Dicyclohexylcarbodiimide → N,N-Dimethylaniline

Beteiligte Stoffe

Reaktionsschritte

A mixture of 1.00 g (5.00 mmol) of (Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetic acid, 0.76 g (5.00 mmol) of 1-hydroxy-1H-benzotriazole hydrate, 1.14 g (5.50 mmol) of dicyclohexylcarbodiimide and 20 ml of N,N-dimethylformamide was stirred at room temperature for 2 hours. The obtained white solid was filtered and the filtrate was cooled to 0° C. The filtrate was added to mixed solution of 2.5 g (5.00 mmol) of 7-amino-3-(2,3-cyclopenteno-4-carbamoyl-1-pyridinium)methyl-3-cephem-4-carboxylate hydroiodic acid obtained in Preparation Example 24, 10 ml of N,N-dimethylformamide and 1.6 ml (12.70 mmol) of N,N-dimethylaniline. The mixture was stored at room temperature overnight and the precipitate was removed therefrom. The residue was dropped into 500 ml of diethylether with stirring. The precipitate was filtered, triturated with 100 ml of acetone and filtered again. The crude product thus obtained was dissolved in 100 ml of water and insoluble material was discarded by filtration. The resultant was freeze-dried to obtain 1.0 g of the same compound as obtained in Method a (yield: 37%).

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