Phosphorus oxychloride → 7-[2-(2-Formamidothiazol-4-yl)-2-(2-azidoethoxyimino)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid

Participants

Reaction Steps

2-(2-Formamidothiazol-4-yl)-2-(2-azidoethoxyimino)acetic acid (syn isomer, 0.70 g.), N,N-dimethylformamide (0.21 ml.), phosphoryl chloride (0.4 g.) and ethyl acetate (15.8 ml.) were treated in a similar manner to that of Example 1-(1) to give an activated acid solution. The solution was added to a solution of 7-amino-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (0.74 g.) and trimethylsilylacetamide (2.0 g.) in ethyl acetate (15 ml.) at -10° to -15° C. and stirred at the same temperature for an hour. After adding water (30 ml.) to the resultant solution, the organic layer was separated, washed with a saturated aqueous solution of sodium chloride dried over magnesium sulfate and evaporated in vacuo to give 7-[2-(2-formamidothiazol-4-yl)-2-(2-azidoethoxyimino)acetamido]-3-(1,3,4-thiadiazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer, 1.08 g.).

Provenance & Evidence