N,N-Dimethylaniline → 7-amino-3-(1-allyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid

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Reaction Steps

N,N-Dimethylaniline (18.2 ml) was added to a mixture of ammonium 7-(5-amino-5-carboxyvaleramido)-3-(1-allyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylate (10.0 g), trimethylsilyl chloride (20.9 ml) and methylene chloride (75 ml), and the mixture was stirred under reflux for 2.5 hours. Phosphorus pentachloride (5.83 g) was added thereto at -30° to -35° C. and the mixture was stirred for 2 hours at the same temperature. 2-Ethoxyethanol (38 ml) was added dropwise thereto at the same temperature and the mixture was stirred for 1 hour at the same temperature. Water (80 ml) was added thereto at -5° to -10° C. over 10 minutes and the resulting mixture was stirred for 5 minutes at the same temperature. The aqueous layer was separated and adjusted to pH 4.2 with 28% aqueous solution of ammonia. Precipitates were collected by filtration, washed with 70% aqueous acetone (40 ml) and methanol (40 ml), and dried to give 7-amino-3-(1-allyl-1H-tetrazol-5-yl)thiomethyl-3-cephem-4-carboxylic acid (4.1 g).

Provenance & Evidence