反应详情

2.64 g of the hydrochloride of 6-amino-1,4,5a,6-tetrahydro-3-hydroxy-1,7-dioxo-3H,7H-aceto[2,1-b]furo[3,4-d][1,3]thiazine (hydroxylactone of the hydrochloride of 7-amino-3-formyl-3-cephem-4-carboxylic acid) are dissolved in 50 ml of methanol. A solution of 0.78 g of pyridine in 10 ml of methanol is added dropwise to this solution whilst stirring and cooling with ice. The precipitated product is filtered off under nitrogen whilst excluding moisture, washed with a little methanol and dried over a drying agent in vacuo at room temperature. (6R-trans)-7-amino-3-formyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid is thus obtained in the form of a light brown powder. IR (KBr): 1799 cm-1 (β-lactam), 1672 cm-1 (CHO), 1606 and 1542 cm-1 (carboxylate) UV spectrum: λmax in H2O=302 nm.

1. temperaturecooling with ice
2. filtrationThe precipitated product is filtered off under nitrogen
3. washwashed with a little methanol
4. customdried over a drying agent in vacuo at room temperature