Ammonia → 7-Amino-3-(1-methyltetrazol-5-ylthiomethyl)-3-cephem-4-carboxylicacid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A 3.5 ml portion of acetonitrile was added to 0.570 g of dihydrate of 5-mercapto-1-methyl-1H-tetrazole sodium salt and 0.680 g of 7-ACA, and 1.64 g of diphosphoryl tetrachloride was added dropwise to the mixture under cooling over an external bath at -30° to -20° C., followed by adding 2.29 g of DCPA and rinsing with 0.5 ml of acetonitrile. The reaction solution was stirred at -5° to 0° C. for 5 minutes, warmed at 25° C., and stirred for 40 minutes to allow the reaction to proceed. The reaction solution was cooled and poured into ice-water, which was placed in a refrigerator overnight. The mixture was adjusted to pH 4.0 with 25% aqueous ammonia, and the resultant precipitate was recovered by filtration, washed with cold water and acetone successively and dried, thereby affording 0.732 g (89.3% of yield) of 7-amino-3-(1-methyl-1H-tetrazol-5 -yl)thiomethyl-3-cephem-4-carboxylic acid. The NMR values of the product were in accordance with those of the authentic sample.

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