Phosphorus oxychloride → HCID 88737824, compound

Participants

Reaction Steps

N,N-Dimethylformamide (88 mg) and phosphorus oxychloride (184 mg) were mixed to prepare Vilsmeier reagent in a conventional manner, and the resultant Vilsmeier reagent was suspended in dry tetrahydrofuran (10 ml). To the suspension was added 2-(2-formamidothiazol-4-yl)glyoxylic acid (0.2 g) under ice-cooling with stirring, and the solution was stirred at the same temperature for 30 minutes to prepare the activated acid solution. 4-Nitrobenzyl 7-amino-3-chloro-3-cephem-4-carboxylate (0.4 g) was dissolved in a solution of trimethylsilylacetamide (1.0 g) in ethyl acetate (100 ml). To the solution was added the activated acid solution obtained above all at once at -20° C., and the solution was stirred at -20° to -5° C. for 1.5 hours. After water and ethyl acetate (50 ml) were added to the resultant solution at -20° C., the insoluble substance was separated by filtration, washed with water and acetone in turn and then dried to give 4-nitrobenzyl 7-[2-(2-formamidothiazol-4-yl)glyoxyloylamino]-3-chloro-3-cephem-4-carboxylate (0.1 g).

Provenance & Evidence