Methane → 3-[(Acetyloxy)methyl]-7-[[2-carboethoxy-2-(1-pyrryl)acetyl]amino]-8-oxo-5-thia-1-azabicyclo[4.2.0]-oct-2-ene-2-carboxylic acid

Beteiligte Stoffe

Reaktionsschritte

A solution of the monoethyl ester of 2(1-pyrryl) propanedioic acid (1 g., 5.07 mM) and 0.87 g. (5.2 mM) of N, N"-carbonyldiimidazole in 10 ml of dimethylformamide is stirred at room temperature for one hour. In a second flask, 3[(acetyloxy)methyl]-7-amino-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (1.37 g, 5.07 mM) is dissolved in 35 ml of chloroform upon the addition of 2.05 g (20.3 mM) of triethylamine and is stirred under nitrogen for 30 minutes in the presence of Linde 44 molecular sieves. The two solutions are combined and the mixture stirred for 4 hours after the addition of 0.5 g of charcoal. The reaction mixture is filtered, concentrated by flash evaporation and the residue is dissolved in 25 ml of water and washed several times with ether. The aqueous phase is covered with 50 ml of ethyl acetate and is then acidified to pH of 2.5 with 6 N hydrochloric acid. A small amount of solid is removed by filtration and the organic phase is separated, dried and concentrated to 5 ml. The title compound is obtained as a powder (425 mg., 19% yield) upon addition of the ethyl acetate solution to hexane.

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