Water → (2-methoxy-2-methylpropanoyl)oxymethyl (6R,7R)-3-(carbamoyloxymethyl)-7-[[(2Z)-2-(furan-2-yl)-2-methoxyiminoacetyl]amino]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate

関与物質

反応手順

Cefuroxime (1.697 g) and powdered potassium carbonate (276 mg) were stirred in anhydrous N,N-dimethylformamide (20 ml) at 22° for 1 hour and the resulting solution was cooled in an ice/salt bath to -8°. A solution of crude 2-methoxy-2-methylpropanoic acid iodomethyl ester (1.52 g) in anhydrous N,N-dimethylformamide (6 ml) was added and the solution was stirred for 35 mins. Water (75 ml) was added and the mixture was extracted with ethyl acetate (2×100 ml). The combined organic layers were washed successively with 50 ml each of 2N hydrochloric acid (3×), water, saturated aqueous sodium bicarbonate, water, 10% aqueous sodium metabisulphite, water (2×) and saturated brine, dried over magnesium sulphate and concentrated under vacuum to ca 10 ml. The solution was added dropwise to stirred petroleum ether (100 ml) to give a precipitate which was filtered off, washed with petroleum ether and dried under reduced pressure to give the title ester (1.532 g); λmax (ethanol 277) nm E11 323; νmax (CHBr3) 3520 and 3400 (NH and NH2), 1788 (β-lactam C=O); 1735 (ester and carbamate C=O) and 1685 and 1510 cm-1 (amide C=O).

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