6-Amino-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo(3.2.0)heptane-2-carboxylic acid → 6-[[[3-(Azidomethyl)-4-hydroxyphenyl]hydroxyacetyl]amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

α-Hydroxy-3-(azidomethyl)-4-hydroxybenzeneacetic acid (30 mmole) is dissolved in tetrahydrofuran (THF). To this solution is added (45 mmole) bistrimethylsilylacetamide and (30 mmole) triethylamine. The mixture is refluxed for 2 hours after which the reaction mixture is cooled to about -10° C. and 30 mmole of isobutylchloroformate is added dropwise. After 30 mixtures at -10° C., 30 mmole of 6-amino-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo [3.2.0]heptane-2-carboxylic acid in 50 ml of THF-20 ml of water containing 30 mmole of triethylamine is added to the previously prepared solution at -10° C. The temperature of the reaction mixture is allowed to warm from -10° C. to room temperature over one hour. About 50 ml of saturated sodium bicarbonate and 100 ml of water are added to the reaction mixture which is twice extracted with ether. The aqueous phase is layered with ethyl acetate and the pH is adjusted to 1.5 by the addition of hydrochloric acid. The ethyl acetate is separated from the aqueous phase, dried over sodium sulfate, filtered and evaporated to give the title compound.

Provenance & Evidence