Cephalothin → HCID 13065698, compound

Participants

Reaction Steps

3-Acetoxymethyl-7β-(2-thienylacetamido)ceph-3-em-4-carboxylic acid (3.96 g, 10 m.moles) was dissolved in acetonitrile (50 ml) and dimethylacetamide (5ml). To this solution was added a mixture of isopropyl nitrite (2.4 g, 27 m.moles) and diphenylmethylamine (2.21 g, 12 m.moles) dissolved-suspended in acetonitrile (20 ml). The resulting slurry was stirred for 3 hours at 35°, after which time a solution resulted. The solvents were removed in vacuo and the gum redissolved in chloroform (50 ml). The resulting solution was washed with 5% sodium bicarbonate solution (50 ml), then water (50 ml) and the chloroform removed in vacuo. The gum was crystallised from hot isopropyl alcohol (28 ml), the crystals washed with cold isopropyl alcohol (25 ml) and then dried in vacuo at room temperature to give the title compound. Yield 3.19 g (56.8% based on the input acid); m. pt. and mixed m. pt. 140° - 140.5° with an authentic sample of the ester. The bicarbonate extract was washed with ethyl acetate (10 ml) and then acidified with 2N sulphuric acid at 5° to pH 1.2. The suspension was stirred for 30 minutes, filtered and washed with cold water (70 ml). The recovered starting material was dried in vacuo at room temperature, (0.9 g, single spot on t.l.c. by u.v. detection).

Provenance & Evidence