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

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Reaction Conditions

Reaction Steps

α-(Benzyloxycarbonyl)amino-4-hydroxy-3-(methoxymethyl)benzeneacetic acid (0.1 mole) is dissolved in tetrahydrofuran (THF). The temperature of the solution is maintained at about -10° C. and 0.2 mole of isobutylchloroformate is added. After stirring for about 30 minutes at -10° C., 0.1 mole of 6-amino-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid in a 50/50 THF/water solution containing 0.1 mole of triethylamine is added to the above formed solution. This mixture is stirred for 30 minutes at -10° C. and then the temperature is raised to about 20° C. Stirring is continued for an additional 30 minutes. The pH is adjusted to 4.5 to 5.5, and the coupled product is extracted into ethyl acetate. The ethyl acetate is dried over magnesium sulfate, filtered and evaporated to give the coupled product, 6-[[(benzyloxycarbonyl)amino]-hydroxy-3-(methoxymethyl)-phenyl]acetyl]amino]-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylic acid.

Provenance & Evidence