Acetamide, 2-(trimethylsilyl)- → HCID 178502761, compound

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Reaction Steps

On the other hand, 7-amino-3-(1-methyl-1H-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid and trimethylsilylacetamide (11 g.) were added to methylene chloride (66 ml.) and the mixture was stirred at ambient temperature for an hour, and to this solution was added all at once the above activated solution of 2-(4-formamidopyrimidin-2-yl)-2-methoxyiminoacetic acid under cooling at -20° C. with stirring, and the stirring was continued at the same temperature for an hour and at ambient temperature for additional an hour. The reaction mixture was concentrated under reduced pressure and then ethyl acetate and an aqueous solution of sodium bicarbonate were added to adjust the solution to pH 7 to 8. After the aqueous layer was separated out, a proper quantity of ethyl acetate was added thereto. The mixture was adjusted to pH 1 to 2 with dilute hydrochloric acid and then salted out. The ethyl acetate layer was separated out, washed with an aqueous solution of sodium chloride and dried over magnesium sulfate, and then evaporated to dryness under reduced pressure. The resultant foamy substance was pulverized in ethyl ether, collected by filtration and then dried to give 7-[2-(4-formamidopyrimidin-2-yl)-2-methoxyiminoacetamido]-3-(1-methyl-1H-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid (2.9 g.). Thus obtained product (0.6 g.) was dissolved in a mixed solution of methanol and ethyl acetate (5 ml.) (2:1 by volume), and the solution was poured into ethyl ether (40 ml.) and then the mixture was allowed to stand for a while. The precipitates were collected by filtration to give purified pale-yellowish powder of 7-[2-(4-formamidopyrimidin-2-yl)-2-methoxyiminoacetamido]-3-(1-methyl-1H-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylic acid (a mixture of syn and anti isomers) (0.5 g.).

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