N,O-bis(trimethylsilyl)acetamide → 7-[[(2-Amino-4-thiazolyl)-2-oxoacetyl]amino]-3-methylceph-3-em-4-carboxylic acid

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Reaction Steps

4.28 g of 7-amino-3-methylceph-3-em-4-carboxylic acid are suspended under a nitrogen atmosphere in 80 ml of dry dichloromethane, and mixed with 5.4 ml of N,O-bis(trimethylsilyl)acetamide. The preparation is stirred at room temperature until a clear solution is present, and then cooled to -15°. 8.4 g of 2-(2-amino-4-thiazolyl)-2-oxothioacetic-acid-S-benzothiazol-2-ylester are added, and stirred for one hour at -15°, one hour at 0° and then two hours at +20°. The solvent is carefully drawn off on a rotary evaporator, and the oily residue is rubbed with 50 ml of ethanol. The resultant deposit is filtered, washed with ethanol and ether, and vacuum dried at 40°. 5.3 g of the title compound are obtained as a yellow powder.

Provenance & Evidence