Phosphorus oxychloride → 4-Nitrobenzyl 7-[2-(2-formamidothiazol-4-yl)-2-isobutoxyiminoacetamido]-3-hydroxy-3-cephem-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

2-(2-Formamidothiazol-4-yl)-2-isobutoxyiminoacetic acid (syn isomer, 0.54 g.), N,N-dimethylformamide (0.16 g.), phosphoryl chloride (0.34 g.) and ethyl acetate (10 ml.) were treated in a similar manner to that of Example 15-(1) to give the activated acid solution. On the other hand, trimethylsilylacetamide (1.85 g.) and bis(trimethylsilyl)acetamide (1.62 g.) were added to a suspension of 4-nitrobenzyl 7-amino-3-hydroxy-3-cephem-4-carboxylate (0.7 g.) in ethyl acetate (10 ml.) and stirred at 40° C. for 30 minutes. The activated acid solution obtained above was added to the solution at -20° C. all at once, and stirred at the same temperature for an hour. Water (10 ml.) was added to the resultant solution, and the organic layer was separated, washed with water, an aqueous solution of sodium bicarbonate and a saturated aqueous solution of sodium chloride, and then dried. After the solution was concentrated in vacuo, the residue was pulverized with diisopropyl ether. The precipitates were collected by filtration, washed with diisopropyl ether and dried to give 4-nitrobenzyl 7-[2-(2-formamidothiazol-4-yl)-2-isobutoxyiminoacetamido]-3-hydroxy-3-cephem-4-carboxylate (syn isomer, 1.09 g.).

Provenance & Evidence