step-(ii)

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