Acetic Anhydride → HCID 131710690, compound

Participants

Reaction Steps

3-Acetoxymethyl-7β-formamidoceph-3-em-4-carboxylic acid (3.0 g., 1 mmol.) was suspended in dry pyridine (12 ml) at room temperature. Acetic anhydride (1.2 ml.) was added to the stirred suspension and the reaction allowed to proceed for 1 hr. On cooling with ice, the pyridinium salt crystallised and this was filtered off. Treatment of the solid with dilute hydrochloric acid and extraction with ethyl acetate gave the free acid which was obtained as a gum after washing the organic phase with water, drying, and evaporation. The gum (0.61 g 20.3%) could not be crystallised. The spectroscopic properties of the product are consistent with the structure of the compound named in the title νmax (film) 3300 (NH), 1770 (β-lactam), 1730 (OCOCH3), 1675 cm-1 (HCON--) τ (D2O/NaHCO3) 1.82 (singlet, HCO--), 3.52 (singlet, =CH--S), 4.51 and 4.71 (double doublet, J=4 Hz, 6H and 7H protons), 5.22 (collapsed quartet), 5.82 (singlet, CHCO2H) and 7.89 (singlet, CH3COO--).

Provenance & Evidence