Hydrochloric Acid → 7alpha-Chloro-3-methyl-3-cephem-4-carboxylic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 7-ADCA (25 g, 0.117 mol), ethanol (700 ml), water (163 ml) and concentrated hydrochloric acid (163 ml) was cooled to 5° C. Sodium nitrite (11.5 g, 0.167 mol) was added in small portions over 25 minutes and the mixture was stirred for 3.5 hours at 0°-5° C.; 300 ml of brine was added and the reaction mixture was extracted with methylene chloride. The organic extract was washed with water, brine, dried over sodium sulfate and concentrated (16.1 g, 58.9%). This crude acid was directly used for the next step without further purification.

Herkunft & Nachweise