Sodium Chloride → 3-Acetoxymethyl-7-chloro-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-2-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To an ice-cooled solution of t-butyl 7β-amino-3-acetoxymethyl-3-cephem-4-carboxylate (4.0 g, 0.0122 mol) in 75 ml of ethanol, 16.7 ml of water and 16.7 ml of concentrated hydrochloric acid and sodium nitrite (1.18 g, 0.017 mol) were added portionwise over 15-20 minutes. The reaction mixture was stirred at 0°-5° C. for 2.5 hours, saturated with sodium chloride, extracted with methylene chloride, washed with water, brine, dried (Na2SO4) and concentrated to give 3.1 g (73%) of t-butyl 7α-chloro-3-acetoxymethyl-3-cephem-4-carboxylate.

Provenance & Evidence