Hydrochloric Acid → HCID 178477399, compound

Participants

Reaction Steps

To a suspension of 0.836 g (2 mmole) of sodium 7β-(2-thienylacetamido)-3-acetoxymethyl-3-cephem-4-carboxylate (sodium cephalothin) in 40 ml of dry methylene chloride maintained at the reflux temperature under a nitrogen atmosphere were added 0.7 ml (5.5 mmole) of chlorotrimethylsilane. The silylation of the C4 carboxy group was allowed to proceed 18 hours and the resulting yellow suspension was cooled to room temperature. The suspension was then reduced in volume by one-half under reduced pressure and 0.56 ml (4 mmole) of trimethylsilyl iodide were added rapidly. The color of the suspension gradually changed to a deep orange over one hour at room temperature. After 1.5 hours, 3 ml of dry dimethylformamide and 1 ml of propylene oxide were added to the orange suspension followed by 0.4 g (3.4 mmole) of 1-methyltetrazole-5-thiol. The reaction of the tetrazole thiol with the 3-iodomethyl derivative was allowed to proceed at room temperature for one hour after which 20 ml of methylene chloride and 20 ml of cold dilute hydrochloric acid (pH2) were added to the black reaction solution. The mixture was stirred vigorously for 20 minutes, was filtered and the organic layer separated. The organic layer was washed repeatedly with cold brine, dried over sodium sulfate and was filtered. Concentration of the organic layer afforded trimethylsilyl 7β-(2-thienylacetamido)-3-(1-methyl-1H-tetrazole-5-ylthiomethyl)-3-cephem-4-carboxylate contaminated with some DMF and 2-iodo-1-trimethylsilylpropanol.

Provenance & Evidence