Cephalothin → HCID 14831642, compound

Participants

Reaction Steps

To a solution of 3-acetoxymethyl-7β-(2-thienylacetamido) ceph-3-em-4-carboxylic acid (3.96 g., 10 m. moles) in acetonitrile (70 ml) and dimethylacetamide (5 ml) was added benzylamine (1.28 g., 12 m. moles) and isobutyl nitrite (2.47 g., 24 m. moles) and the mixture heated to 45° over 2 hours. Initially a solid formed in the mixture but with vigorous stirring it had all dissolved after 1-1.25 hours as the reaction proceeded. After removal of the solvent in vacuo, the gum was taken up in ethyl acetate (50 ml) washed with dilute H2SO4 (25 ml.), 5% NaHCO3 solution (50 ml.) and water (50 ml.), and the organic residue after evaporation of the organic solvent crystallised from hot isopropanol to yield the title ester (2.40 g., 42% based on the input acid) m.pt. 135° - 139°. T.l.c. indicated the presence of some trace impurities.

Provenance & Evidence